[25-hydroxyvitamin D plasma levels in adults, neonates and their mothers]

25-hydroxyvitamin D (25 OH vit D) plasma levels were measured according to the method of Preece et al. in 2 groups of subjects. Group 1 consisted of 10 adult controls in whom 25 OH vit D levels were measured 11 times at 1 month intervals. Group 2 consisted of 93 mother-child pairs including 71 neonates with normal plasma calcium levels (group 2a) and 22 with hypocalcemia (group 2b). In mothers, 25 OH vit D levels (group 2a: 12 ng/ml +/- 6.4 SD, n = 71; group 2b: 9.5 ng/ml +/- 3.5 SD, n = 22) were lower than in controls (25.1 ng/ml +/- 7.9 SD). In neonates, 25 OH vit D levels were correlated with those of their mothers; however there was no significant difference in neonates with or without hypocalcemia (group 2a: means = 11.9 ng/ml +/- 6.1 SD, n = 71; group 2b: means = 10 ng/ml +/- 4.1 SD, n = 22). 25 OH vit D levels in adults of group 1 were significantly correlated with exposure to sunlight, while no significant correlation was found in the mothers-children pairs of group 2. These results confirm the relationship of 25 OH vit D plasma levels of neonates with their mothers' but do not support the concept of a relation between low plasma levels in mother and the occurrence of hypocalcemia in neonates.