Hypoparathyroidism in pregnancy; osteomalacia & rickets. Treatment & prevention of vit D deficiency states & hypocalcemia in disorders eg, hypoparathyroidism; osteoporosis in conjunction w/ Ca. Prevention of corticosteroid-induced osteoporosis; fractures; various CV, metabolic disorders including DM, multiple sclerosis & malignant disorders.
Severe vit D deficiency (<10 ng/mL or <25 nmol/L) Loading dose: 50,000 IU once wkly for 2-3 mth. Maintenance dose: 800-2,000 IU once daily. Vit D deficiency (10-15 ng/mL or 25-37 nmol/L) or insufficiency (15-30 ng/mL or 37-75 nmol/L) 2,000-5,000 IU once daily or 5,000 IU once daily.
Patients w/ calculi or heart disease. Control plasma phosphate conc during therapy (risk of ectopic calcification). Monitor plasma Ca conc regularly. Monitor dose by testing for serum vit D level. Renal impairment. Pregnancy & lactation. Infants.
Increased risk of hypercalcemia w/ thiazide diuretics, Ca or phosphate. Increased vit D requirements w/ some antiepileptics eg, carbamazepine, phenobarb, phenytoin & primidone. Effectiveness may be reduced w/ rifampicin & INH. Effect may be counteracted by corticosteroid.