title: Serum concentrations of 25-hydroxyvitamin D in rickets of extremely premature infants.
abstract: Nine premature infants developed radiographic and biochemical rickets at a mean +/- SD of 12.6 +/- 2.8 weeks of age. Serum 25-hydroxyvitamin D concentrations were all low, with a mean of less than 3.6 +/- 2.1 ng/ml. The mean average daily intake of vitamin D since birth had been 300 +/- 181 IU, and the mean average daily intake during the week of diagnosis was 587 +/- 313 IU. All of the infants were extremely premature (mean weight 948 +/- 153 gm, mean gestation 27.7 +/- 1.1 weeks), and were being fed either a low-calcium "human milk-like" formula or a soy formula. It is postulated that low-calcium intake may have increased 25-OHD utilization in the face of a decreased ability of the extremely premature infant to produce 25-OHD. Because of multiple factors leading to both decreased production and possible increased utilization of 25-OHD, such infants have an increased requirement for vitamin D to maintain normal serum 25-OHD concentrations, and daily intakes of at least 400 IU vitamin D orally must be assured. Serum 25-OHD measurements and radiographs may be important in following infants at risk.
mesh_terms: D006801:Humans; D006887:Hydroxycholecalciferols / Q000097:blood* / Q000378:metabolism; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007235:Infant, Premature, Diseases / Q000097:blood* / Q000473:pathology / Q000628:therapy; D009751:Nutritional Requirements; D011859:Radiography; D012272:Ribs / Q000473:pathology; D012279:Rickets / Q000097:blood* / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology; D014807:Vitamin D / Q000627:therapeutic use
chemical_list: D006887:Hydroxycholecalciferols; D014807:Vitamin D