Effect of routine prenatal supplementation on vitamin concentrations in maternal serum and breast milk

The aim of the present study was to assess the effect of multivitamin supplements and their different vitamin A sources on retinol concentrations in serum and colostrum milk of postpartum women.

This was a retrospective cross-sectional study composed of healthy postpartum women attending two Brazilian private maternity wards (N = 100). According to the type of multivitamin taken during pregnancy, the women were assigned to one of four groups: control group (CG; n = 25), formulation 1 (F1; n = 25), formulation 2 (F2; n = 25), and formulation 3 (F3; n = 25). Blood and colostrum samples were collected under fasting conditions and retinol was analyzed by high-performance liquid chromatography. Dietary vitamin A was assessed using a food frequency questionnaire. Retinol concentrations <20 μg/dL (<0.70 μmol/L) in serum and <60 μg/dL (2.10 μmol/L) in colostrum were considered indicative of vitamin A deficiency.

Of women in the control group, 12% (n = 3) presented serum retinol levels below the cut-off value for adequacy; this was not observed in the supplemented groups. Evaluating the retinol content in breast milk, supplemented groups F1 and F3 presented 4% (n = 1) of inadequacy cases, whereas F2 presented 40% (n = 10). The concentrations found in the F2 and F3 groups were statistically different (P < 0.05).

The use of multivitamin supplements containing vitamin A during pregnancy prevents vitamin A deficiency regardless of the source administered. In breast milk, supplementation with β-carotene provided a lower concentration of vitamin A compared with retinol.