Metabolic inactivation of vitamin D is enhanced in primary hyperparathyroidism.
1. The elimination half-time of 25-hydroxyvitamin D in plasma was estimated after intravenous injection of the radioactively labelled metabolite in seven patients with primary hyperparathyroidism before and after excision of a parathyroid adenoma. 2. The elimination half-time of 25-hydroxyvitamin D was significantly shortened in primary hyperparathyroidism and reverted towards normal after parathyroidectomy. 3. The increased metabolic clearance of 25-hydroxyvitamin D in primary hyperparathyroidism was accounted for by an increased excretion of vitamin D-derived inactivation products in the faeces. 4. Enhanced hepatic inactivation of 25-hydroxyvitamin D may be important in the development of vitamin D deficiency in primary hyperparathyroidism.
University Department of Medicine, Royal Infirmary, Manchester, U.K.
M R
MR
Clements
M
M
Davies
D R
DR
Fraser
G A
GA
Lumb
E B
EB
Mawer
P H
PH
Adams
D000368:Aged; D002112:Calcifediol / Q000037:antagonists & inhibitors* / Q000097:blood / Q000378:metabolism; D005243:Feces / Q000032:analysis; D005260:Female; D006207:Half-Life; D006801:Humans; D006961:Hyperparathyroidism / Q000097:blood / Q000378:metabolism* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D010280:Parathyroid Glands / Q000601:surgery
D002112:Calcifediol