Evolution of plasma 25-hydroxycholecalciferol (25 OHCC), serum immunoreactive parathyroid hormon (iPTH) and calcitonin (iCT) concentrations in very low-birthweight infants (VLBWI): 36

Abstract

There is a little information for the late evolution of 250HCC,iPTH and iCT levels in very lowbirthweight infants. Fourteen preterm neonates (gestational age 26-35 weeks) with a birthweight between 950 and 1300 g were studied. All infants were fed with breast milk for 30 days. 7 infants were later supplemented with a humanized formula while the other infants were still fed with breast milk. All infants were supplemented with 2400 UI of vitamin D2 per 24 hr from the tenth day of life. At the age of 30 days, mean ± SD plasma 25 OHCC was 7.8 ± 7.5 ng/ml (Normal=6-30ng/ml), serum iPTH:66±27 (N< 100 μlEq/ml) and all iCT values were undetectable (<150pg/ml). At the age of 60 days, serum iCT was also undetectable in all infants. Plasma 250HCC was similar in the supplemented infants (21±11ng/ml) and in the infants fed with breast milk (24±8 ng/ml). Serum iPTH was normal in the infants fed with breast milk (58±35μlEq/ml) but higher (p<0.05) in the supplemented infants (162±74μlEq/ml) with 5 values above 100μ1Eq/ml. Serum iPTH was not correlated with serum phosphorus (P) level or with P intake. At the age of 60 days, a negative correlation between serum iPTH levels and Calcium (Ca) intake was not observed for the total Ca intake but only for the Ca intake provided by breast milk (r=-0.70;p<0.05).These data suggest that : 1) The amount of vitamin D2 supplementation induces normal levels of 250HCC in VLBW infants 2) Secondary hyperparathyroidism occurs only in the infants supplemented with a formula 3) When feeding these VLBW infants, there is a dilemna between poor P intake and hyperparathyroidism.