vitamin D (Drisdol, Calciferol, cholecalciferol, 1,25-Dihydroxycholecalciferol, ergocalciferol)
Classes: Vitamins, Fat-Soluble
Dosing and uses of Drisdol, Calciferol (vitamin D)
Adult dosage forms and strengths
1 mcg = 40 international units (IU)
oral solution
- 8000IU/mL (200mcg/mL)
capsule
- 50,000IU (1.25mg)
tablet
- 400IU (10mcg)
- 2000IU (50mcg)
Nutritional Supplementation
Recommended daily allowance (RDA)
19-70 years: 600 IU (15 mcg)/day
Pregnant or lactating women: 600 IU (15 mcg)/day
Osteoporosis
Prophylaxis and treatment
>50 years: 800-1000 IU (20-25 mcg) PO once daily with calcium supplements
Hypoparathyroidism
50,000-200,000 IU (0.625-5 mg) PO once daily with calcium supplements
Vitamin D-Resistant Rickets
12,000-500,000 IU (0.3-12.5 mg) PO once daily
Familial Hypophosphatemia
10,000-60,000 IU (0.25-1.5 mg) PO once daily with phosphate supplements
Pediatric dosage forms and strengths
1 mcg = 40 IU
oral solution
- 8000IU/mL (200mcg/mL)
capsule
- 50,000IU (1.25mg)
tablet
- 400IU (10mcg)
- 2000IU (50mcg)
Nutritional Supplementation
RDA
0-12 months: 400 IU (10 mcg) PO once daily
1-18 years: 600 IU (15 mcg) PO once daily
Vitamin D-Resistant Rickets
12,000-500,000 IU (0.3-12.5 mg) PO once daily
Familial Hypophosphatemia
40,000-80,000 IU (1-2 mg) PO once daily with phosphate supplements; may be reduced after stage of growth is complete
Geriatric dosage forms and strengths
Nutritional Supplementation
RDA
<70 years: 600 IU (15 mcg) PO once daily
>70 years: 800 IU (20 mcg) PO once daily
Drisdol, Calciferol (vitamin D) adverse (side) effects
Frequency not defined
Arrhythmias
Confusion
Constipation
Dry mouth
Headache
Hypercalcemia
Lethargy
Metallic taste
Muscle or bone pain
Nausea
Sluggishness
Vomiting
Warnings
Contraindications
Hypercalcemia
Hypervitaminosis d
Ergocalciferol (oral): Gastrointestinal (GI), liver, or biliary disease associated with malabsorption of vitamin D analogues
Documented hypersensitivity with drugs that could have allergenic crossreactivity with ergocalceferoL
Cautions
Ergocalciferol: Use with caution in renal impairment (strong caution), heart disease, kidney stones, arteriosclerosis
Obtain serum calcium twice weekly during titration
Discontinue if patient becomes hypercalcemic
Presence of tartrazine in some products may cause allergic reactions
Vitamin D toxicity may last ≥2 months after therapy is discontinued
Restrict intake in infants with idiopathic hypercalcemia
Concurrent use of cardiac glycosides
Adequate clinical response to vitamin D therapy is dependent on adequate dietary calcium
Maintain normal serum phosphorous concentrations in patients treated for hyperphosphatemia to prevent metastatic calcification
When treating hypoparathyroidism, concomitant treatment with intravenous calcium, parathyroid hormone, and/or dihydrotachysterol may also be required
Adults with a body mass index (BMI) greater than 30 kg/m² are at high risk for vitamin D deficiency due to storage of vitamin D in adipose tissue; doses higher than recommended daily allowance may be required, but must be carefully monitored to avoid toxicity
Metabolism of vitamin D may be altered in patients with chronic kidney disease
In renal impairment, supplementation with ergocalciferol may be necessary; monitor closely
In patients with rickets, the range between therapeutic and toxic doses is narrow in vitamin D–resistant patients; adjust dose based on clinical response to avoid toxicity
Pregnancy and lactation
Pregnancy category: C (ergocalciferol)
Lactation: Drug is distributed into breast milk; use with caution
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Drisdol, Calciferol (vitamin D)
Mechanism of action
Stimulates calcium and phosphate absorption from small intestine; stimulates phosphate resorption at renal tubule; stimulates secretion of calcium into blood from bone
Absorption
Peak effect: 1 month with daily dosing
Metabolism
Metabolized in liver
Elimination
Excretion: Urine
