Hypercalcemia in infants with congenital hypothyroidism and its relation to vitamin D and thyroid hormones.
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.
D015650:24,25-Dihydroxyvitamin D 3; D015652:25-Hydroxyvitamin D 2; D000469:Alkaline Phosphatase / Q000097:blood; D002117:Calcitriol / Q000097:blood; D002118:Calcium / Q000097:blood; D003409:Congenital Hypothyroidism; D004100:Dihydroxycholecalciferols / Q000097:blood; D004872:Ergocalciferols / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000097:blood / Q000627:therapeutic use; D006801:Humans; D006934:Hypercalcemia / Q000097:blood / Q000150:complications*; D007037:Hypothyroidism / Q000097:blood / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy; D007231:Infant, Newborn; D010758:Phosphorus / Q000097:blood; D013963:Thyroid Hormones / Q000097:blood*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000008:administration & dosage / Q000627:therapeutic use; D013997:Time Factors; D014807:Vitamin D / Q000378:metabolism*
D004100:Dihydroxycholecalciferols; D004872:Ergocalciferols; D013963:Thyroid Hormones; D014807:Vitamin D; D015652:25-Hydroxyvitamin D 2; D010758:Phosphorus; D015650:24,25-Dihydroxyvitamin D 3; D013972:Thyrotropin; D000469:Alkaline Phosphatase; D002117:Calcitriol; D013974:Thyroxine; D002118:Calcium