Vitamin D3 – Uses, Dosage, Side Effects, Interactions

Last updated: February 8, 2026Reviewed date: February 8, 2026Reading time: 43 min read
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Cholecalciferol is a steroid hormone produced in the skin when exposed to ultraviolet light or obtained from dietary sources. The active form of cholecalciferol, 1,25-dihydroxycholecalciferol (calcitriol) plays an important role in maintaining blood calcium and phosphorus levels and mineralization of bone. The activated form of cholecalciferol binds to vitamin D receptors and modulates gene expression....

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বাংলা রোগী নোট এখনো যোগ করা হয়নি। পোস্ট এডিটরে “RX Bangla Patient Mode” বক্স থেকে সহজ বাংলা সারাংশ যোগ করুন।

এই তথ্য শিক্ষা ও সচেতনতার জন্য। এটি ডাক্তারি পরীক্ষা, রোগ নির্ণয় বা প্রেসক্রিপশনের বিকল্প নয়।

Article Summary

Cholecalciferol is a steroid hormone produced in the skin when exposed to ultraviolet light or obtained from dietary sources. The active form of cholecalciferol, 1,25-dihydroxycholecalciferol (calcitriol) plays an important role in maintaining blood calcium and phosphorus levels and mineralization of bone. The activated form of cholecalciferol binds to vitamin D receptors and modulates gene expression. This leads to an increase in serum calcium concentrations by increasing intestinal absorption of phosphorus and calcium, promoting distal renal tubular reabsorption of calcium and increasing osteoclastic...

Key Takeaways

  • This article explains Mechanism of Action in simple medical language.
  • This article explains Indications in simple medical language.
  • This article explains Contraindications in simple medical language.
  • This article explains Dosages in simple medical language.
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Cholecalciferol is a steroid hormone produced in the skin when exposed to ultraviolet light or obtained from dietary sources. The active form of cholecalciferol, 1,25-dihydroxycholecalciferol (calcitriol) plays an important role in maintaining blood calcium and phosphorus levels and mineralization of bone. The activated form of cholecalciferol binds to vitamin D receptors and modulates gene expression. This leads to an increase in serum calcium concentrations by increasing intestinal absorption of phosphorus and calcium, promoting distal renal tubular reabsorption of calcium and increasing osteoclastic resorption.

Vitamin D, in general, is a secosteroid generated in the skin when 7-dehydrocholesterol located there interacts with ultraviolet irradiation – like that commonly found in sunlight. Both the endogenous form of vitamin D (that results from 7-dehydrocholesterol transformation), vitamin D3 (cholecalciferol), and the plant-derived form, vitamin D2 (ergocalciferol), are considered the main forms of vitamin d and are found in various types of food for daily intake. Structurally, ergocalciferol differs from cholecalciferol in that it possesses a double bond between C22 and C23 and has an additional methyl group at C24. Finally, ergocalciferol is pharmacologically less potent than cholecalciferol, which makes vitamin D3 the preferred agent for medical use. Appropriate levels of vitamin D must be upheld in the body in order to maintain calcium and phosphorus levels in a healthy physiologic range to sustain a variety of metabolic functions, transcription regulation, and bone metabolism. However, studies are also ongoing to determine whether or not cholecalciferol may also play certain roles in cancer, autoimmune disorders, cardiovascular disease, and other medical conditions that may be associated with vitamin D deficiency.

Mechanism of Action

Most individuals naturally generate adequate amounts of vitamin D through ordinary dietary intake of vitamin D (in some foods like eggs, fish, and cheese) and natural photochemical conversion of the vitamin D3 precursor 7-dehydrocholesterol in the skin via exposure to sunlight. Conversely, vitamin D deficiency can often occur from a combination of insufficient exposure to sunlight, inadequate dietary intake of vitamin D, genetic defects with endogenous vitamin D receptor, or even severe liver or kidney disease. Such deficiency is known for resulting in conditions like rickets or osteomalacia, all of which reflect inadequate mineralization of bone, enhanced compensatory skeletal demineralization, resultant decreased calcium ion blood concentrations, and increases in the production and secretion of parathyroid hormone. Increases in parathyroid hormone stimulate the mobilization of skeletal calcium and the renal excretion of phosphorus. This enhanced mobilization of skeletal calcium leads towards porotic bone conditions. Ordinarily, while vitamin D3 is made naturally via photochemical processes in the skin, both itself and vitamin D2 can be found in various food and pharmaceutical sources as dietary supplements. The principal biological function of vitamin D is the maintenance of normal levels of serum calcium and phosphorus in the bloodstream by enhancing the efficacy of the small intestine to absorb these minerals from the diet. At the liver, vitamin D3 or D2 is hydroxylated to 25-hydroxyvitamin D and then finally to the primary active metabolite 1,25-dihydroxyvitamin D in the kidney via further hydroxylation. This final metabolite binds to endogenous vitamin d receptors, which results in a variety of regulatory roles – including maintaining calcium balance, the regulation of parathyroid hormone, the promotion of the renal reabsorption of calcium, increased intestinal absorption of calcium and phosphorus, and increased calcium and phosphorus mobilization of calcium and phosphorus from bone to plasma to maintain balanced levels of each in bone and the plasma. In particular, calcitriol interacts with vitamin D receptors in the small intestine to enhance the efficiency of intestinal calcium and phosphorous absorption from about 10-15% to 30-40% and 60% increased to 80%, respectively. Furthermore, calcitriol binds with vitamin D receptors in osteoblasts to stimulate a receptor activator of nuclear factor kB ligand (or RANKL) which subsequently interacts with receptor activator of nuclear factor kB (NFkB) on immature preosteoclasts, causing them to become mature bone-resorbing osteoclasts. Such mature osteoclasts ultimately function in removing calcium and phosphorus from bone to maintain blood calcium and phosphorus levels. Moreover, calcitriol also stimulates calcium reabsorption from the glomerular filtrate in the kidneys. Additionally, it is believed that when calcitriol binds with nuclear vitamin D receptors, that this bound complex itself binds to retinoic acid X receptor (RXR) to generate a heterodimeric complex that consequently binds to specific nucleotide sequences in the DNA called vitamin D response elements. When bound, various transcription factors attach to this complex, resulting in either up or down-regulation of the associated gene’s activity. It is thought that there may be as much as 200 to 2000 genes that possess vitamin D response elements or that are influenced indirectly to control a multitude of genes across the genome. It is in this way that cholecalciferol is believed to function in regulating gene transcription associated with cancer risk, autoimmune disorders, and cardiovascular disease linked to vitamin D deficiency. In fact, there has been some research to suggest calcitriol may also be able to prevent malignancies by inducing cellular maturation and inducing apoptosis and inhibiting angiogenesis, exhibit infection, or irritation, often causing pain, swelling, heat, or redness. সহজ বাংলা: শরীরের প্রদাহ; ব্যথা, ফোলা বা লালভাব হতে পারে।" data-rx-term="inflammation" data-rx-definition="Inflammation is the body’s response to injury, infection, or irritation, often causing pain, swelling, heat, or redness. সহজ বাংলা: শরীরের প্রদাহ; ব্যথা, ফোলা বা লালভাব হতে পারে।">inflammation, pain, or swelling. সহজ বাংলা: প্রদাহ/ফোলা/ব্যথা কমায়।" data-rx-term="anti-inflammatory" data-rx-definition="Anti-inflammatory means reducing inflammation, pain, or swelling. সহজ বাংলা: প্রদাহ/ফোলা/ব্যথা কমায়।">anti-inflammatory effects by inhibiting foam cell formation and promoting angiogenesis in endothelial colony-forming cells in vitro, inhibit immune reactions by enhancing the transcription of endogenous antibiotics like cathelicidin and regulate the activity and differentiation of CD4+ T cells, amongst a variety of other proposed actions.
The principal biologic function of vitamin D is to maintain serum calcium and phosphorus concentrations within the normal range by enhancing the efficiency of the small intestine to absorb these minerals from the diet. Calcitriol (activated vitamin D) enhances the efficiency of intestinal calcium absorption along the entire small intestine, but principally in the duodenum and jejunum. Calcitriol also enhances phosphorus absorption along the entire small intestine, but principally in the jejunum and ileum. The activated forms of ergocalciferol, doxercalciferol, and cholecalciferol may have a negative feedback effect on parathyroid hormone (PTH) production.

Pharmacodynamics

The in vivo synthesis of the predominant two biologically active metabolites of vitamin D occurs in two steps. The first hydroxylation of vitamin D3 cholecalciferol (or D2) occurs in the liver to yield 25-hydroxyvitamin D while the second hydroxylation happens in the kidneys to give 1, 25-dihydroxyvitamin D. These vitamin D metabolites subsequently facilitate the active absorption of calcium and phosphorus in the small intestine, serving to increase serum calcium and phosphate levels sufficiently to allow bone mineralization. Conversely, these vitamin D metabolites also assist in mobilizing calcium and phosphate from bone and likely increase the reabsorption of calcium and perhaps also of phosphate via the renal tubules. There exists a period of 10 to 24 hours between the administration of cholecalciferol and the initiation of its action in the body due to the necessity of synthesis of the active vitamin D metabolites in the liver and kidneys. It is parathyroid hormone that is responsible for the regulation of such metabolism at the level of the kidneys.

Metabolic activation of cholecalciferol and ergocalciferol occurs in 2 steps, the first in the liver and the second in the kidneys. Metabolic activation of calcifediol occurs in the kidneys; dihydrotachysterol, alfacalcidol and doxercalciferol are activated in the liver.

Indications

  1. Cholecalciferol use is indicated for the treatment of specific medical conditions like refractory rickets (or vitamin D resistant rickets), hypoparathyroidism, and familial hypophosphatemia. Concurrently, as one of the most commonly utilized forms of vitamin D, cholecalciferol is also very frequently used as a supplement in individuals to maintain sufficient vitamin d levels in the body or to treat vitamin D deficiency, as well as various medical conditions that can be associated directly or indirectly with vitamin d insufficiency like fracture risk. সহজ বাংলা: হাড় দুর্বল হয়ে ভাঙার ঝুঁকি বেশি।" data-rx-term="osteoporosis" data-rx-definition="Osteoporosis means weak, fragile bones with higher fracture risk. সহজ বাংলা: হাড় দুর্বল হয়ে ভাঙার ঝুঁকি বেশি।">osteoporosis and chronic kidney disease, among others.
  2. Vitamin D insufficiency and deficiency are prevalent worldwide; thus, regular monitoring of vitamin D levels is recommended for individuals at risk of insufficiency and deficiency. Vitamin D deficiency is associated with an increased risk of cardiovascular disease, type 2 insulin is low or not working well. সহজ বাংলা: রক্তে চিনি বেশি থাকার রোগ।" data-rx-term="diabetes" data-rx-definition="Diabetes is a condition where blood sugar stays too high because insulin is low or not working well. সহজ বাংলা: রক্তে চিনি বেশি থাকার রোগ।">diabetes, cancer, depression, and cognitive impairment. Individuals experiencing mild vitamin D deficiency may exhibit symptoms such as fatigue, joint pains, and depression. In cases of severe deficiency, adults may develop osteomalacia, whereas children may be affected by rickets disease.
  3. Therapeutic doses of specific vitamin D analogs are used in the treatment of chronic hypocalcemia, hypophosphatemia, rickets, and osteodystrophy associated with various medical conditions including chronic renal failure, familial hypophosphatemia, and hypoparathyroidism (postsurgical or idiopathic, or pseudohypoparathyroidism). Some analogs have been found to reduct elevated parathyroid hormone concentrations in patients with renal osteodystrophy associated with hyperparathyroidism. Theoretically, any of the vitamin D analogs may be used for the above conditions, However, because of their pharmacologic properties, some may be more useful in certain situations than others..
  4. Alfacalcidol, calcitriol, and dihydrotachysterol are usually preferred in patients with renal failure since these patients have impaired ability to synthesize calcitriol from cholecalciferol and ergocalciferol; therefore, the response is more predictable. In addition, their shorter half-lives may make toxicity easier to manage (hypercalcemia reverses more quickly). Ergocalciferol may not be the preferred agent in the treatment of familial hypophosphatemia or hypoparathyroidism because the large doses needed are associated with a risk of overdose and hypercalcemia; dihydrotachysterol and calcitriol may be preferred. /Included in US product labeling.
  5. The presence of bile is required for absorption of ergocalciferol and the extent of GI absorption may be decreased in patients with hepatic, biliary, or GI disease (e.g., Crohn’s disease, Whipple’s disease, sprue). Because vitamin D is fat soluble, it is incorporated into chylomicrons and absorbed via the lymphatic system; approximately 80% of ingested vitamin D appears to be absorbed systemically through this mechanism, principally in the small intestine. Although some evidence suggested that intestinal absorption of vitamin D may be decreased in geriatric adults, other evidence did not show clinically important age-related alterations in GI absorption of the vitamin in therapeutic doses.
  6. A rare, inherited bone disorder marked by low levels of phosphate in the blood (familial hypophosphatemia). Taking specific forms of vitamin D, called calcitriol or dihydrotachysterol, by mouth along with phosphate supplements is effective for treating bone disorders in people with low levels of phosphate in the blood.
  7. Underactive parathyroid (hypoparathyroidism). Taking specific forms of vitamin D, called dihydrotachysterol, calcitriol, or ergocalciferol, by mouth is effective for increasing calcium blood levels in people with low parathyroid hormone levels.
  8. Softening of the bones (osteomalacia). Taking vitamin D3 by mouth is effective for treating this condition.
  9. A bone disorder that occurs in people with kidney disease (renal osteodystrophy). Taking a specific form of vitamin D, called calcitriol, by mouth helps to manage low calcium levels and prevent bone loss in people with kidney failure.
  10. Rickets. Taking vitamin D by mouth is effective for preventing and treating rickets. A specific form of vitamin D, called calcitriol, should be used in people with kidney failure.
  11. Vitamin D deficiency. Taking vitamin D by mouth is effective for preventing and treating vitamin D deficiency.
  12. Bone loss in people taking drugs called corticosteroids. Taking vitamin D by mouth prevents bone loss in people taking drugs called corticosteroids. Also, taking vitamin D alone or with calcium seems to improve bone density in people with existing bone loss caused by using corticosteroids.
  13. Weak and brittle bones (fracture risk. সহজ বাংলা: হাড় দুর্বল হয়ে ভাঙার ঝুঁকি বেশি।" data-rx-term="osteoporosis" data-rx-definition="Osteoporosis means weak, fragile bones with higher fracture risk. সহজ বাংলা: হাড় দুর্বল হয়ে ভাঙার ঝুঁকি বেশি।">osteoporosis). Taking vitamin D3 by mouth along with calcium seems to help prevent bone loss and bone breaks in people with osteoporosis.
  14. Psoriasis. Applying vitamin D in the form of calcitriol, calcipotriene, maxacalcitol, or paricalcitol to the skin can help treat plaque-type psoriasis. Applying vitamin D along with corticosteroids seems to work better than applying vitamin D or corticosteroids alone. But taking vitamin D by mouth doesn’t seem to help.
  15. Hay fever. Taking vitamin D by mouth seems to reduce symptoms of hay fever in adults and children. But it isn’t clear if taking vitamin D during pregnancy can help to prevent hay fever in the child after birth.
  16. Cavities. Taking vitamin D2 or D3 by mouth reduces the risk of cavities by 36% to 49% in infants, children, and adolescents.
  17. Heart failure. Taking vitamin D by mouth can help reduce the risk of developing heart failure in some people. But it doesn’t seem to help patients who already have heart failure
  18. Bone loss in people with overactive parathyroid (hyperparathyroidism-related bone loss). Taking vitamin D3 by mouth seems to reduce parathyroid hormone levels and bone loss in people with a condition called hyperparathyroidism.
  19. Infection of the airways. Taking vitamin D by mouth helps prevent respiratory infections in children. But taking vitamin D by mouth during pregnancy doesn’t seem to reduce the risk of these infections in the child after birth. It also doesn’t help prevent infections in adults
  20. Preventing tooth loss (tooth retention). Taking calcium and vitamin D3 by mouth appears to prevent tooth loss in elderly people.

Most people in the world meet at least some of their vitamin D needs through exposure to sunlight [rx]. Type B UV (UVB) radiation with a wavelength of approximately 290–320 nanometers penetrates uncovered skin and converts cutaneous 7-dehydrocholesterol to previtamin D3, which in turn becomes vitamin D3. Season, time of day, length of day, cloud cover, smog, skin melanin content, and sunscreen are among the factors that affect UV radiation exposure and vitamin D synthesis. Older people and people with dark skin are less able to produce vitamin D from sunlight [rx]. UVB radiation does not penetrate glass, so exposure to sunshine indoors through a window does not produce vitamin D [rx].

The factors that affect UV radiation exposure, individual responsiveness, and uncertainties about the amount of sun exposure needed to maintain adequate vitamin D levels make it difficult to provide guidelines on how much sun exposure is required for sufficient vitamin D synthesis [rx,rx]. Some expert bodies and vitamin D researchers suggest, for example, that approximately 5–30 minutes of sun exposure, particularly between 10 a.m. and 4 p.m., either daily or at least twice a week to the face, arms, hands, and legs without sunscreen usually leads to sufficient vitamin D synthesis [rx,rx,rx]. Moderate use of commercial tanning beds that emit 2% to 6% UVB radiation is also effective [rx,rx].

Contraindications

  • There is no known contraindication although oo much vitamin D can cause harmful high calcium levels.
  • Tell your doctor right away if any of these signs of high vitamin D/calcium levels occur: nausea/vomiting, constipation, loss of appetite, increased thirst, increased urination, mental/mood changes, unusual tiredness.

Dosages

Strength

Applies to the following strengths: 10 mcg/mL; 50 mcg; 25 mcg; 10 mcg; 125 mcg; 1250 mcg; 350 mcg; 250 mcg/mL; 100 mcg; 37.5 mcg; 125 mcg/mL; 250 mcg; 125 mcg/0.5 mL; 10 mcg/drop; 25 mcg/drop; 10 mcg/0.25 mL (400 intl units/0.25 mL); 325 mcg; 625 mcg; 25 mcg/10 mL; 62.5 mcg (0.0625 mg)

Normal combined (ie, 25-hydroxyvitamin D) plasma concentrations of 25-hydroxycholecalciferol (calcifediol) and 25-hydroxyergocalciferol, which are the major circulating metabolites of cholecalciferol and ergocalciferol, have been reported to range from 8-80 ng/mL, depending on the assay used, and vary with exposure to UV light. A commonly reported range for the lower limit of normal is 8-15 ng/mL, depending on geographic location (eg, Southern California would be higher than Massachusetts).

Usual Adult Dose for Vitamin/Mineral Supplementation

US Recommended Dietary Allowance (RDA) for vitamin D:

  • 18 to 70 years: 15 mcg (600 international units) daily
  • Tolerable Upper Intake Level: 100 mcg (4000 international units)

Usual Geriatric Dose for Vitamin/Mineral Supplementation

US Recommended Dietary Allowance (RDA) for vitamin D:

  • 70 years and older: 20 mcg (800 international units) daily
  • Tolerable Upper Intake Level: 100 mcg (4000 international units)

Usual Pediatric Dose for Vitamin/Mineral Supplementation

US Recommended Dietary Allowance (RDA) for vitamin D:

  • 0 to 6 months: 10 mcg (400 international units) daily
  • Tolerable Upper Intake Level (UL): 25 mcg (1000 international units)
  • 7 to 12 months: 10 mcg (400 international units) daily
  • UL: 38 mcg (1500 international units)
  • 1 to 3 years: 15 mcg (600 international units) daily
  • UL: 63 mcg (2500 international units)
  • 4 to 8 years: 15 mcg (600 international units) daily
  • UL: 75 mcg (3000 international units)
  • 9 to 18 years: 15 mcg (600 international units) daily
  • UL: 100 mcg (4000 international units)

Side Effects

The Most Common

  • loss of appetite
  • weight loss
  • nausea
  • vomiting
  • constipation
  • loss of appetite
  • weight loss
  • nausea
  • vomiting
  • constipation
  • weakness

Rare

  • cough
  • difficulty swallowing
  • dizziness
  • fast heartbeat
  • hives or itching
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • skin rash
  • tightness in the chest
  • unusual tiredness or weakness

Cholecalciferol (vitamin D3) may cause other side effects. Call your doctor if you have any unusual problems while taking this vitamin.

Drug Interactions

Pregnancy and Lactation

FDA Pregnancy Category : C

Pregnancy

No data are available for cholecalciferol (vitamin D3). Administration of high doses (≥10,000 IU/every
other day) of ergocalciferol (vitamin D2) to pregnant rabbits resulted in abortions and an increased
incidence of fetal aortic stenosis. Administration of vitamin D2 (40,000 IU/day) to pregnant rats resulted in
neonatal death, decreased fetal weight, and impaired osteogenesis of long bones postnatally.
There are no studies in pregnant women. FOSAMAX PLUS D should be used during pregnancy only if
the potential benefit justifies the potential risk to the mother and fetus.

Nursing Mothers

Cholecalciferol and some of its active metabolites pass into breast milk. It is not known whether
alendronate is excreted in human milk. Because many drugs are excreted in human milk, caution should
be exercised when FOSAMAX PLUS D is administered to nursing women.

Warning

Excess amounts of vitamin D are toxic. Because vitamin D increases calcium absorption in the gastrointestinal tract, vitamin D toxicity results in marked hypercalcemia (total calcium greater than 11.1 mg/dL, beyond the normal range of 8.4 to 10.2 mg/dL), hypercalciuria, and high serum 25(OH)D levels (typically greater than 375 nmol/l [150 ng/mL]) [1rx]. Hypercalcemia, in turn, can lead to nausea, vomiting, muscle weakness, neuropsychiatric disturbances, pain, loss of appetite, dehydration, polyuria, excessive thirst, and kidney stones.

In extreme cases, vitamin D toxicity causes renal failure, calcification of soft tissues throughout the body (including in coronary vessels and heart valves), cardiac arrhythmias, and even death. Vitamin D toxicity has been caused by consumption of dietary supplements that contained excessive vitamin D amounts because of manufacturing errors, that were taken inappropriately or in excessive amounts, or that were incorrectly prescribed by physicians, [rx-rx].

Experts do not believe that excessive sun exposure results in vitamin D toxicity because thermal activation of previtamin D3 in the skin gives rise to various non-vitamin D forms that limit formation of vitamin D3. Some vitamin D3 is also converted to nonactive forms [rx]. However, frequent use of tanning beds, which provide artificial UV radiation, can lead to 25(OH)D levels well above 375–500 nmol/L (150–200 ng/mL) [rx-rx].

The combination of high intakes of calcium (about 2,100 mg/day from food and supplements) with moderate amounts of vitamin D (about 19 mcg [765 IU]/day from food and supplements) increased the risk of kidney stones by 17% over 7 years among 36,282 postmenopausal women who were randomly assigned to take 1,000 mg/day calcium and 10 mcg (400 IU)/day vitamin D or a placebo [rx]. However, other, shorter (from 24 weeks to 5 years) clinical trials of vitamin D supplementation alone or with calcium in adults found greater risks of hypercalcemia and hypercalciuria, but not of kidney stones [rx,rx].

The FNB established ULs for vitamin D in 2010 (Table 4) [1]. While acknowledging that signs and symptoms of toxicity are unlikely at daily intakes below 250 mcg (10,000 IU), the FNB noted that even vitamin D intakes lower than the ULs might have adverse health effects over time. The FNB recommended avoiding serum 25(OH)D levels above approximately 125–150 nmol/L (50–60 ng/mL), and it found that even lower serum levels (approximately 75–120 nmol/L [30–48 ng/mL]) are associated with increases in rates of all-cause mortality, risk of cancer at some sites (e.g., pancreas), risk of cardiovascular events, and number of falls and fractures among older adults.

Table 4: Tolerable Upper Intake Levels (ULs) for Vitamin D [1]
AgeMaleFemalePregnancyLactation
0–6 months25 mcg (1,000 IU)25 mcg (1,000 IU)
7–12 months38 mcg (1,500 IU)38 mcg (1,500 IU)
1–3 years63 mcg (2,500 IU)63 mcg (2,500 IU)
4–8 years75 mcg (3,000 IU)75 mcg (3,000 IU)
9–18 years100 mcg (4,000 IU)100 mcg (4,000 IU)100 mcg (4,000 IU)100 mcg (4,000 IU)
19+ years100 mcg (4,000 IU)100 mcg (4,000 IU)100 mcg (4,000 IU)100 mcg (4,000 IU)

How should this medicine be used?

Cholecalciferol (vitamin D3) comes as a capsule, gel capsule, chewable gel (gummy), tablet, and liquid drops to take by mouth. It is usually taken once or twice daily depending on the preparation, your age, and your medical condition(s). Cholecalciferol is available without a prescription, but your doctor may prescribe cholecalciferol to treat certain conditions. Check with your doctor or pharmacist before taking a cholecalciferol (vitamin D) supplement. Take cholecalciferol at around the same time every day. Follow the directions on your product label or doctor’s instructions carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take cholecalciferol exactly as directed. Do not take more or less of it or take it more often than recommended by your doctor.

Cholecalciferol liquid drops may be added to your child’s food or drink.

Cholecalciferol supplements are available alone and in combination with vitamins, and in combination with medications.

What special precautions should I follow?

Before taking cholecalciferol,

  • tell your doctor and pharmacist if you are allergic to cholecalciferol, any other medications, or any of the ingredients in cholecalciferol products. Ask your pharmacist for a list of the ingredients.
  • tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take while taking cholecalciferol. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
  • tell your doctor if you have or have ever had hyperparathyroidism (a condition in which the body produces too much parathyroid hormone [PTH; a natural substance needed to control the amount of calcium in the blood]), kidney disease, or have high blood levels of calcium.
  • tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking cholecalciferol (vitamin D3), call your doctor.

What special dietary instructions should I follow?

When cholecalciferol (vitamin D3) is used to treat and prevent bone diseases, you should eat and drink of foods and drinks that are rich in calcium. If you find it difficult to eat enough calcium-rich foods, tell your doctor. In that case, your doctor can prescribe or recommend a calcium supplement.

Unless your doctor tells you otherwise, continue your normal diet.

What should I do if I forget a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

Doctor visit helper

Prepare before seeing a doctor

A simple rural-patient checklist to help you explain symptoms clearly, ask better questions, and avoid unsafe self-treatment.

Safety note: This is not a prescription or diagnosis. For severe symptoms, pregnancy danger signs, children with serious illness, chest pain, breathing difficulty, stroke-like weakness, or major injury, seek urgent care.

Which doctor may help?

Start with a registered doctor or the nearest qualified health center.

What to tell the doctor

  • Write when the problem started and how it changed.
  • Bring old prescriptions, investigation reports, and current medicines.
  • Write allergies, pregnancy status, diabetes, kidney/liver disease, and major past illnesses.
  • Bring one family member if the patient is weak, elderly, confused, or a child.

Questions to ask

  • What is the most likely cause of my symptoms?
  • Which danger signs mean I should go to hospital quickly?
  • Which tests are necessary now, and which can wait?
  • How should I take medicines safely and what side effects should I watch for?
  • When should I come for follow-up?

Tests to discuss

  • Vital signs: temperature, pulse, blood pressure, oxygen saturation
  • Basic physical examination by a clinician
  • CBC, urine test, blood sugar, or imaging only when clinically needed

Avoid these mistakes

  • Do not use antibiotics, steroid tablets/injections, or strong painkillers without proper medical advice.
  • Do not hide pregnancy, kidney disease, ulcer, allergy, or blood thinner use.
  • Do not delay emergency care when danger signs are present.

Medicine safety and first-aid guide

This section is for patient education only. It does not replace a doctor, pharmacist, or emergency care.

Safe first steps

  • Avoid heavy lifting, sudden bending, and prolonged bed rest.
  • Use comfortable posture and gentle movement as tolerated.
  • Discuss physiotherapy, X-ray, or MRI only when clinically needed.

OTC medicine safety

  • For mild back pain, pain-relief medicine may be discussed with a doctor or pharmacist.
  • Avoid repeated painkiller use if you have kidney disease, stomach ulcer, uncontrolled blood pressure, or are taking blood thinners.

Avoid these mistakes

  • Do not start antibiotics without a proper medical decision.
  • Do not use steroid tablets or injections casually for quick relief.
  • Do not delay emergency care because of home remedies.

Get urgent help if

  • Back pain with leg weakness, numbness around private area, loss of urine/stool control, fever, cancer history, or major injury needs urgent care.
Medicine names, dose, and timing must be decided by a qualified clinician or pharmacist after checking age, pregnancy, allergy, other diseases, and current medicines.

For rural patients and family caregivers

Patient health record and symptom diary

Write your symptoms, medicines already taken, test results, and questions before visiting a doctor. This note stays on your device unless you print or copy it.

Doctor to discuss: Medicine doctor / pediatrician for children / qualified clinician
Tests to discuss with doctor
  • Temperature chart and hydration assessment
  • CBC with platelet count if fever persists or dengue/other infection is possible
  • Urine test, malaria/dengue tests, chest evaluation, or blood culture only when clinically indicated
Questions to ask
  • What is the most likely cause of my symptoms?
  • Which warning signs mean I should go to emergency care?
  • Which tests are really needed now?
  • Which medicines are safe for my age, pregnancy status, allergy, kidney/liver/stomach condition, and current medicines?
  • Do I need antibiotics, or is this more likely viral?

Emergency warning signs such as chest pain, severe breathing difficulty, sudden weakness, confusion, severe dehydration, major injury, or loss of bladder/bowel control need urgent medical care. Do not wait for online information.

Safe pathway to proper treatment

Care roadmap for: Vitamin D3 – Uses, Dosage, Side Effects, Interactions

Use this simple roadmap to understand the next safe steps. It is educational and does not replace examination by a doctor.

Go to emergency care if you notice:
  • Severe or rapidly worsening symptoms
  • Breathing difficulty, chest pain, fainting, confusion, severe weakness, major injury, or severe dehydration
Doctor / service to discuss: Qualified healthcare provider; specialist depends on symptoms and examination.
  1. Step 1

    Check danger signs first

    If danger signs are present, seek emergency care and do not wait for online information.

  2. Step 2

    Record the symptom story

    Write when symptoms started, severity, medicines already taken, allergies, pregnancy status, and test results.

  3. Step 3

    Visit a qualified clinician

    A doctor, nurse, or qualified healthcare provider can examine you and decide which tests or treatment are needed.

  4. Step 4

    Do only useful tests

    Do tests after clinical assessment. Avoid unnecessary tests, random antibiotics, or repeated medicines without diagnosis.

  5. Step 5

    Follow up and return early if worse

    If symptoms worsen, new warning signs appear, or treatment is not helping, return for review quickly.

Rural patient practical tips
  • Take a written symptom diary and all previous prescriptions/test reports.
  • Do not hide medicines already taken, even herbal or over-the-counter medicines.
  • Ask which warning signs mean urgent referral to hospital.

This roadmap is for education. A real diagnosis and treatment plan requires history, examination, and clinical judgment.

RX Patient Help

Ask a health question safely

Write your symptom story. A health professional or site editor can review it before any answer is prepared. This box is not for emergency care.

Emergency first: Severe chest pain, breathing trouble, unconsciousness, stroke signs, severe injury, heavy bleeding, or rapidly worsening symptoms need urgent local medical care now.

Frequently Asked Questions

Mechanism of ActionMost individuals naturally generate adequate amounts of vitamin D through ordinary dietary intake of vitamin D (in some foods like eggs, fish, and cheese) and natural photochemical conversion of the vitamin D3 precursor 7-dehydrocholesterol in the skin via exposure to sunlight. Conversely, vitamin D deficiency can often occur from a combination of insufficient exposure to sunlight, inadequate dietary intake of vitamin D, genetic defects with endogenous vitamin D receptor, or even severe liver or kidney disease. Such deficiency is known for resulting in conditions like rickets or osteomalacia, all of which reflect inadequate mineralization of bone, enhanced compensatory skeletal demineralization, resultant decreased calcium ion blood concentrations, and increases in the production and secretion of parathyroid hormone. Increases in parathyroid hormone stimulate the mobilization of skeletal calcium and the renal excretion of phosphorus. This enhanced mobilization of skeletal calcium leads towards porotic bone conditions. Ordinarily, while vitamin D3 is made naturally via photochemical processes in the skin, both itself and vitamin D2 can be found in various food and pharmaceutical sources as dietary supplements. The principal biological function of vitamin D is the maintenance of normal levels of serum calcium and phosphorus in the bloodstream by enhancing the efficacy of the small intestine to absorb these minerals from the diet. At the liver, vitamin D3 or D2 is hydroxylated to 25-hydroxyvitamin D and then finally to the primary active metabolite 1,25-dihydroxyvitamin D in the kidney via further hydroxylation. This final metabolite binds to endogenous vitamin d receptors, which results in a variety of regulatory roles - including maintaining calcium balance, the regulation of parathyroid hormone, the promotion of the renal reabsorption of calcium, increased intestinal absorption of calcium and phosphorus, and increased calcium and phosphorus mobilization of calcium and phosphorus from bone to plasma to maintain balanced levels of each in bone and the plasma. In particular, calcitriol interacts with vitamin D receptors in the small intestine to enhance the efficiency of intestinal calcium and phosphorous absorption from about 10-15% to 30-40% and 60% increased to 80%, respectively. Furthermore, calcitriol binds with vitamin D receptors in osteoblasts to stimulate a receptor activator of nuclear factor kB ligand (or RANKL) which subsequently interacts with receptor activator of nuclear factor kB (NFkB) on immature preosteoclasts, causing them to become mature bone-resorbing osteoclasts. Such mature osteoclasts ultimately function in removing calcium and phosphorus from bone to maintain blood calcium and phosphorus levels. Moreover, calcitriol also stimulates calcium reabsorption from the glomerular filtrate in the kidneys. Additionally, it is believed that when calcitriol binds with nuclear vitamin D receptors, that this bound complex itself binds to retinoic acid X receptor (RXR) to generate a heterodimeric complex that consequently binds to specific nucleotide sequences in the DNA called vitamin D response elements. When bound, various transcription factors attach to this complex, resulting in either up or down-regulation of the associated gene's activity. It is thought that there may be as much as 200 to 2000 genes that possess vitamin D response elements or that are influenced indirectly to control a multitude of genes across the genome. It is in this way that cholecalciferol is believed to function in regulating gene transcription associated with cancer risk, autoimmune disorders, and cardiovascular disease linked to vitamin D deficiency. In fact, there has been some research to suggest calcitriol may also be able to prevent malignancies by inducing cellular maturation and inducing apoptosis and inhibiting angiogenesis, exhibit anti-inflammatory effects by inhibiting foam cell formation and promoting angiogenesis in endothelial colony-forming cells in vitro, inhibit immune reactions by enhancing the transcription of endogenous antibiotics like cathelicidin and regulate the activity and differentiation of CD4+ T cells, amongst a variety of other proposed actions.The principal biologic function of vitamin D is to maintain serum calcium and phosphorus concentrations within the normal range by enhancing the efficiency of the small intestine to absorb these minerals from the diet. Calcitriol (activated vitamin D) enhances the efficiency of intestinal calcium absorption along the entire small intestine, but principally in the duodenum and jejunum. Calcitriol also enhances phosphorus absorption along the entire small intestine, but principally in the jejunum and ileum. The activated forms of ergocalciferol, doxercalciferol, and cholecalciferol may have a negative feedback effect on parathyroid hormone (PTH) production.PharmacodynamicsThe in vivo synthesis of the predominant two biologically active metabolites of vitamin D occurs in two steps. The first hydroxylation of vitamin D3 cholecalciferol (or D2) occurs in the liver to yield 25-hydroxyvitamin D while the second hydroxylation happens in the kidneys to give 1, 25-dihydroxyvitamin D. These vitamin D metabolites subsequently facilitate the active absorption of calcium and phosphorus in the small intestine, serving to increase serum calcium and phosphate levels sufficiently to allow bone mineralization. Conversely, these vitamin D metabolites also assist in mobilizing calcium and phosphate from bone and likely increase the reabsorption of calcium and perhaps also of phosphate via the renal tubules. There exists a period of 10 to 24 hours between the administration of cholecalciferol and the initiation of its action in the body due to the necessity of synthesis of the active vitamin D metabolites in the liver and kidneys. It is parathyroid hormone that is responsible for the regulation of such metabolism at the level of the kidneys.Metabolic activation of cholecalciferol and ergocalciferol occurs in 2 steps, the first in the liver and the second in the kidneys. Metabolic activation of calcifediol occurs in the kidneys; dihydrotachysterol, alfacalcidol and doxercalciferol are activated in the liver.IndicationsCholecalciferol use is indicated for the treatment of specific medical conditions like refractory rickets (or vitamin D resistant rickets), hypoparathyroidism, and familial hypophosphatemia. Concurrently, as one of the most commonly utilized forms of vitamin D, cholecalciferol is also very frequently used as a supplement in individuals to maintain sufficient vitamin d levels in the body or to treat vitamin D deficiency, as well as various medical conditions that can be associated directly or indirectly with vitamin d insufficiency like osteoporosis and chronic kidney disease, among others. Vitamin D insufficiency and deficiency are prevalent worldwide; thus, regular monitoring of vitamin D levels is recommended for individuals at risk of insufficiency and deficiency. Vitamin D deficiency is associated with an increased risk of cardiovascular disease, type 2 diabetes, cancer, depression, and cognitive impairment. Individuals experiencing mild vitamin D deficiency may exhibit symptoms such as fatigue, joint pains, and depression. In cases of severe deficiency, adults may develop osteomalacia, whereas children may be affected by rickets disease. Therapeutic doses of specific vitamin D analogs are used in the treatment of chronic hypocalcemia, hypophosphatemia, rickets, and osteodystrophy associated with various medical conditions including chronic renal failure, familial hypophosphatemia, and hypoparathyroidism (postsurgical or idiopathic, or pseudohypoparathyroidism). Some analogs have been found to reduct elevated parathyroid hormone concentrations in patients with renal osteodystrophy associated with hyperparathyroidism. Theoretically, any of the vitamin D analogs may be used for the above conditions, However, because of their pharmacologic properties, some may be more useful in certain situations than others.. Alfacalcidol, calcitriol, and dihydrotachysterol are usually preferred in patients with renal failure since these patients have impaired ability to synthesize calcitriol from cholecalciferol and ergocalciferol; therefore, the response is more predictable. In addition, their shorter half-lives may make toxicity easier to manage (hypercalcemia reverses more quickly). Ergocalciferol may not be the preferred agent in the treatment of familial hypophosphatemia or hypoparathyroidism because the large doses needed are associated with a risk of overdose and hypercalcemia; dihydrotachysterol and calcitriol may be preferred. /Included in US product labeling. The presence of bile is required for absorption of ergocalciferol and the extent of GI absorption may be decreased in patients with hepatic, biliary, or GI disease (e.g., Crohn's disease, Whipple's disease, sprue). Because vitamin D is fat soluble, it is incorporated into chylomicrons and absorbed via the lymphatic system; approximately 80% of ingested vitamin D appears to be absorbed systemically through this mechanism, principally in the small intestine. Although some evidence suggested that intestinal absorption of vitamin D may be decreased in geriatric adults, other evidence did not show clinically important age-related alterations in GI absorption of the vitamin in therapeutic doses. A rare, inherited bone disorder marked by low levels of phosphate in the blood (familial hypophosphatemia). Taking specific forms of vitamin D, called calcitriol or dihydrotachysterol, by mouth along with phosphate supplements is effective for treating bone disorders in people with low levels of phosphate in the blood. Underactive parathyroid (hypoparathyroidism). Taking specific forms of vitamin D, called dihydrotachysterol, calcitriol, or ergocalciferol, by mouth is effective for increasing calcium blood levels in people with low parathyroid hormone levels. Softening of the bones (osteomalacia). Taking vitamin D3 by mouth is effective for treating this condition. A bone disorder that occurs in people with kidney disease (renal osteodystrophy). Taking a specific form of vitamin D, called calcitriol, by mouth helps to manage low calcium levels and prevent bone loss in people with kidney failure. Rickets. Taking vitamin D by mouth is effective for preventing and treating rickets. A specific form of vitamin D, called calcitriol, should be used in people with kidney failure. Vitamin D deficiency. Taking vitamin D by mouth is effective for preventing and treating vitamin D deficiency. Bone loss in people taking drugs called corticosteroids. Taking vitamin D by mouth prevents bone loss in people taking drugs called corticosteroids. Also, taking vitamin D alone or with calcium seems to improve bone density in people with existing bone loss caused by using corticosteroids. Weak and brittle bones (osteoporosis). Taking vitamin D3 by mouth along with calcium seems to help prevent bone loss and bone breaks in people with osteoporosis. Psoriasis. Applying vitamin D in the form of calcitriol, calcipotriene, maxacalcitol, or paricalcitol to the skin can help treat plaque-type psoriasis. Applying vitamin D along with corticosteroids seems to work better than applying vitamin D or corticosteroids alone. But taking vitamin D by mouth doesn't seem to help. Hay fever. Taking vitamin D by mouth seems to reduce symptoms of hay fever in adults and children. But it isn't clear if taking vitamin D during pregnancy can help to prevent hay fever in the child after birth. Cavities. Taking vitamin D2 or D3 by mouth reduces the risk of cavities by 36% to 49% in infants, children, and adolescents. Heart failure. Taking vitamin D by mouth can help reduce the risk of developing heart failure in some people. But it doesn't seem to help patients who already have heart failure Bone loss in people with overactive parathyroid (hyperparathyroidism-related bone loss). Taking vitamin D3 by mouth seems to reduce parathyroid hormone levels and bone loss in people with a condition called hyperparathyroidism. Infection of the airways. Taking vitamin D by mouth helps prevent respiratory infections in children. But taking vitamin D by mouth during pregnancy doesn't seem to reduce the risk of these infections in the child after birth. It also doesn't help prevent infections in adults Preventing tooth loss (tooth retention). Taking calcium and vitamin D3 by mouth appears to prevent tooth loss in elderly people.Sun exposureMost people in the world meet at least some of their vitamin D needs through exposure to sunlight [rx]. Type B UV (UVB) radiation with a wavelength of approximately 290–320 nanometers penetrates uncovered skin and converts cutaneous 7-dehydrocholesterol to previtamin D3, which in turn becomes vitamin D3. Season, time of day, length of day, cloud cover, smog, skin melanin content, and sunscreen are among the factors that affect UV radiation exposure and vitamin D synthesis. Older people and people with dark skin are less able to produce vitamin D from sunlight [rx]. UVB radiation does not penetrate glass, so exposure to sunshine indoors through a window does not produce vitamin D [rx].The factors that affect UV radiation exposure, individual responsiveness, and uncertainties about the amount of sun exposure needed to maintain adequate vitamin D levels make it difficult to provide guidelines on how much sun exposure is required for sufficient vitamin D synthesis [rx,rx]. Some expert bodies and vitamin D researchers suggest, for example, that approximately 5–30 minutes of sun exposure, particularly between 10 a.m. and 4 p.m., either daily or at least twice a week to the face, arms, hands, and legs without sunscreen usually leads to sufficient vitamin D synthesis [rx,rx,rx]. Moderate use of commercial tanning beds that emit 2% to 6% UVB radiation is also effective [rx,rx]. ContraindicationsThere is no known contraindication although oo much vitamin D can cause harmful high calcium levels. Tell your doctor right away if any of these signs of high vitamin D/calcium levels occur: nausea/vomiting, constipation, loss of appetite, increased thirst, increased urination, mental/mood changes, unusual tiredness.Dosages Strength Applies to the following strengths: 10 mcg/mL; 50 mcg; 25 mcg; 10 mcg; 125 mcg; 1250 mcg; 350 mcg; 250 mcg/mL; 100 mcg; 37.5 mcg; 125 mcg/mL; 250 mcg; 125 mcg/0.5 mL; 10 mcg/drop; 25 mcg/drop; 10 mcg/0.25 mL (400 intl units/0.25 mL); 325 mcg; 625 mcg; 25 mcg/10 mL; 62.5 mcg (0.0625 mg) Normal combined (ie, 25-hydroxyvitamin D) plasma concentrations of 25-hydroxycholecalciferol (calcifediol) and 25-hydroxyergocalciferol, which are the major circulating metabolites of cholecalciferol and ergocalciferol, have been reported to range from 8-80 ng/mL, depending on the assay used, and vary with exposure to UV light. A commonly reported range for the lower limit of normal is 8-15 ng/mL, depending on geographic location (eg, Southern California would be higher than Massachusetts). Usual Adult Dose for Vitamin/Mineral Supplementation US Recommended Dietary Allowance (RDA) for vitamin D:18 to 70 years: 15 mcg (600 international units) daily Tolerable Upper Intake Level: 100 mcg (4000 international units)Usual Geriatric Dose for Vitamin/Mineral Supplementation US Recommended Dietary Allowance (RDA) for vitamin D:70 years and older: 20 mcg (800 international units) daily Tolerable Upper Intake Level: 100 mcg (4000 international units)Usual Pediatric Dose for Vitamin/Mineral Supplementation US Recommended Dietary Allowance (RDA) for vitamin D:0 to 6 months: 10 mcg (400 international units) daily Tolerable Upper Intake Level (UL): 25 mcg (1000 international units) 7 to 12 months: 10 mcg (400 international units) daily UL: 38 mcg (1500 international units) 1 to 3 years: 15 mcg (600 international units) daily UL: 63 mcg (2500 international units) 4 to 8 years: 15 mcg (600 international units) daily UL: 75 mcg (3000 international units) 9 to 18 years: 15 mcg (600 international units) daily UL: 100 mcg (4000 international units)Side Effects The Most Commonloss of appetite weight loss nausea vomiting constipation loss of appetite weight loss nausea vomiting constipation weaknessRarecough difficulty swallowing dizziness fast heartbeat hives or itching puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue skin rash tightness in the chest unusual tiredness or weaknessCholecalciferol (vitamin D3) may cause other side effects. Call your doctor if you have any unusual problems while taking this vitamin.Drug InteractionsDrug InteractionAbametapir The serum concentration of Cholecalciferol can be increased when it is combined with Abametapir.Acebutolol The metabolism of Acebutolol can be decreased when combined with Cholecalciferol.Acetaminophen The metabolism of Acetaminophen can be decreased when combined with Cholecalciferol.Acetyldigitoxin The risk or severity of ventricular arrhythmias and Cardiac Arrhythmia can be increased when Cholecalciferol is combined with Acetyldigitoxin.Alfacalcidol The risk or severity of adverse effects can be increased when Cholecalciferol is combined with Alfacalcidol.Almotriptan The metabolism of Almotriptan can be decreased when combined with Cholecalciferol.Alogliptin The metabolism of Alogliptin can be decreased when combined with Cholecalciferol.Alprenolol The metabolism of Alprenolol can be decreased when combined with Cholecalciferol.Aluminum hydr The serum concentration of Aluminum hydroxide can be increased when it is combined with Cholecalciferol.Aminophenazone The metabolism of Aminophenazone can be decreased when combined with Cholecalciferol.Amiodarone The metabolism of Cholecalciferol can be decreased when combined with Amiodarone.Amitriptyline The metabolism of Amitriptyline can be decreased when combined with Cholecalciferol.Amoxapine The metabolism of Amoxapine can be decreased when combined with Cholecalciferol.Amphetamine The metabolism of Amphetamine can be decreased when combined with Cholecalciferol.Amprenavir The metabolism of Cholecalciferol can be decreased when combined with Amprenavir.Antipyrine The metabolism of Antipyrine can be decreased when combined with Cholecalciferol.Apalutamide The serum concentration of Cholecalciferol can be decreased when it is combined with Apalutamide.Aprepitant The metabolism of Cholecalciferol can be decreased when combined with Aprepitant.Arformoterol The metabolism of Arformoterol can be decreased when combined with Cholecalciferol.Aripiprazole The metabolism of Aripiprazole can be decreased when combined with Cholecalciferol.Aripiprazole lauroxil The metabolism of Aripiprazole lauroxil can be decreased when combined with Cholecalciferol.Astemizole The metabolism of Astemizole can be decreased when combined with Cholecalciferol.Asunaprevir The metabolism of Asunaprevir can be decreased when combined with Cholecalciferol.Atazanavir The metabolism of Cholecalciferol can be decreased when combined with Atazanavir.Atenolol The metabolism of Atenolol can be decreased when combined with Cholecalciferol.Atomoxetine The metabolism of Atomoxetine can be decreased when combined with Cholecalciferol.Avanafil The serum concentration of Avanafil can be increased when it is combined with Cholecalciferol.Azelastine The metabolism of Azelastine can be decreased when combined with Cholecalciferol.Beclomethasone dip The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Beclomethasone dipropionate.Bendroflumethiazide The risk or severity of hypercalcemia can be increased when Bendroflumethiazide is combined with Cholecalciferol.Benzatropine The metabolism of Benzatropine can be decreased when combined with Cholecalciferol.Benzthiazide The risk or severity of hypercalcemia can be increased when Benzthiazide is combined with Cholecalciferol.Benzyl alcohol The metabolism of Benzyl alcohol can be decreased when combined with Cholecalciferol.Bepridil The metabolism of Bepridil can be decreased when combined with Cholecalciferol.Berotralstat The metabolism of Cholecalciferol can be decreased when combined with Berotralstat.Betamethasone The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Betamethasone.Betamethasone The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Betamethasone phosphate.Betaxolol The metabolism of Betaxolol can be decreased when combined with Cholecalciferol.Boceprevir The metabolism of Cholecalciferol can be decreased when combined with Boceprevir.Bortezomib The metabolism of Bortezomib can be decreased when combined with Cholecalciferol.Brexpiprazole The metabolism of Brexpiprazole can be decreased when combined with Cholecalciferol.Budesonide The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Budesonide.Bupivacaine The metabolism of Bupivacaine can be decreased when combined with Cholecalciferol.Buprenorphine The metabolism of Buprenorphine can be decreased when combined with Cholecalciferol.Buspirone The metabolism of Buspirone can be decreased when combined with Cholecalciferol.Calcifediol The risk or severity of adverse effects can be increased when Calcifediol is combined with Cholecalciferol.Calcitriol The risk or severity of adverse effects can be increased when Calcitriol is combined with Cholecalciferol.Calcium acetate The risk or severity of adverse effects can be increased when Cholecalciferol is combined with Calcium acetate.Calcium glubionate The risk or severity of adverse effects can be increased when Cholecalciferol is combined with Calcium glubionate anhydrous.Calcium glucohep The risk or severity of adverse effects can be increased when Cholecalciferol is combined with Calcium glucoheptonate.Calcium levulinate The risk or severity of adverse effects can be increased when Cholecalciferol is combined with Calcium levulinate.Calcium polycarbophil The risk or severity of adverse effects can be increased when Cholecalciferol is combined with Calcium polycarbophil.Carbamazepine The metabolism of Cholecalciferol can be increased when combined with Carbamazepine.Carvedilol The metabolism of Carvedilol can be decreased when combined with Cholecalciferol.Celecoxib The metabolism of Celecoxib can be decreased when combined with Cholecalciferol.Celiprolol The metabolism of Celiprolol can be decreased when combined with Cholecalciferol.Cenobamate The serum concentration of Cholecalciferol can be decreased when it is combined with Cenobamate.Cevimeline The metabolism of Cevimeline can be decreased when combined with Cholecalciferol.Chloroquine The metabolism of Chloroquine can be decreased when combined with Cholecalciferol.Chlorothiazide The risk or severity of hypercalcemia can be increased when Chlorothiazide is combined with Cholecalciferol.Chlorpheniramine The metabolism of Chlorpheniramine can be decreased when combined with Cholecalciferol.Chlorpromazine The metabolism of Chlorpromazine can be decreased when combined with Cholecalciferol.Chlorthalidone The risk or severity of hypokalemia can be increased when Cholecalciferol is combined with Chlorthalidone.Chlorzoxazone The metabolism of Chlorzoxazone can be decreased when combined with Cholecalciferol.Cholestyramine The serum concentration of Cholecalciferol can be decreased when it is combined with Cholestyramine.Ciclesonide The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Ciclesonide.Cilostazol The metabolism of Cilostazol can be decreased when combined with Cholecalciferol.Cinnarizine The metabolism of Cinnarizine can be decreased when combined with Cholecalciferol.Ciprofloxacin The metabolism of Cholecalciferol can be decreased when combined with Ciprofloxacin.Citalopram The metabolism of Citalopram can be decreased when combined with Cholecalciferol.Clarithromycin The metabolism of Cholecalciferol can be decreased when combined with Clarithromycin.Clevidipine The metabolism of Clevidipine can be decreased when combined with Cholecalciferol.Clobetasol propionate The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Clobetasol propionate.Clomipramine The metabolism of Clomipramine can be decreased when combined with Cholecalciferol.Clonidine The metabolism of Clonidine can be decreased when combined with Cholecalciferol.Clozapine The serum concentration of Clozapine can be increased when it is combined with Cholecalciferol.Codeine The metabolism of Codeine can be decreased when combined with Cholecalciferol.Colesevelam The serum concentration of Cholecalciferol can be decreased when it is combined with Colesevelam.Colestipol The serum concentration of Cholecalciferol can be decreased when it is combined with Colestipol.Conivaptan The metabolism of Cholecalciferol can be decreased when combined with Conivaptan.Corticotropin The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Corticotropin.Corticotropin zinc The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Corticotropin zinc hydroxide.Cortisone acetate The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Cortisone acetate.Curcumin The metabolism of Cholecalciferol can be decreased when combined with Curcumin.Cyclopenthiazide The risk or severity of hypercalcemia can be increased when Cyclopenthiazide is combined with Cholecalciferol.Cyclosporine The metabolism of Cholecalciferol can be decreased when combined with Cyclosporine.Cyclothiazide The risk or severity of hypercalcemia can be increased when Cyclothiazide is combined with Cholecalciferol.Dabrafenib The serum concentration of Cholecalciferol can be decreased when it is combined with Dabrafenib.Dacomitinib The metabolism of Dacomitinib can be decreased when combined with Cholecalciferol.Danazol Danazol may increase the hypercalcemic activities of Cholecalciferol.Darifenacin The metabolism of Darifenacin can be decreased when combined with Cholecalciferol.Darunavir The metabolism of Cholecalciferol can be decreased when combined with Darunavir.Dasabuvir The metabolism of Dasabuvir can be decreased when combined with Cholecalciferol.Debrisoquine The metabolism of Debrisoquine can be decreased when combined with Cholecalciferol.Deflazacort The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Deflazacort.Delavirdine The metabolism of Cholecalciferol can be decreased when combined with Delavirdine.Desipramine The metabolism of Desipramine can be decreased when combined with Cholecalciferol.Deslanoside The risk or severity of ventricular arrhythmias and Cardiac Arrhythmia can be increased when Cholecalciferol is combined with Deslanoside.Desoximetasone The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Desoximetasone.Desvenlafaxine The metabolism of Cholecalciferol can be decreased when combined with Desvenlafaxine.Deutetrabenazine The metabolism of Deutetrabenazine can be decreased when combined with Cholecalciferol.Dexamethasone The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Dexamethasone.Dexamethasone The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Dexamethasone acetate.Dexchlorphenira The metabolism of Dexchlorpheniramine maleate can be decreased when combined with Cholecalciferol.Dexfenfluramine The metabolism of Dexfenfluramine can be decreased when combined with Cholecalciferol.Dextroamphetamine The metabolism of Dextroamphetamine can be decreased when combined with Cholecalciferol.Dextromethorphan The metabolism of Dextromethorphan can be decreased when combined with Cholecalciferol.Dextropropoxyphene The metabolism of Dextropropoxyphene can be decreased when combined with Cholecalciferol.Difluocortolone The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Difluocortolone.Digitoxin The risk or severity of ventricular arrhythmias and Cardiac Arrhythmia can be increased when Cholecalciferol is combined with Digitoxin.Digoxin The risk or severity of ventricular arrhythmias and Cardiac Arrhythmia can be increased when Cholecalciferol is combined with Digoxin.Dihydrocodeine The metabolism of Dihydrocodeine can be decreased when combined with Cholecalciferol.Dihydrotachysterol The risk or severity of adverse effects can be increased when Cholecalciferol is combined with Dihydrotachysterol.Diltiazem The metabolism of Diltiazem can be decreased when combined with Cholecalciferol.Diphenhydramine The metabolism of Diphenhydramine can be decreased when combined with Cholecalciferol.Dolasetron The metabolism of Dolasetron can be decreased when combined with Cholecalciferol.Domperidone The metabolism of Domperidone can be decreased when combined with Cholecalciferol.Donepezil The metabolism of Donepezil can be decreased when combined with Cholecalciferol.Doxazosin The metabolism of Doxazosin can be decreased when combined with Cholecalciferol.Doxepin The metabolism of Doxepin can be decreased when combined with Cholecalciferol.Doxercalciferol The risk or severity of adverse effects can be increased when Cholecalciferol is combined with Doxercalciferol.Doxorubicin The serum concentration of Doxorubicin can be increased when it is combined with Cholecalciferol.Dronedarone The metabolism of Cholecalciferol can be decreased when combined with Dronedarone.Duloxetine The metabolism of Duloxetine can be decreased when combined with Cholecalciferol.Efavirenz The metabolism of Cholecalciferol can be decreased when combined with Efavirenz.Elagolix The metabolism of Elagolix can be decreased when combined with Cholecalciferol.Eletriptan The metabolism of Eletriptan can be decreased when combined with Cholecalciferol.Eliglustat The metabolism of Eliglustat can be decreased when combined with Cholecalciferol.Elvitegravir The metabolism of Cholecalciferol can be decreased when combined with Elvitegravir.Enasidenib The metabolism of Enasidenib can be decreased when combined with Cholecalciferol.Encainide The metabolism of Encainide can be decreased when combined with Cholecalciferol.Encorafenib The metabolism of Encorafenib can be decreased when combined with Cholecalciferol.Enzalutamide The serum concentration of Cholecalciferol can be decreased when it is combined with Enzalutamide.Epcoritamab The serum concentration of Cholecalciferol can be increased when it is combined with Epcoritamab.Epinastine The metabolism of Epinastine can be decreased when combined with Cholecalciferol.Erdafitinib The risk or severity of adverse effects can be increased when Cholecalciferol is combined with Erdafitinib.Ergocalciferol The risk or severity of adverse effects can be increased when Ergocalciferol is combined with Cholecalciferol.Ergotamine The metabolism of Cholecalciferol can be decreased when combined with Ergotamine.Erlotinib The metabolism of Erlotinib can be decreased when combined with Cholecalciferol.Erythromycin The serum concentration of Cholecalciferol can be increased when it is combined with Erythromycin.Escitalopram The metabolism of Escitalopram can be decreased when combined with Cholecalciferol.Esmolol The metabolism of Esmolol can be decreased when combined with Cholecalciferol.Fedratinib The serum concentration of Cholecalciferol can be increased when it is combined with Fedratinib.Fenfluramine The metabolism of Fenfluramine can be decreased when combined with Cholecalciferol.Fesoterodine The metabolism of Fesoterodine can be decreased when combined with Cholecalciferol.Fexinidazole The metabolism of Fexinidazole can be decreased when combined with Cholecalciferol.Flecainide The metabolism of Flecainide can be decreased when combined with Cholecalciferol.Fluconazole The metabolism of Cholecalciferol can be decreased when combined with Fluconazole.Fludrocortisone The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Fludrocortisone.Flumethasone The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Flumethasone.Flunarizine The metabolism of Flunarizine can be decreased when combined with Cholecalciferol.Flunisolide The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Flunisolide.Fluocinolone ac The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Fluocinolone acetonide.Fluocinonide The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Fluocinonide.Fluocortolone The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Fluocortolone.Fluorometholone The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Fluorometholone.Fluoxetine The metabolism of Fluoxetine can be decreased when combined with Cholecalciferol.Fluprednisolone The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Fluprednisolone.Fluticasone The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Fluticasone.Fluticasone furoate The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Fluticasone furoate.Fluticasone propionate The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Fluticasone propionate.Fluvastatin The metabolism of Fluvastatin can be decreased when combined with Cholecalciferol.Fluvoxamine The metabolism of Fluvoxamine can be decreased when combined with Cholecalciferol.Formoterol The metabolism of Formoterol can be decreased when combined with Cholecalciferol.Fosnetupitant The metabolism of Cholecalciferol can be decreased when combined with Fosnetupitant.Fosphenytoin The serum concentration of Cholecalciferol can be decreased when it is combined with Fosphenytoin.Fusidic acid The metabolism of Fusidic acid can be decreased when combined with Cholecalciferol.Galantamine The metabolism of Galantamine can be decreased when combined with Cholecalciferol.Gefitinib The metabolism of Gefitinib can be decreased when combined with Cholecalciferol.Glofitamab The serum concentration of Cholecalciferol can be increased when it is combined with Glofitamab.Haloperidol The serum concentration of Haloperidol can be increased when it is combined with Cholecalciferol.Hydrochlorothiazide The risk or severity of hypercalcemia can be increased when Hydrochlorothiazide is combined with Cholecalciferol.Hydrocodone The metabolism of Hydrocodone can be decreased when combined with Cholecalciferol.Hydrocortisone The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Hydrocortisone.Hydrocortisone acetate The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Hydrocortisone acetate.Hydrocortisone The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Hydrocortisone butyrate.Hydrocortisone cyp The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Hydrocortisone cypionate.Hydrocortisone succ The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Hydrocortisone succinate.Hydroflumethiazide The risk or severity of hypercalcemia can be increased when Hydroflumethiazide is combined with Cholecalciferol.Hydrotalcite The serum concentration of Hydrotalcite can be increased when it is combined with Cholecalciferol.Hydroxychloroquine The metabolism of Hydroxychloroquine can be decreased when combined with Cholecalciferol.Ibrutinib The metabolism of Ibrutinib can be decreased when combined with Cholecalciferol.Idarubicin The metabolism of Idarubicin can be decreased when combined with Cholecalciferol.Iloperidone The metabolism of Iloperidone can be decreased when combined with Cholecalciferol.Imatinib The metabolism of Imatinib can be decreased when combined with Cholecalciferol.Imipramine The metabolism of Imipramine can be decreased when combined with Cholecalciferol.Indalpine The metabolism of Cholecalciferol can be decreased when combined with Indalpine.Indapamide The risk or severity of hypokalemia can be increased when Cholecalciferol is combined with Indapamide.Indenolol The metabolism of Indenolol can be decreased when combined with Cholecalciferol.Indinavir The metabolism of Cholecalciferol can be decreased when combined with Indinavir.Ipecac The metabolism of Ipecac can be decreased when combined with Cholecalciferol.Iptacopan The metabolism of Iptacopan can be decreased when combined with Cholecalciferol.Isavuconazole The metabolism of Cholecalciferol can be decreased when combined with Isavuconazole.Isavuconazonium The metabolism of Cholecalciferol can be decreased when combined with Isavuconazonium.Isoniazid The metabolism of Cholecalciferol can be decreased when combined with Isoniazid.Isradipine The metabolism of Cholecalciferol can be decreased when combined with Isradipine.Istradefylline The metabolism of Istradefylline can be decreased when combined with Cholecalciferol.Itraconazole The metabolism of Cholecalciferol can be decreased when combined with Itraconazole.Ivacaftor The serum concentration of Cholecalciferol can be increased when it is combined with Ivacaftor.Ivosidenib The metabolism of Cholecalciferol can be increased when combined with Ivosidenib.Ketoconazole The metabolism of Cholecalciferol can be decreased when combined with Ketoconazole.Labetalol The metabolism of Labetalol can be decreased when combined with Cholecalciferol.Levobetaxolol The metabolism of Levobetaxolol can be decreased when combined with Cholecalciferol.Levoketoconazole The metabolism of Cholecalciferol can be decreased when combined with Levoketoconazole.Lidocaine The metabolism of Lidocaine can be decreased when combined with Cholecalciferol.Linagliptin The metabolism of Cholecalciferol can be decreased when combined with Linagliptin.Lisdexamfetamine The serum concentration of dextroamphetamine, an active metabolite of Lisdexamfetamine, can be increased when used in combination with Cholecalciferol.Lisuride The metabolism of Lisuride can be decreased when combined with Cholecalciferol.Lofexidine The metabolism of Lofexidine can be decreased when combined with Cholecalciferol.Lonafarnib The metabolism of Cholecalciferol can be decreased when combined with Lonafarnib.Lopinavir The metabolism of Cholecalciferol can be decreased when combined with Lopinavir.Lorcaserin The metabolism of Lorcaserin can be decreased when combined with Cholecalciferol.Lorpiprazole The metabolism of Lorpiprazole can be decreased when combined with Cholecalciferol.Lumacaftor The metabolism of Cholecalciferol can be increased when combined with Lumacaftor.Magaldrate The serum concentration of Magaldrate can be increased when it is combined with Cholecalciferol.Magnesium carbonate The serum concentration of Magnesium carbonate can be increased when it is combined with Cholecalciferol.Magnesium chloride The serum concentration of Magnesium chloride can be increased when it is combined with Cholecalciferol.Magnesium hydroxide The serum concentration of Magnesium hydroxide can be increased when it is combined with Cholecalciferol.Magnesium salicylate The serum concentration of Magnesium salicylate can be increased when it is combined with Cholecalciferol.Magnesium silicate The serum concentration of Magnesium silicate can be increased when it is combined with Cholecalciferol.Magnesium trisilicate The serum concentration of Magnesium trisilicate can be increased when it is combined with Cholecalciferol.Maprotiline The metabolism of Maprotiline can be decreased when combined with Cholecalciferol.Mavacamten The serum concentration of Cholecalciferol can be decreased when it is combined with Mavacamten.Meclizine The metabolism of Meclizine can be decreased when combined with Cholecalciferol.Mephenytoin The metabolism of Mephenytoin can be decreased when combined with Cholecalciferol.Meprednisone The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Meprednisone.Mesoridazine The metabolism of Mesoridazine can be decreased when combined with Cholecalciferol.Metamfetamine The metabolism of Metamfetamine can be decreased when combined with Cholecalciferol.Methadone The metabolism of Methadone can be decreased when combined with Cholecalciferol.Methimazole The metabolism of Cholecalciferol can be decreased when combined with Methimazole.Methotrimeprazine The metabolism of Methotrimeprazine can be decreased when combined with Cholecalciferol.Methoxyflurane The metabolism of Methoxyflurane can be decreased when combined with Cholecalciferol.Methyclothiazide The risk or severity of hypercalcemia can be increased when Methyclothiazide is combined with Cholecalciferol.Methylene blue The metabolism of Methylene blue can be decreased when combined with Cholecalciferol.Methylprednisolone The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Methylprednisolone.Methylprednisolone The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Methylprednisolone aceponate.Methylprednisolone The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Methylprednisolone hemisuccinate.Metoclopramide The metabolism of Metoclopramide can be decreased when combined with Cholecalciferol.Metolazone The risk or severity of hypokalemia can be increased when Cholecalciferol is combined with Metolazone.Metoprolol The metabolism of Metoprolol can be decreased when combined with Cholecalciferol.Metreleptin The metabolism of Cholecalciferol can be increased when combined with Metreleptin.Mexiletine The metabolism of Mexiletine can be decreased when combined with Cholecalciferol.Mianserin The metabolism of Mianserin can be decreased when combined with Cholecalciferol.Miconazole The metabolism of Cholecalciferol can be decreased when combined with Miconazole.Midostaurin The metabolism of Cholecalciferol can be decreased when combined with Midostaurin.Milnacipran The metabolism of Cholecalciferol can be decreased when combined with Milnacipran.Minaprine The metabolism of Minaprine can be decreased when combined with Cholecalciferol.Mineral oil Mineral oil can cause a decrease in the absorption of Cholecalciferol resulting in a reduced serum concentration and potentially a decrease in efficacy.Mirabegron The metabolism of Mirabegron can be decreased when combined with Cholecalciferol.Mirtazapine The metabolism of Mirtazapine can be decreased when combined with Cholecalciferol.Mitotane The metabolism of Cholecalciferol can be increased when combined with Mitotane.Moclobemide The metabolism of Moclobemide can be decreased when combined with Cholecalciferol.Mometasone The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Mometasone.Mometasone furoate The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Mometasone furoate.Nadolol The metabolism of Nadolol can be decreased when combined with Cholecalciferol.Nateglinide The metabolism of Nateglinide can be decreased when combined with Cholecalciferol.Nebivolol The metabolism of Nebivolol can be decreased when combined with Cholecalciferol.Nefazodone The metabolism of Cholecalciferol can be decreased when combined with Nefazodone.Nelfinavir The metabolism of Cholecalciferol can be decreased when combined with Nelfinavir.Netupitant The metabolism of Netupitant can be decreased when combined with Cholecalciferol.Nevirapine The metabolism of Nevirapine can be decreased when combined with Cholecalciferol.Nicardipine The metabolism of Cholecalciferol can be decreased when combined with Nicardipine.Nicergoline The metabolism of Nicergoline can be decreased when combined with Cholecalciferol.Nifedipine The metabolism of Nifedipine can be decreased when combined with Cholecalciferol.Nilotinib The metabolism of Cholecalciferol can be decreased when combined with Nilotinib.Nilvadipine The metabolism of Cholecalciferol can be decreased when combined with Nilvadipine.Nirogacestat The metabolism of Nirogacestat can be decreased when combined with Cholecalciferol.Nortriptyline The metabolism of Nortriptyline can be decreased when combined with Cholecalciferol.Olanzapine The metabolism of Olanzapine can be decreased when combined with Cholecalciferol.Oliceridine The serum concentration of Oliceridine can be increased when it is combined with Cholecalciferol.Omaveloxolone The serum concentration of Cholecalciferol can be decreased when it is combined with Omaveloxolone.Ondansetron The metabolism of Ondansetron can be decreased when combined with Cholecalciferol.Opium The metabolism of Opium can be decreased when combined with Cholecalciferol.Orlistat Orlistat can cause a decrease in the absorption of Cholecalciferol resulting in a reduced serum concentration and potentially a decrease in efficacy.Ouabain The risk or severity of ventricular arrhythmias and Cardiac Arrhythmia can be increased when Cholecalciferol is combined with Ouabain.Oxprenolol The metabolism of Oxprenolol can be decreased when combined with Cholecalciferol.Oxycodone The metabolism of Oxycodone can be decreased when combined with Cholecalciferol.Oxymorphone The metabolism of Oxymorphone can be decreased when combined with Cholecalciferol.Paliperidone The metabolism of Paliperidone can be decreased when combined with Cholecalciferol.Palonosetron The metabolism of Palonosetron can be decreased when combined with Cholecalciferol.Paricalcitol The risk or severity of adverse effects can be increased when Cholecalciferol is combined with Paricalcitol.Paroxetine The metabolism of Paroxetine can be decreased when combined with Cholecalciferol.Pazopanib The metabolism of Pazopanib can be decreased when combined with Cholecalciferol.Penbutolol The metabolism of Penbutolol can be decreased when combined with Cholecalciferol.Pentamidine The metabolism of Pentamidine can be decreased when combined with Cholecalciferol.Pentobarbital The metabolism of Cholecalciferol can be increased when combined with Pentobarbital.Perhexiline The metabolism of Perhexiline can be decreased when combined with Cholecalciferol.Perphenazine The metabolism of Perphenazine can be decreased when combined with Cholecalciferol.Phenacetin The metabolism of Phenacetin can be decreased when combined with Cholecalciferol.Phenformin The metabolism of Phenformin can be decreased when combined with Cholecalciferol.Phenobarbital The metabolism of Cholecalciferol can be increased when combined with Phenobarbital.Phenytoin The metabolism of Phenytoin can be decreased when combined with Cholecalciferol.Pimozide The metabolism of Pimozide can be decreased when combined with Cholecalciferol.Pindolol The metabolism of Pindolol can be decreased when combined with Cholecalciferol.Piperazine The metabolism of Piperazine can be decreased when combined with Cholecalciferol.Pipotiazine The metabolism of Pipotiazine can be decreased when combined with Cholecalciferol.Pirfenidone The metabolism of Pirfenidone can be decreased when combined with Cholecalciferol.Pitolisant The serum concentration of Cholecalciferol can be decreased when it is combined with Pitolisant.Polythiazide The risk or severity of hypercalcemia can be increased when Polythiazide is combined with Cholecalciferol.Ponatinib The metabolism of Ponatinib can be decreased when combined with Cholecalciferol.Posaconazole The metabolism of Cholecalciferol can be decreased when combined with Posaconazole.Practolol The metabolism of Practolol can be decreased when combined with Cholecalciferol.Prednisolone The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Prednisolone.Prednisolone acetate The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Prednisolone acetate.Prednisolone phosp The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Prednisolone phosphate.Prednisone The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Prednisone.Prednisone acetate The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Prednisone acetate.Primaquine The metabolism of Cholecalciferol can be decreased when combined with Primaquine.Primidone The metabolism of Cholecalciferol can be increased when combined with Primidone.Procainamide The metabolism of Procainamide can be decreased when combined with Cholecalciferol.Prochlorperazine The metabolism of Prochlorperazine can be decreased when combined with Cholecalciferol.Progesterone The metabolism of Progesterone can be decreased when combined with Cholecalciferol.Promazine The metabolism of Promazine can be decreased when combined with Cholecalciferol.Promethazine The metabolism of Promethazine can be decreased when combined with Cholecalciferol.Propafenone The metabolism of Propafenone can be decreased when combined with Cholecalciferol.Propranolol The metabolism of Propranolol can be decreased when combined with Cholecalciferol.Quetiapine The metabolism of Quetiapine can be decreased when combined with Cholecalciferol.Quinethazone The risk or severity of hypokalemia can be increased when Cholecalciferol is combined with Quinethazone.Quinine The metabolism of Quinine can be decreased when combined with Cholecalciferol.Ranolazine The metabolism of Ranolazine can be decreased when combined with Cholecalciferol.Remoxipride The metabolism of Remoxipride can be decreased when combined with Cholecalciferol.Revefenacin The metabolism of Revefenacin can be decreased when combined with Cholecalciferol.Ribociclib The metabolism of Cholecalciferol can be decreased when combined with Ribociclib.Rifampin The metabolism of Cholecalciferol can be increased when combined with Rifampicin.Rifapentine The metabolism of Cholecalciferol can be increased when combined with Rifapentine.Risperidone The metabolism of Risperidone can be decreased when combined with Cholecalciferol.Ritlecitinib The serum concentration of Cholecalciferol can be increased when it is combined with Ritlecitinib.Ritonavir The serum concentration of Cholecalciferol can be increased when it is combined with Ritonavir.Rotigotine The metabolism of Rotigotine can be decreased when combined with Cholecalciferol.Rucaparib The metabolism of Rucaparib can be decreased when combined with Cholecalciferol.Rupatadine The metabolism of Rupatadine can be decreased when combined with Cholecalciferol.Saquinavir The metabolism of Cholecalciferol can be decreased when combined with Saquinavir.Satralizumab The serum concentration of Cholecalciferol can be decreased when it is combined with Satralizumab.Selegiline The metabolism of Selegiline can be decreased when combined with Cholecalciferol.Sertindole The metabolism of Sertindole can be decreased when combined with Cholecalciferol.Sertraline The metabolism of Sertraline can be decreased when combined with Cholecalciferol.Sevelamer The serum concentration of Cholecalciferol can be decreased when it is combined with Sevelamer.Sildenafil The metabolism of Sildenafil can be decreased when combined with Cholecalciferol.Simeprevir The metabolism of Cholecalciferol can be decreased when combined with Simeprevir.Simvastatin The metabolism of Simvastatin can be decreased when combined with Cholecalciferol.Solifenacin The metabolism of Solifenacin can be decreased when combined with Cholecalciferol.Somatrogon The metabolism of Cholecalciferol can be increased when combined with Somatrogon.Sotalol The metabolism of Sotalol can be decreased when combined with Cholecalciferol.Sotorasib The serum concentration of Cholecalciferol can be decreased when it is combined with Sotorasib.Sparteine The metabolism of Sparteine can be decreased when combined with Cholecalciferol.St. John's Wort The metabolism of Cholecalciferol can be increased when combined with St. John's Wort.Stiripentol The metabolism of Cholecalciferol can be decreased when combined with Stiripentol.Sucralfate The serum concentration of Sucralfate can be increased when it is combined with Cholecalciferol.Tafenoquine The metabolism of Tafenoquine can be decreased when combined with Cholecalciferol.Talc The serum concentration of Talc can be increased when it is combined with Cholecalciferol.Tamoxifen The metabolism of Tamoxifen can be decreased when combined with Cholecalciferol.Tamsulosin The metabolism of Tamsulosin can be decreased when combined with Cholecalciferol.Tegaserod The metabolism of Tegaserod can be decreased when combined with Cholecalciferol.Telaprevir The metabolism of Cholecalciferol can be decreased when combined with Telaprevir.Telithromycin The metabolism of Cholecalciferol can be decreased when combined with Telithromycin.Telotristat ethyl The serum concentration of Cholecalciferol can be decreased when it is combined with Telotristat ethyl.Terfenadine The metabolism of Cholecalciferol can be decreased when combined with Terfenadine.Tetrabenazine The metabolism of Tetrabenazine can be decreased when combined with Cholecalciferol.Theophylline The metabolism of Theophylline can be decreased when combined with Cholecalciferol.Thioridazine The metabolism of Thioridazine can be decreased when combined with Cholecalciferol.Ticlopidine The metabolism of Ticlopidine can be decreased when combined with Cholecalciferol.Timolol The metabolism of Timolol can be decreased when combined with Cholecalciferol.Tiotropium The metabolism of Tiotropium can be decreased when combined with Cholecalciferol.Tipranavir The metabolism of Cholecalciferol can be decreased when combined with Tipranavir.Tixocortol The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Tixocortol.Tolterodine The metabolism of Tolterodine can be decreased when combined with Cholecalciferol.Trabectedin The metabolism of Trabectedin can be decreased when combined with Cholecalciferol.Tramadol The metabolism of Tramadol can be decreased when combined with Cholecalciferol.Trazodone The metabolism of Trazodone can be decreased when combined with Cholecalciferol.Triamcinolone The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Triamcinolone.Trichlormethiazide The risk or severity of hypercalcemia can be increased when Trichlormethiazide is combined with Cholecalciferol.Triclabendazole The metabolism of Triclabendazole can be decreased when combined with Cholecalciferol.Trilostane The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Trilostane.Trimipramine The metabolism of Trimipramine can be decreased when combined with Cholecalciferol.Troleandomycin The metabolism of Cholecalciferol can be decreased when combined with Troleandomycin.Tucatinib The metabolism of Tucatinib can be decreased when combined with Cholecalciferol.Umeclidinium The metabolism of Umeclidinium can be decreased when combined with Cholecalciferol.Vadadustat The serum concentration of Cholecalciferol can be increased when it is combined with Vadadustat.Valbenazine The metabolism of Valbenazine can be decreased when combined with Cholecalciferol.Vamorolone The therapeutic efficacy of Cholecalciferol can be decreased when used in combination with Vamorolone.Venetoclax The metabolism of Cholecalciferol can be decreased when combined with Venetoclax.Venlafaxine The metabolism of Venlafaxine can be decreased when combined with Cholecalciferol.Verapamil The metabolism of Cholecalciferol can be decreased when combined with Verapamil.Vernakalant The metabolism of Vernakalant can be decreased when combined with Cholecalciferol.Vilazodone The metabolism of Vilazodone can be decreased when combined with Cholecalciferol.Viloxazine The metabolism of Cholecalciferol can be decreased when combined with Viloxazine.Voriconazole The metabolism of Cholecalciferol can be decreased when combined with Voriconazole.Vortioxetine The metabolism of Vortioxetine can be decreased when combined with Cholecalciferol.Xanomeline The metabolism of Xanomeline can be decreased when combined with Cholecalciferol.Yohimbine The metabolism of Yohimbine can be decreased when combined with Cholecalciferol.Zimelidine The metabolism of Cholecalciferol can be decreased when combined with Zimelidine.Ziprasidone The metabolism of Cholecalciferol can be decreased when combined with Ziprasidone.Zolpidem The metabolism of Zolpidem can be decreased when combined with Cholecalciferol.Zuclopenthixol The metabolism of Zuclopenthixol can be decreased when combined with Cholecalciferol.Pregnancy and Lactation FDA Pregnancy Category : C Pregnancy No data are available for cholecalciferol (vitamin D3). Administration of high doses (≥10,000 IU/every other day) of ergocalciferol (vitamin D2) to pregnant rabbits resulted in abortions and an increased incidence of fetal aortic stenosis. Administration of vitamin D2 (40,000 IU/day) to pregnant rats resulted in neonatal death, decreased fetal weight, and impaired osteogenesis of long bones postnatally. There are no studies in pregnant women. FOSAMAX PLUS D should be used during pregnancy only if the potential benefit justifies the potential risk to the mother and fetus. Nursing Mothers Cholecalciferol and some of its active metabolites pass into breast milk. It is not known whether alendronate is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when FOSAMAX PLUS D is administered to nursing women. Warning Health Risks from Excessive Vitamin DExcess amounts of vitamin D are toxic. Because vitamin D increases calcium absorption in the gastrointestinal tract, vitamin D toxicity results in marked hypercalcemia (total calcium greater than 11.1 mg/dL, beyond the normal range of 8.4 to 10.2 mg/dL), hypercalciuria, and high serum 25(OH)D levels (typically greater than 375 nmol/l [150 ng/mL]) [1rx]. Hypercalcemia, in turn, can lead to nausea, vomiting, muscle weakness, neuropsychiatric disturbances, pain, loss of appetite, dehydration, polyuria, excessive thirst, and kidney stones.In extreme cases, vitamin D toxicity causes renal failure, calcification of soft tissues throughout the body (including in coronary vessels and heart valves), cardiac arrhythmias, and even death. Vitamin D toxicity has been caused by consumption of dietary supplements that contained excessive vitamin D amounts because of manufacturing errors, that were taken inappropriately or in excessive amounts, or that were incorrectly prescribed by physicians, [rx-rx].Experts do not believe that excessive sun exposure results in vitamin D toxicity because thermal activation of previtamin D3 in the skin gives rise to various non-vitamin D forms that limit formation of vitamin D3. Some vitamin D3 is also converted to nonactive forms [rx]. However, frequent use of tanning beds, which provide artificial UV radiation, can lead to 25(OH)D levels well above 375–500 nmol/L (150–200 ng/mL) [rx-rx].The combination of high intakes of calcium (about 2,100 mg/day from food and supplements) with moderate amounts of vitamin D (about 19 mcg [765 IU]/day from food and supplements) increased the risk of kidney stones by 17% over 7 years among 36,282 postmenopausal women who were randomly assigned to take 1,000 mg/day calcium and 10 mcg (400 IU)/day vitamin D or a placebo [rx]. However, other, shorter (from 24 weeks to 5 years) clinical trials of vitamin D supplementation alone or with calcium in adults found greater risks of hypercalcemia and hypercalciuria, but not of kidney stones [rx,rx].The FNB established ULs for vitamin D in 2010 (Table 4) [1]. While acknowledging that signs and symptoms of toxicity are unlikely at daily intakes below 250 mcg (10,000 IU), the FNB noted that even vitamin D intakes lower than the ULs might have adverse health effects over time. The FNB recommended avoiding serum 25(OH)D levels above approximately 125–150 nmol/L (50–60 ng/mL), and it found that even lower serum levels (approximately 75–120 nmol/L [30–48 ng/mL]) are associated with increases in rates of all-cause mortality, risk of cancer at some sites (e.g., pancreas), risk of cardiovascular events, and number of falls and fractures among older adults. Table 4: Tolerable Upper Intake Levels (ULs) for Vitamin D [1]Age Male Female Pregnancy Lactation0–6 months 25 mcg (1,000 IU) 25 mcg (1,000 IU)7–12 months 38 mcg (1,500 IU) 38 mcg (1,500 IU)1–3 years 63 mcg (2,500 IU) 63 mcg (2,500 IU)4–8 years 75 mcg (3,000 IU) 75 mcg (3,000 IU)9–18 years 100 mcg (4,000 IU) 100 mcg (4,000 IU) 100 mcg (4,000 IU) 100 mcg (4,000 IU)19+ years 100 mcg (4,000 IU) 100 mcg (4,000 IU) 100 mcg (4,000 IU) 100 mcg (4,000 IU)How should this medicine be used?

Cholecalciferol (vitamin D3) comes as a capsule, gel capsule, chewable gel (gummy), tablet, and liquid drops to take by mouth. It is usually taken once or twice daily depending on the preparation, your age, and your medical condition(s). Cholecalciferol is available without a prescription, but your doctor may prescribe cholecalciferol to treat certain conditions. Check with your doctor or pharmacist before taking a cholecalciferol (vitamin D) supplement. Take cholecalciferol at around the same time every day. Follow the directions on…

Before taking cholecalciferol,tell your doctor and pharmacist if you are allergic to cholecalciferol, any other medications, or any of the ingredients in cholecalciferol products. Ask your pharmacist for a list of the ingredients. tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take while taking cholecalciferol. Your doctor may need to change the doses of your medications or monitor you carefully for side effects. tell your doctor if you have or have ever had hyperparathyroidism (a condition in which the body produces too much parathyroid hormone [PTH; a natural substance needed to control the amount of calcium in the blood]), kidney disease, or have high blood levels of calcium. tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking cholecalciferol (vitamin D3), call your doctor.What special dietary instructions should I follow?

When cholecalciferol (vitamin D3) is used to treat and prevent bone diseases, you should eat and drink of foods and drinks that are rich in calcium. If you find it difficult to eat enough calcium-rich foods, tell your doctor. In that case, your doctor can prescribe or recommend a calcium supplement. Unless your doctor tells you otherwise, continue your normal diet.

What should I do if I forget a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one. https://www.accessdata.fda.gov/drugsatfda_docs/label/2011/021762s013lbl.pdf https://www.accessdata.fda.gov/drugsatfda_docs/label/2010/021762s005s009s010lbl.pdf https://www.drugs.com/sfx/vitamin-d3-side-effects.html https://pubchem.ncbi.nlm.nih.gov/compound/Vitamin-D3-d3#section=Information-Sources https://medlineplus.gov/druginfo/meds/a620058.html https://go.drugbank.com/drugs/DB00169 https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/ https://pubchem.ncbi.nlm.nih.gov/compound/Cholecalciferol https://www.amazon.com/Nature-Made-Vitamin-1000-Softgels/dp/B004U3Y8OM (http://creativecommons.org/licenses/by-nc/4.0/legalcode) https://www.drugbank.ca/legal/terms_of_use https://www.drugbank.ca/drugs/DB00169 https://www.cancer.gov/policies/copyright-reuse https://ncithesaurus.nci.nih.gov/ncitbrowser/ConceptReport.jsp?dictionary=NCI_Thesaurus&ns=ncit&code=C48194 https://echa.europa.eu/web/guest/legal-notice https://echa.europa.eu/substance-information/-/substanceinfo/100.224.118 https://echa.europa.eu/information-on-chemicals/cl-inventory-database/-/discli/details/230162 https://www.nlm.nih.gov/web_policies.html https://pubchem.ncbi.nlm.nih.gov/source/hsdb/820 https://www.epa.govt.nz/about-this-site/general-copyright-statement/ https://www.epa.govt.nz/industry-areas/hazardous-substances/guidance-for-importers-and-manufacturers/hazardous-substances-databases/ http://creativecommons.org/licenses/by-nc-nd/4.0/ ) https://www.ncbi.nlm.nih.gov/books/n/statpearls/article-19447/ https://www.fda.gov/about-fda/about-website/website-policies#linking https://www.accessdata.fda.gov/scripts/cder/daf/ https://www.clinicaltrialsregister.eu/ https://ec.europa.eu/food/plant/pesticides/eu-pesticides-database/start/screen/active-substances/details/554 https://www.fda.gov/about-fda/about-website/website-policies#linking https://www.fda.gov/drugs/drug-approvals-and-databases/approved-drug-products-therapeutic-equivalence-evaluations-orange-book https://haz-map.com/About https://haz-map.com/Agents/12963 https://www.kegg.jp/kegg/legal.html https://www.kegg.jp/entry/C05443 https://www.kegg.jp/entry/D00188 National Drug…

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