Serum levels of 1,25-(OH)2-vitamin D are not altered by long-term supplementation with alphacalcidol (1-OH-vitamin D3). A double-blind, placebo-controlled study.
The endogenous production of 1,25-(OH)2-vitamin D has been estimated to be 1.5 micrograms daily. Despite the use of alphacalcidol (1,25-(OH)2-vitamin D) during more than a decade the long-term effects of the serum levels of 1,25-(OH)2-vitamin D have been poorly investigated. When 1 microgram of alphacalcidol was given daily to 39 non-vitamin D deficient subjects in a double-blind, placebo-controlled study during 4 months no significant effects on the serum levels of 1,25-(OH)2-vitamin D or 25-(OH)-vitamin D were found. The treatment however induced a 50% increase in urinary excretion of calcium (p less than 0.01). In conclusion, long-term supplementation with a physiological dose of alphacalcidol does not influence the serum levels of 1,25-(OH)2-vitamin D, despite a marked effect on urinary calcium excretion.
Lind
L
L
Department of Internal Medicine, University Hospital, Uppsala.
Wengle
B
B
Sörensen
O H
OH
Ljunghall
S
S
D000328:Adult; D002117:Calcitriol / Q000097:blood*; D002118:Calcium / Q000097:blood / Q000652:urine*; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D006887:Hydroxycholecalciferols / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood
D006887:Hydroxycholecalciferols; D010281:Parathyroid Hormone; D002117:Calcitriol; D002118:Calcium; C008088:alfacalcidol