24-25-dihydroxyvitamin-d-3 and Hypothyroidism

The circulating concentrations of calcium, phosphorus, and vitamin D metabolites were measured in 25 infants (fifteen to 30 days of age) with congenital hypothyroidism before treatment or during the first 6 months of thyroxine therapy. Five of the children before treatment and four during the early 3 months of treatment had mild hypercalcemia (10.8 to 12.4 mg/dl). Hypercalcemia before treatment did not appear to be related to the vitamin D status of the infant nor to an alteration in vitamin D metabolism, but to the presence of a residual thyroid secretion. In contrast, hypercalcemia during thyroxine therapy was related to vitamin D supplementation, even though the serum calcium concentration could not be correlated with the circulating concentration of any of the vitamin D metabolites assayed and obvious changes in vitamin D metabolism could not be demonstrated.

Topics: 24,25-Dihydroxyvitamin D 3; 25-Hydroxyvitamin D 2; Alkaline Phosphatase; Calcitriol; Calcium; Congenital Hypothyroidism; Dihydroxycholecalciferols; Ergocalciferols; Humans; Hypercalcemia; Hypothyroidism; Infant, Newborn; Phosphorus; Thyroid Hormones; Thyrotropin; Thyroxine; Time Factors; Vitamin D

Topics: 24,25-Dihydroxyvitamin D 3; Animals; Biological Transport, Active; Calcifediol; Calcitriol; Calcium; Dihydroxycholecalciferols; Hydroxycholecalciferols; Hypothyroidism; Intestinal Absorption; Male; Phosphates; Rats; Vitamin D