Effects of 1,25 dihydroxyvitamin D3 administration on circadian mineral rhythms in humans.
1,25 Dihydroxyvitamin D3 (1,25(OH)2D3) (2.0 micrograms) was given intramuscularly to 6 healthy adult males. Twenty-four circadian patterns of blood-ionized calcium (Ca2+), serum phosphate (Pi), and total calcium (CaT) were assessed pre- and posthormone administration. Correlations of mean mineral rhythms with normative models were significant for each mineral pattern on both study days. Mean Ca2+ and CaT rhythms became weakly correlated after hormone treatment (r = .39). A small but statistically significant increment in the 24 h grand mean Ca2+ concentration was observed on the treatment day compared with the baseline day. However, this increment is less than the year-to-year variability in the grand mean mineral concentrations derived from the same subjects studied under baseline conditions previously. These data indicate that acute parenteral administration of near-physiological (2.0 micrograms) doses of 1,25(OH)2D3 appears to have no major effect on circadian mineral pattern shape or mean mineral concentrations.
D000328:Adult; D002117:Calcitriol / Q000494:pharmacology*; D002118:Calcium / Q000097:blood*; D002940:Circadian Rhythm / Q000187:drug effects*; D006801:Humans; D008297:Male; D008954:Models, Biological; D010281:Parathyroid Hormone / Q000097:blood; D010710:Phosphates / Q000097:blood*; D012016:Reference Values
D010281:Parathyroid Hormone; D010710:Phosphates; D002117:Calcitriol; D002118:Calcium