Vitamin D metabolism in idiopathic infantile hypercalcemia.
A 9-month-old boy who had the mild form of idiopathic infantile hypercalcemia was observed for 18 months. During the initial hypercalcemic stage, the serum concentration of 25-hydroxyvitamin D was normal. Urinary levels of cyclic adenosine monophosphate (cAMP) were low, and the serum concentrations of the dihydroxyl metabolites of vitamin D were appropriate to the high serum calcium concentration, with low 1,25-dihydroxyvitamin D and relatively high 24,25- and 25,26-dihydroxyvitamin D levels. Throughout the study period, there was a close positive correlation between the magnitude of the urinary cAMP excretion and the serum level of 1,25-dihydroxyvitamin D. The results indicate that excessive vitamin D intake leading to high serum levels of 25-hydroxyvitamin D are not decisive factors in the pathogenesis of idiopathic infantile hypercalcemia.
D015650:24,25-Dihydroxyvitamin D 3; D015652:25-Hydroxyvitamin D 2; D002117:Calcitriol / Q000097:blood; D000242:Cyclic AMP / Q000378:metabolism; D004100:Dihydroxycholecalciferols / Q000097:blood; D004872:Ergocalciferols / Q000031:analogs & derivatives / Q000097:blood; D006801:Humans; D006934:Hypercalcemia / Q000378:metabolism*; D007223:Infant; D008297:Male; D010710:Phosphates / Q000097:blood; D010758:Phosphorus / Q000097:blood; D014807:Vitamin D / Q000378:metabolism*
D004100:Dihydroxycholecalciferols; D004872:Ergocalciferols; D010710:Phosphates; D014807:Vitamin D; D015652:25-Hydroxyvitamin D 2; D010758:Phosphorus; D015650:24,25-Dihydroxyvitamin D 3; D000242:Cyclic AMP; D002117:Calcitriol; C026032:25,26-dihydroxycholecalciferol