[Decompensation of physiologic hypocalcemia in infants inducing vitamin D deficiency rickets]

43 infants taking the same dosage of vitamin D and calcium were investigated. The results showed that vitamin D deficiency rickets (VDR) were still present in some infants when vitamin D was sufficient, because of deficiency of 1,25-dihydroxyvitamin D (1,25-(OH)2D3). Serum calcium, phosphorus, alkaline phosphatase, triiodothyronine (T3), thyroxine (T4), calcitonin (CT), immunoreactive parathyroid hormone (iPTH), and 25-hydroxyvitamin D (25 OHD3) concentrations were compared among infants with normal, VDR of the early and recovering stages. The decompensation of physiological hypocalcemia in infants is probably the real cause of VDR and the decompensation is correlated closely with the development of parathyroid gland. This new concept is raised both at home and abroad. More practical methods for the treatment and prevention of VDR are suggested.