DialysisPO 0.25 mcg/day. If all unsatisfactory response, increase dose by 0.25 mcg/day at 4- to 8-wk intervals. Obtain serum calcium levels at least twice weekly during this titration. If hypercalcemia occurs, immediately discontinue treatment until normocalemia is obtained. Normal or only slightly reduced calcium levels may respond to dosages of 0.25 mcg every other day.
IV 0.02 mcg/kg (1 to 2 mcg) 3 times/wk, every other day. May increase 0.5 to 1 mcg, every 2 to 4 wk. During this titration, obtain serum calcium levels twice weekly.
Adults and Children (older than 3 years of age):PO Initial dosage is 0.25 mcg/day in adults and children older than 3 yr of age. Dosage may be increased up to 0.5 mcg/day.
Children younger than 3 years of age:PO 10 to 15 mg/kg/day.
HypoparathyroidismPO Initial dosage is 0.25 mcg/day in the morning. If unsatisfactory response, increase dose at 2- to 4-wk intervals. During this titration, obtain serum calcium levels 2 times/wk. If hypercalcemia occurs, immediately discontinue treatment until normocalemia is obtained.
Adults and children (6 yr of age and older):PO 0.5 to 2 mcg daily.
Children (1 to 5 yr of age):PO Usually given 0.25 to 0.75 mcg daily.
Adults:Topical Apply to affected areas twice daily, morning and evening (max, 200 g/week).
Supply of vitamin D depends mainly on exposure to UV rays of the sun for conversion of 7-dehydrocholesterol in the skin to vitamin D3 (cholecalciferol). Vitamin D3 is activated in the liver and kidney before fully active as a regulator of calcium and phosphorus metabolism at target tissues. The mechanism of action in the treatment of psoriasis has not been established.