CALCITRIOL IS GIVEN BY MOUTH OR BY INTRAVENOUS INJECTION. USUAL INITIAL ADULT DOSES OF 250 NANOGRAMS DAILY OR ON ALTERNATE DAYS ARE GIVEN BY MOUTH, INCREASED IF NECESSARY, IN STEPS OF 250 NANOGRAMS AT INTERVALS OF 2 TO 4 WEEKS, TO A USUAL DOSE OF 0.5 TO 1 MICROGRAM DAILY. INITIAL DOSES INTRAVENOUSLY ARE USUALLY 500 NANOGRAMS THREE TIMES A WEEK INCREASED IF NECESSARY IN STEPS OF 250 TO 500 NANOGRAMS AT INTERVALS OF 2 TO 4 WEEKS, TO A USUAL DOSE OF 0.5 TO 3 MICROGRAMS THREE TIMES A WEEK. FOR MODERATE TO SEVERE SECONDARY HYPERPARATHYROIDISM IN DIALYSIS PATIENTS INITIAL DOSES OF 0.5 TO 4 MICROGRAMS HAVE BEEN GIVEN THREE TIMES A WEEK, INCREASED IF NECESSARY IN STEPS OF 250 TO 500 NANOGRAMS AT INTERVALS OF 2 TO 4 WEEKS TO A MAXIMUM OF 8 MICROGRAMS GIVEN THREE TIMES A WEEK. CALCITRIOL, MAY BE USED IN THE TREATMENT OF OSTEOPOROSIS . IN ESTABLISHED POSTMENOPAUSAL OSTEOPOROSIS, CALCITRIOL 0.25 MICROGRAMS TWICE DAILY IS RECOMMENDED . FOR PSORIASIS, ADULT AND CHILD OVER 12 YEARS, APPLY TWICE DAILY; NOT MORE THAN 35% OF BODY SURFACE TO BE TREATED DAILY, MAX. 30 G DAILY