Subclinical hypovitaminosis D among exclusively breastfed young infants.

The objective was to determine Vitamin D status of mother-newborn diads at birth and of their exclusively breastfed (EBF) infants at 3 months. The design used was a longitudinal study. The methods used were exclusively breastfed infants born at term with birth weight greater than 2.5 kg to normal healthy mothers followed till 3 months. Serum calcium phosphorous heat labile alkaline phosphatase (HLAP) and 25(OH)D estimated in 42 mother / cord blood diads and in 35 (EBF) infants followed up at 3 months. Twenty five (OH)D less than 15 ng/mL was considered low and 15 to 25 ng/mL low to normal. Ca P HLAP were significantly higher in cord blood (P less than 0.001) but mean 25 (OH)D 19.36 ng/mL was comparable to maternal level of 22.9 ng/mL (r = 0.82 P less than 0.001). At 3 months only HLAP was significantly higher compared to cord blood. Higher 25 (OH)D at 3 months correlated with higher 25 (OH)D values in cord blood (r = +0.616 P less than 0.001) as well as higher antenatal maternal levels (r = + 0.552 P less than 0.001). Serum 25 (OH)D values less than 25 ng/mL was observed in 50% mothers 62% cord blood specimens and 80% infants at 3 months. Subnormal maternal vitamin D status is associated with vitamin D deficiency in newborns and persists in exclusively breastfed infants. (authors)