Some observations on vitamin D3 metabolism in thyrotoxicosis
Velentzas, G.C.
Acta Vitaminologica et Enzymologica 5(3): 159-163
1983
ISSN/ISBN: 0300-8924 PMID: 6316771 Document Number: 197206
25-Hydroxycholecalciferol (25-HCC) was estimated in blood plasma of 4 healthy, euthyroid subjects and in 5 subjects with thyrotoxicosis before and at 6-h intervals after they were given 1 mg cholecalciferol by vein. In thyrotoxic subjects 25-HCC had increased after 6 h reaching a maximum between the 12th and 36th h and decreased thereafter. In euthyroid subjects 25-HCC started to increase after 96 h. Results indicate that hepatic hydroxylation of cholecalciferol is 2.5 to 8 times faster in thyrotoxic than in healthy subjects and may explain the variability in 25-HCC in plasma in thyrotoxicosis.