Vitamin A concentration in mature human milk

To quantify vitamin A levels in mature milk of 196 nursing women who were treated at the Maternity School of Rio de Janeiro and to evaluate its correlation with sociodemographic variables and degree of nutrition knowledge.

To quantify retinol concentrations, 10 mL of mature milk were collected by manual expression of one breast, 2 hours after the last feed, in the morning period. Values below 1.05 µmol/L and 2.3 µmol/L were considered inadequate to meet satisfactory intake and to constitute vitamin A liver reserve, respectively. The following variables were also assessed: sex, age, familiar income, maternal education, basic sanitation conditions, number of people in the household, maternal age, prenatal care, and degree of nutrition knowledge.

Among the 196 lactating mothers analyzed, the average vitamin A concentration observed in mature milk was 1.76±0.85 µmol/L and prevalence of vitamin A deficiency was observed in 20.5% mothers. There was no significant difference between vitamin A levels in maternal milk and the variables socioeconomic status and nutrition knowledge. Only 38.9% of lactating women presented enough vitamin A concentrations in milk for the infants' liver reserves (2.3 µmol/L).

These findings reveal high prevalence of inadequate vitamin A nutritional status of mothers and infants, consistent with the national prevalence reported in women of childbearing age and Brazilian children, and that the intervention measures to fight this shortage should be extended to all pregnant and postpartum women, regardless of sociodemographic conditions and degree of nutrition knowledge, in order to improve the health of mother and child.