Calcidol

Cholecalciferol Supplements
Ergocalciferol Supplements

While vitamin D may be taken without regard to food, it is better absorbed when taken with foods containing fat.

Some formulations of vitamin D oral solution/drops contain propylene glycol. When selecting oral liquid preparations for neonates, infants, and young children, ensure the correct formulation of vitamin D is chosen to avoid propylene glycol toxicity.
Administer using a calibrated measuring device to ensure dosage accuracy. Due to the risk of inadvertently administering an incorrect dose to infants, the FDA recommends using a product with a dropper that will measure no more than 10 mcg (400 International Units) per dose.
Administer directly into the mouth or mix with breast milk, formula, fruit juice, cereal, or other foods. If mixed, make sure the patient drinks or eats the entire portion to ensure they receive the total amount of the medication.
Storage: After opening, store away from direct light.

hypervitaminosis D / Delayed / 0-1.0

hypercalcemia / Delayed / 0-1.0
constipation / Delayed / 0-1.0
hypercalciuria / Delayed / 0-1.0

vomiting / Early / 0-1.0
headache / Early / 0-1.0
polyuria / Early / 0-1.0
irritability / Delayed / 0-1.0
fatigue / Early / 0-1.0
nausea / Early / 0-1.0
increased urinary frequency / Early / 0-1.0
anorexia / Delayed / 0-1.0
polydipsia / Early / 0-1.0
weight loss / Delayed / 0-1.0

Calcidol, Calciferol, D-Vita, D3 Vitamin, DECARA, Deltalin, Dialyvite, Dialyvite Vitamin D, Dialyvite Vitamin D3, Drisdol, Enfamil D-Vi-Sol, Ergo D, Fiber with Vitamin D3 Gummies Gluten-Free, Happy Sunshine Vitamin D3, MAXIMUM D3, PureMark Naturals Vitamin D, Replesta, Replesta Children's, Super Happy SUNSHINE Vitamin D3, Thera-D 2000, Thera-D 4000, Thera-D Rapid Repletion, THERA-D SPORT, UpSpring Baby Vitamin D3, YumVs, YumVs Kids ZERO, YumVs ZERO

Rx, OTC

Vitamin involved in calcium and phosphate balance and normal bone growth and mineralization
Found in fortified milk and cereal products, fish, liver, and egg yolks
Used for prevention and treatment of vitamin D deficiency and rickets

20 mcg/day (800 International Units/day) PO is the RDA.

15 mcg/day (600 International Units/day) PO is the RDA.

15 mcg/day (600 International Units/day) PO is the RDA. 10 mcg/day (400 International Units/day) PO is recommended if the adolescent is not obtaining at least 10 mcg (400 International Units) through dietary sources. All dietary sources of vitamin D (e.g., fortified milk, eggs, other food) may be included in determining the daily intake.

15 mcg/day (600 International Units/day) PO is the RDA. 10 mcg/day (400 International Units/day) PO is recommended if the child is consuming less than 1 L/day of vitamin D-fortified milk.

10 mcg/day (400 International Units/day) PO is the recommended Adequate Intake based on dietary intake of breast milk, formula, or other food sources. No RDA has been established. Infants that are exclusively breast-fed without vitamin D supplements are at increased risk for deficiency. Because most exclusively formula-fed infants ingest nearly 1 L/day of formula after the first month of life, they will achieve a vitamin D intake of 10 mcg/day (400 International Units/day). Infants who receive a mixture of human milk and formula should get a vitamin D supplement of 10 mcg/day (400 International Units/day) to ensure the AI value. As infants are weaned from human milk and/or formula, intake of vitamin D-fortified milk should be encouraged to provide at least 10 mcg/day (400 International Units/day) of vitamin D. Vitamin D supplementation should continue until the infant consumes at least 1 L/day (1 quart/day) of vitamin D-fortified milk (Whole milk (cow's milk) is not recommended until after 12 months of age).

10 mcg/day (400 International Units/day) PO is the recommended Adequate Intake based on dietary intake of breast milk, formula, or other food sources. No RDA has been established. Infants that are exclusively breast-fed without vitamin D supplements are at increased risk for deficiency. Because most exclusively formula-fed infants ingest nearly 1 L/day of formula after the first month of life, they will achieve a vitamin D intake of 10 mcg/day (400 International Units/day). Infants who receive a mixture of human milk and formula should get a vitamin D supplement of 10 mcg/day (400 International Units/day) to ensure the AI value. As infants are weaned from human milk and/or formula, intake of vitamin D-fortified milk should be encouraged to provide at least 10 mcg/day (400 International Units/day) of vitamin D. Vitamin D supplementation should continue until the infant consumes at least 1 L/day (1 quart/day) of vitamin D-fortified milk (Whole milk (cow's milk) is not recommended until after 12 months of age).

10 mcg/day (400 International Units/day) PO.

5 to 10 mcg/day (200 to 400 International Units/day) PO. If the infant is receiving less than 10 mcg/day (400 International Units/day), increase the dosage to 10 mcg/day (400 International Units/day) when a weight of more than 1.5 kg is reached and full enteral nutrition is tolerated.

20 to 50 mcg (800 to 2,000 International Units) PO once daily. Adjust dosage to maintain serum 25-hydroxyvitamin D concentrations of 30 ng/mL or more. Max: 250 mcg/day (10,000 International Units/day).

20 to 50 mcg (800 to 2,000 International Units) PO once daily. Adjust dosage to maintain serum 25-hydroxyvitamin D concentrations of 30 ng/mL or more. Max: 250 mcg/day (10,000 International Units/day).

20 to 25 mcg (800 to 1,000 International Units) PO once daily. Adjust dosage to maintain serum 25-hydroxyvitamin D concentrations of 30 ng/mL or more. Max: 100 mcg/day (4,000 International Units/day).

10 to 12.5 mcg (400 to 500 International Units) PO once daily. Adjust dosage to maintain serum 25-hydroxyvitamin D concentrations of 30 ng/mL or more. Max: 50 mcg/day (2,000 International Units/day).

10 to 12.5 mcg (400 to 500 International Units) PO once daily. Adjust dosage to maintain serum 25-hydroxyvitamin D concentrations of 30 ng/mL or more. Max: 50 mcg/day (2,000 International Units/day).

50 mcg (2,000 International Units) PO once daily.

50 mcg (2,000 International Units) PO once daily.

75 mcg (3,000 International Units) PO once daily until serum vitamin D concentration is more than 30 ng/mL.

7,000 to 10,000 mcg (280,000 to 400,000 International Units) PO loading dose divided in daily or weekly doses over 6 to 10 weeks to achieve a serum vitamin D concentration more than 30 ng/mL, then 20 to 100 mcg (800 to 4,000 International Units) PO once daily or given intermittently at higher equivalent dose starting 1 month after loading. Example loading dose regimens include: 100 mcg (4,000 International Units) PO once daily for 10 weeks; 150 mcg (6,000 International Units) PO once daily for 8 weeks; 1,000 mcg (40,000 International Units) once weekly for 7 weeks; or 1,250 mcg (50,000 International Units) PO once weekly for 6 to 8 weeks. Individualize dose based on serum vitamin D concentrations.[62269] [62274]

50 to 125 mcg (2,000 to 5,000 International Units) PO once daily or 350 to 1,250 mcg (14,000 to 50,000 International Units) PO once weekly for at least 6 weeks to achieve a serum vitamin D concentration more than 30 ng/mL, then 15 to 25 mcg (600 to 1,000 International Units) PO once daily.   Maintenance doses of 1,250 mcg (50,000 International Units) PO once monthly have also been used. Individualize dose based on serum vitamin D concentrations.

25 to 125 mcg (1,000 to 5,000 International Units) PO once daily or 1,250 mcg (50,000 International Units) PO once weekly for at least 6 weeks to achieve a serum vitamin D concentration more than 30 ng/mL, then 10 to 25 mcg (400 to 1,000 International Units) PO once daily. Individualize dose based on serum vitamin D concentrations.  

25 to 50 mcg (1,000 to 2,000 International Units) PO once daily or 1,250 mcg (50,000 International Units) PO once weekly for at least 6 weeks to achieve a serum vitamin D concentration more than 30 ng/mL, then 10 to 25 mcg (400 to 1,000 International Units) PO once daily. Individualize dose based on serum vitamin D concentrations.  

75 to 250 mcg (3,000 to 10,000 International Units) PO once daily or 1,250 mcg (50,000 International Units) PO 1 to 3 times weekly to achieve a serum vitamin D concentration more than 30 ng/mL, then 75 to 150 mcg (3,000 to 6,000 International Units) PO once daily.

150 to 250 mcg (6,000 to 10,000 International Units) PO once daily (2 to 3 times the usual recommended dose) to achieve a serum vitamin D concentration more than 30 ng/mL, then 30 to 75 mcg (1,200 to 3,000 International Units) PO once daily.

150 to 250 mcg (6,000 to 10,000 International Units) PO once daily (2 to 3 times the usual recommended dose) to achieve a serum vitamin D concentration more than 30 ng/mL, then 20 to 75 mcg (800 to 3,000 International Units) PO once daily.

100 to 150 mcg (4,000 to 6,000 International Units) PO once daily (2 to 3 times the usual recommended dose) to achieve a serum vitamin D concentration more than 30 ng/mL, then 20 to 75 mcg (800 to 3,000 International Units) PO once daily.

40 to 150 mcg (1,600 to 6,000 International Units) PO once daily, initially. May increase the dose to a maximum of 250 mcg (10,000 International Units) PO once daily to maintain a serum vitamin D concentration of at least 30 ng/mL (75 mmol/L).

40 to 150 mcg (1,600 to 6,000 International Units) PO once daily, initially. May increase the dose to a maximum of 250 mcg (10,000 International Units) PO once daily to maintain a serum vitamin D concentration of at least 30 ng/mL (75 mmol/L).

40 to 75 mcg (1,600 to 3,000 International Units) PO once daily, initially. May increase the dose to a maximum of 100 mcg (4,000 International Units) PO once daily to maintain a serum vitamin D concentration of at least 30 ng/mL (75 mmol/L).

20 to 25 mcg (800 to 1,000 International Units) PO once daily, initially. May increase the dose to a maximum of 50 mcg (2,000 International Units) PO once daily to maintain a serum vitamin D concentration of at least 30 ng/mL (75 mmol/L).

20 to 25 mcg (800 to 1,000 International Units) PO once daily, initially. May increase the dose to a maximum of 50 mcg (2,000 International Units) PO once daily to maintain a serum vitamin D concentration of at least 30 ng/mL (75 mmol/L).

50 to 500 mcg (2,000 to 20,000 International Units) PO daily for 4 to 8 weeks, with the duration of treatment determined by evidence of radiologic healing. Thereafter, supplement with the RDA to prevent further deficiency. Alternatively, at least 125 mcg (5,000 International Units) PO once daily has also been recommended for initial treatment; weekly regimens (e.g., high doses, such as 1,250 mcg [50,000 International Units] PO once weekly) or a single higher-dose course over 1 to 5 days may be considered if compliance is an issue that prevents adequate repletion. Large single dose regimens (5,000 to 15,000 mcg [200,000 to 600,000 International Units] PO divided into 2 to 4 doses administered over 1 day) have been used when compliance is a concern, but are sometimes controversial due to a purported risk for hypercalcemia. It is important to ensure adequate dietary intake of calcium and phosphorus. Active treatment may continue for 2 to 3 months to replete deficient stores, followed by maintenance dosing with the RDA. Individualize dose based upon 25(OH)D concentrations.

25 to 125 mcg (1,000 to 5,000 International Units) PO once daily has been recommended. Radiologic evidence of healing is usually observed in 2 to 4 weeks, and the active treatment duration is usually 2 to 3 months, after which the supplementation may be reduced to maintenance dosing in accordance with RDAs to prevent further deficiency. Supplementation with calcium is necessary due to the risk of hypocalcemia during bone remineralization. It is important to ensure adequate dietary intake of calcium and phosphorus. Weekly regimens (e.g., high doses, such as 1,250 mcg [50,000 International Units] PO once weekly) have been considered in older infants if compliance is an issue that prevents adequate repletion. Individualize dose based upon 25(OH)D concentrations.

25 mcg (1,000 International Units) PO once daily has been recommended. Radiologic evidence of healing is usually observed in 2 to 4 weeks, and the active treatment duration is usually 2 to 3 months, after which the supplementation may be reduced to maintenance dosing in accordance with RDAs to prevent further deficiency. Supplementation with calcium is necessary due to the risk of hypocalcemia during bone remineralization. It is important to ensure adequate dietary intake of calcium and phosphorus. Individualize dose based upon 25(OH)D concentrations.

Treatment for HVDRR is not standardized. Despite significant improvements in vitamin D concentrations following high-dose ergocalciferol (or use of a vitamin D analog like calcitriol) alone, patients may remain hypocalcemic and hypophosphatemic. High doses of ergocalciferol (vitamin D2) have been used in these patients. The following regimens have been used with variable results: 100 to 1,000 mcg/day (4,000 to 40,000 International Units/day) PO or 5 to 7 mcg/kg/day (200 to 280 International Units/kg/day) PO. However, doses as high as 5,000 mcg/day (200,000 International Units/day) PO have not been effective in improving the disease in other patients. Patients should receive a 3 to 6 month trial of high dose vitamin D along with high-dose calcium therapy. Patients without alopecia appear more likely to respond. The FDA-approved dose is 300 to 12,500 mcg (12,000 to 500,000 International Units) PO daily. Calcium intake should be adequate. Blood calcium and phosphorus determinations are recommended every 2 weeks or more frequently if clinically indicated. X-rays of the bones are recommended every month until condition is corrected and stabilized. Individualize dose based upon 25(OH)D concentrations.

20 mcg (800 International Units) PO daily; different doses may be recommended dependent on concomitant pharmacological treatment or prevention. The American College of Rheumatology recommends supplementation of vitamin D and calcium in all patients receiving corticosteroid therapy, especially if treatment duration will exceed 3 months.

20 mcg (800 International Units) PO daily. The American College of Rheumatology recommends supplementation of vitamin D and calcium in all patients receiving corticosteroid therapy, especially if treatment duration will exceed 3 months.

20 to 25 mcg (800 to 1,000 international units) PO daily is recommended by the National Osteoporosis Foundation. Supplementation regimen should include calcium for greatest benefit.

1,250 to 5,000 mcg (50,000 to 200,000 International Units) PO once daily along with calcium supplements.

1,250 to 5,000 mcg (50,000 to 200,000 International Units) PO once daily along with calcium supplements.

20 to 30 mcg (800 to 1,200 International Units) PO once daily has been recommended. Alternative regimen is 15,000 mcg (600,000 International Units) PO once every 2 months. If vitamin D supplementation is started early, it prevents development of osteopenia in these patients.

20 to 30 mcg (800 to 1,200 International Units) PO once daily has been recommended. Alternative regimen is 2,500 mcg (100,000 International Units) PO once every 2 months. If vitamin D supplementation is started early, it prevents development of osteopenia in these patients.

A total dose of 17.5 mcg (700 International Units) PO daily from a combination of dietary and non-dietary sources. In a population-based study of 3,025 females, the daily vitamin D and calcium intake was followed to determine if vitamin D or calcium had an impact on the risk of developing PMS. Women with the highest intake of vitamin D from both dietary sources and supplements (median 17.7 mcg [706 International Units daily]) had a reduced risk of developing PMS compared with those women with the lowest intake of vitamin D of 2.8 mcg (112 International Units) daily (RR of 0.59, 95% CI 0.4 to 0.86, p = 0.01 for the trend).[31641]

1,250 mcg (50,000 International Units) PO once weekly or monthly until target serum total hydroxyvitamin D concentrations are achieved.    Cholecalciferol is more effective at raising serum total 25-hydroxyvitamin D concentrations in non-dialysis-dependent CKD patients (CKD G3a-5) compared with ergocalciferol and may be preferable in these patients.  

†Indicates off-label use

Specific guidelines for dosage adjustments in hepatic impairment are not available; higher doses may be needed to compensate for reductions in intestinal absorption.

Specific guidelines for dosage adjustments in renal impairment are not available. However, vitamin D is activated in the kidney; close monitoring is required to ensure the appropriate dose.

Aluminum Hydroxide; Magnesium Hydroxide: (Major) Avoid vitamin D coadministration with magnesium hydroxide in persons on chronic hemodialysis due to the risk for hypermagnesemia.
Aluminum Hydroxide; Magnesium Hydroxide; Simethicone: (Major) Avoid vitamin D coadministration with magnesium hydroxide in persons on chronic hemodialysis due to the risk for hypermagnesemia.
Castor Oil: (Moderate) Absorption of fat-soluble vitamins may be decreased with coadministration of castor oil.
Cholestyramine: (Moderate) Cholestyramine can decrease the intestinal absorption of fat and fat-soluble vitamins. If used concurrently, administration of the two agents should be staggered for the longest time interval possible.
Colesevelam: (Moderate) It is not known if colesevelam can reduce the absorption of oral vitamin supplements including fat soluble vitamins A, D, E, and K. To minimize potential interactions, administer vitamins at least 4 hours before colesevelam.
Colestipol: (Moderate) Separate administration of fat-soluble vitamins by 1 hour before or 4 hours after a colestipol dose to limit effects on oral absorption. Because it sequesters bile acids, colestipol may interfere with normal fat absorption and thus may reduce absorption of fat-soluble vitamins.
Hydantoins: (Moderate) Phenytoin and fosphenytoin can decrease the activity of vitamin D (e.g., cholecalciferol) by increasing its metabolism. In rare cases, this has caused anticonvulsant-induced rickets and osteomalacia. Vitamin D supplementation or dosage adjustments may be required in patients who are receiving chronic treatment with anticonvulsants. (Moderate) Phenytoin and fosphenytoin can decrease the activity of vitamin D (e.g., cholecalciferol, ergocalciferol) by increasing its metabolism. In rare cases, this has caused anticonvulsant-induced rickets and osteomalacia. Vitamin D supplementation or dosage adjustments may be required in patients who are receiving chronic treatment with anticonvulsants.
Isoniazid, INH; Pyrazinamide, PZA; Rifampin: (Moderate) Rifampin is a potent inducer of the cytochrome P450 hepatic enzyme system and can decrease the plasma concentrations and possibly the efficacy of cholecalciferol, Vitamin D3. In some cases, reduced concentrations of circulating vitamin D and 1,25-dihydoxy vitamin D have been accompanied by decreased serum calcium and phosphate, and elevated parathyroid hormone. Dosage adjustments of cholecalciferol, Vitamin D3 may be required. (Moderate) Rifampin is a potent inducer of the cytochrome P450 hepatic enzyme system and can decrease the plasma concentrations and possibly the efficacy of ergocalciferol, Vitamin D2. In some cases, reduced concentrations of circulating vitamin D and 1,25-dihydoxy vitamin D have been accompanied by decreased serum calcium and phosphate, and elevated parathyroid hormone. Dosage adjustments of ergocalciferol, Vitamin D2 may be required.
Isoniazid, INH; Rifampin: (Moderate) Rifampin is a potent inducer of the cytochrome P450 hepatic enzyme system and can decrease the plasma concentrations and possibly the efficacy of cholecalciferol, Vitamin D3. In some cases, reduced concentrations of circulating vitamin D and 1,25-dihydoxy vitamin D have been accompanied by decreased serum calcium and phosphate, and elevated parathyroid hormone. Dosage adjustments of cholecalciferol, Vitamin D3 may be required. (Moderate) Rifampin is a potent inducer of the cytochrome P450 hepatic enzyme system and can decrease the plasma concentrations and possibly the efficacy of ergocalciferol, Vitamin D2. In some cases, reduced concentrations of circulating vitamin D and 1,25-dihydoxy vitamin D have been accompanied by decreased serum calcium and phosphate, and elevated parathyroid hormone. Dosage adjustments of ergocalciferol, Vitamin D2 may be required.
Magnesium Citrate: (Major) Avoid vitamin D coadministration with magnesium citrate in persons on chronic hemodialysis due to the risk for hypermagnesemia.
Magnesium Hydroxide: (Major) Avoid vitamin D coadministration with magnesium hydroxide in persons on chronic hemodialysis due to the risk for hypermagnesemia.
Magnesium: (Major) Avoid vitamin D coadministration with magnesium-containing products, such as antacids, in persons on chronic hemodialysis due to the risk for hypermagnesemia.
Mineral Oil: (Moderate) Absorption of fat-soluble vitamins is reported to be decreased with prolonged oral administration of mineral oil. However, despite warnings in various texts, there is little direct evidence that the interaction is of practical/clinical importance with limited use as directed. It may be prudent for those taking dietary supplements of Vitamin A, D, E, or K to separate administration by 1 hour before or 4 hours after a mineral oil oral dosage to help limit absorption interactions. Theoretically, the effect on fat-soluble vitamin absorption may more likely occur with prolonged or chronic administration of mineral oil.
Orlistat: (Moderate) Administer vitamin E at least 2 hours before or after the administration of orlistat to limit effects on oral absorption. Orlistat has been shown to inhibit the absorption of a vitamin E acetate supplement by 60%. (Moderate) Orlistat reduced the absorption of fat-soluble vitamins during clinical trials. The bioavailability of orally administered vitamin D may also be decreased. In patients receiving orally-administered vitamin D with orlistat, close monitoring is recommended. In addition, the manufacturer recommends that fat-soluble vitamins be administered at least 2 hours before or after the administration of orlistat to limit effects on oral absorption.
Phosphorus: (Major) High intake of phosphates concomitantly with vitamin D or vitamin D analogs may lead to hyperphosphatemia. Dose adjustment of vitamin D or vitamin D analogs may be necessary during coadministration with phosphorus salts. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia.
Rifampin: (Moderate) Rifampin is a potent inducer of the cytochrome P450 hepatic enzyme system and can decrease the plasma concentrations and possibly the efficacy of cholecalciferol, Vitamin D3. In some cases, reduced concentrations of circulating vitamin D and 1,25-dihydoxy vitamin D have been accompanied by decreased serum calcium and phosphate, and elevated parathyroid hormone. Dosage adjustments of cholecalciferol, Vitamin D3 may be required. (Moderate) Rifampin is a potent inducer of the cytochrome P450 hepatic enzyme system and can decrease the plasma concentrations and possibly the efficacy of ergocalciferol, Vitamin D2. In some cases, reduced concentrations of circulating vitamin D and 1,25-dihydoxy vitamin D have been accompanied by decreased serum calcium and phosphate, and elevated parathyroid hormone. Dosage adjustments of ergocalciferol, Vitamin D2 may be required.
Selumetinib: (Moderate) Coadministration of selumetinib with supplemental vitamin E is not recommended if the total daily dose of vitamin E (amount in selumetinib plus the supplement) exceeds the recommended or safe daily limit; high dose vitamin E may increase the bleeding risk by antagonizing vitamin K dependent clotting factors and inhibiting platelet aggregation. Selumetinib contains 32 mg of vitamin E in the 10 mg capsules and 36 mg of vitamin E in the 25 mg capsules.
Thiazide diuretics: (Moderate) Dose adjustment of vitamin D or vitamin D analogs may be necessary during coadministration with thiazide diuretics. Additionally, serum calcium concentrations should be monitored frequently. Monitor more frequently in patients with a history of hypercalcemia. Hypercalcemia may be exacerbated by coadministration of vitamin D or vitamin D analogs and thiazide diuretics. Thiazide diuretics are known to induce hypercalcemia by reducing the excretion of calcium in the urine.
Tipranavir: (Major) Tipranavir should be used with caution in patients who may be at risk of increased bleeding, such as in patients taking high doses of vitamin E. In vitro, tipranavir was observed to inhibit human platelet aggregation at concentrations consistent with human exposure at regular doses. In rats, coadministration with vitamin E increased the bleeding effects of tipranavir.
Warfarin: (Moderate) Vitamin E should be used cautiously in patients receiving warfarin. While the mechanism is unclear, it is believed that concomitant administration of large doses of vitamin E (e.g., more than 400 units per day) with warfarin potentiates hypoprothrombinemia due to the vitamin K antagonistic activity of vitamin E.

Calcidol/Calciferol/Cholecalciferol/D3 Vitamin/Drisdol/D-Vita/Enfamil D-Vi-Sol/Ergocalciferol/UpSpring Baby Vitamin D3 Oral Drops: 0.025mL, 0.0394mL, 0.05mL, 0.1mL, 1mL, 400IU, 800IU, 1000IU, 5000IU, 8000IU
Cholecalciferol/DECARA/Deltalin/Dialyvite Vitamin D/Drisdol/Ergo D/Ergocalciferol/Happy Sunshine Vitamin D3/MAXIMUM D3/PureMark Naturals Vitamin D/Super Happy SUNSHINE Vitamin D3/Vitamin D (Cholecalciferol), Vitamin E (Alpha Tocopherol) Oral Cap: 1.25mg, 1000IU, 2000IU, 5000IU, 10000IU, 25000IU, 50000IU, 10000-5IU
Cholecalciferol/Dialyvite/Dialyvite Vitamin D3/Thera-D 2000/Thera-D 4000/Thera-D Rapid Repletion/THERA-D SPORT Oral Tab: 400IU, 1000IU, 2000IU, 4000IU, 5000IU, 50000IU
Cholecalciferol/Fiber with Vitamin D3 Gummies Gluten-Free/Replesta/Replesta Children's/YumVs/YumVs Kids ZERO/YumVs ZERO Oral Tab Chew: 400IU, 500IU, 1000IU, 2000IU, 5000IU, 14000IU, 50000IU

NOTE: The Tolerable Upper Intake Level (UL) is defined as the highest daily intake of a nutrient that is likely to pose no risk in otherwise healthy individuals. The ULs are not intended to apply to individuals with specific disease states. Maximum doses for other uses are indication specific.

Maintenance Tolerable Upper Intake Level (UL) is 100 mcg/day (4,000 International Units/day) PO.

Maintenance Tolerable Upper Intake Level (UL) is 100 mcg/day (4,000 International Units/day) PO.

Maintenance Tolerable Upper Intake Level (UL) is 100 mcg/day (4,000 International Units/day) PO.

Children 9 to 12 years: Maintenance Tolerable Upper Intake Level (UL) is 100 mcg/day (4,000 International Units/day) PO.
Children 4 to 8 years: Maintenance Tolerable Upper Intake Level (UL) is 75 mcg/day (3,000 International Units/day) PO.
Children 1 to 3 years: Maintenance Tolerable Upper Intake Level (UL) is 62.5 mcg/day (2,500 International Units/day) PO.

Infants 7 to 12 months: Maintenance Tolerable Upper Intake Level (UL) is 37.5 mcg/day (1,500 International Units/day) PO.
Infants 1 to 6 months: Maintenance Tolerable Upper Intake Level (UL) is 25 mcg/day (1,000 International Units/day) PO.

Maintenance Tolerable Upper Intake Level (UL) is 25 mcg/day (1,000 International Units/day) PO.

Both forms of vitamin D are metabolized to the active form, calcitriol (1,25-dihydroxyvitamin D); all vitamin D activity is due to this metabolite. Calcitriol promotes renal reabsorption of calcium, increases intestinal absorption of calcium and phosphorus, and increases calcium mobilization from bone to plasma. Calcitriol promotes intestinal absorption of calcium through binding to a specific receptor in the mucosal cytoplasm of the intestine. Subsequently, calcium is absorbed through formation of a calcium-binding protein. The synthesis of calcitriol is enhanced by elevated parathyroid hormone levels and low plasma phosphorus levels. Hypocalcemia causes release of parathyroid hormone, which stimulates the production of calcitriol.
The vitamin D receptor (VDR) is present in numerous tissues throughout the body; the exact action of calcitriol within these tissues is not completely understood. There is evidence that calcitriol plays a role in the immune system. Calcitriol has been shown to inhibit cancer growth and stimulate cell differentiation.

Vitamin D is administered orally. Maximal clinical effects of a given dosage are usually observed in 4 weeks. Dietary vitamin D is absorbed from the GI tract in the presence of bile salts and is initially bound to chylomicrons, then is slowly transferred to vitamin D binding protein (DBP) in the serum. The uptake by chylomicrons results in vitamin D update by adipose tissue and muscle; remaining vitamin D in circulation is then metabolized by the liver. The uptake by the liver and other tissues accounts results in a plasma half-life of 4 to 6 hours for supplemental vitamin D. However, studies have shown that the whole-body half-life is about 2 months due to the stores in these tissues.[52879]
 
Ergocalciferol and cholecalciferol are considered prohormones and are converted in the liver by a group of activating cytochrome P450 (CYP) enzymes, CYP2R1, CYO27A1, and CYP27B1, to 25-hydroxyvitamin D (25(OH)D, calcidiol), the predominant form of vitamin D in the blood. This metabolite has a half-life of about 15 days. Serum 25(OH)D concentrations increase in a non-linear fashion in response to increased vitamin D intake based on baseline concentrations and duration of supplementation. Increasing serum 25(OH)D levels to more than 50 nmol/L requires a greater amount of vitamin D than increasing baseline levels that are less than 50 nmol/L. The impact on serum 25(OH)D concentrations is less when doses are at least 25 mcg/day (1,000 International Units/day) compared to doses less than 25 mcg/day (1,000 International Units/day). For example, for vitamin D doses of at least 25 mcg/day (1,000 International Units/day), the increase in serum 25(OH)D concentrations is about 1 nmol/L for each 1 mcg (40 International Units) of vitamin D. Conversely, for vitamin D doses of 15 mcg (600 International Units) or less, the increase in 25(OH)D concentrations is about 2.3 nmol/L for each 1 mcg (40 International Units) of vitamin D.[52900] In the kidneys, 25-hydroxyvitamin D is further converted to its active, hormonal form, 1,25-dihydroxyvitamin D (1,25(OH)2D, calcitriol), which has a half-life of about 15 hours and accounts for only a small portion of the total body amount of vitamin D. Synthesis to this active form by renal CYP27B1 is tightly regulated by parathyroid hormone and serum phosphate levels.[52879] [52900] All metabolites of vitamin D are excreted through the bile into the feces; very little is excreted in the urine.

Vitamin D is well absorbed orally in most individuals without conditions associated with fat malabsorption. There is a time lag of 10 to 24 hours between the oral administration of vitamin D and the initiation of its action in the body due to the necessity of synthesis of the active metabolites in the liver and kidneys.

Adverse effects have not been reported with the normal daily intake of Vitamin D within the recommended dietary daily intakes for a pregnant female. Animal reproduction studies have shown fetal abnormalities in several species associated with hypervitaminosis D; therefore, the use of vitamin D in excess of the recommended dietary allowance during normal pregnancy should be avoided unless, in the judgment of the physician, potential benefits outweigh the hazards involved. The RDA of vitamin D during pregnancy is 15 mcg/day (600 International Units/day) with a Tolerable Upper Intake Limit of 100 mcg/day (4,000 International Units/day).

The 25-hydroxyvitamin D metabolite of vitamin D is distributed into human breast milk at concentrations relative to the maternal serum concentration. Typical breast milk concentrations (without maternal supplementation) are not sufficient to prevent vitamin D deficiency in infants that are exclusively breast-fed and do not receive other vitamin D supplementation. Prolonged, exclusive breast-feeding of infants without recommended vitamin D supplementation is a significant cause of rickets in infants, especially in dark-skinned infants breast-fed by mothers who are not vitamin D replete. Use of vitamin D within the recommended daily dietary intake for lactating women is generally recognized as safe. The recommended maternal daily allowance of vitamin D during breast-feeding is 600 International Units/day with a Tolerable Upper Intake Limit of 4000 International Units/day. While high-dose vitamin D supplementation to nursing mothers has been shown to increase the concentration of vitamin D in breast milk and favorably increase 25(OH)D levels in infants, the results have not been validated and supplementation to infants is still recommended. Generally, the serum calcium concentrations of the infant should be monitored when a nursing mother is prescribed vitamin D in high doses, since hypercalcemia has been reported with high dose maternal use.