Relationship between maternal and infant serum vitamin D levels in Jos, Plateau State, Nigeria: a cross-sectional study.

Introduction: there is growing interest in the link between maternal and infant vitamin D (VD) levels. Breast milk transmission and the fact that the mother and her child may share risk factors for VD, such as exposure to sunlight, diet, and sociocultural influences may impact VD status, the magnitude of which is largely unknown in our topical low-middle income setting. We assessed the connection between maternal and infant VD status including their correlates.

Methods: this cross-sectional study investigated 95 maternal-infant pairs in Jos. Mothers were interviewed using a questionnaire. Blood sampling and analysis of serum total 25 hydroxy VD were performed using the chemiluminescent immunoassay method. Maternal and infant VD levels were classified as VD deficient (VDD), VD insufficient (VDI), and VD sufficient (VDS). The mean maternal and infant VD were compared, and the Spearman correlation between them was assessed, a stepwise linear regression was also performed with infant vitamin D as a dependent variable. For all statistical analysis, p<0.05 was considered significant.

Results: the median maternal and infant VD was 29.68 ng/ml and 29.41 ng/ml, respectively. The mean infant VD (32.19 ± 10.61 ng/ml) was comparable to maternal VD (31.12 ± 12.94 ng/ml) (p=0.483), with a Spearman correlation coefficient of 0.3 (p=0.037). Maternal vitamin D (beta=0.539, duration of exclusive breastfeeding (beta=-3.490), and infant age (beta=1.655) were found to be significant independent predictors of infant vitamin.

Conclusion: beyond neonatal age, a significant positive relationship between maternal and infants´ VD levels exists and suggests that family-focused vitamin D intervention might be an effective public health approach in the tropical city of Jos.