Dietary intake and status of selenium in breast milk and serum of lactating mothers in Awka, South East Nigeria

Background: Selenium is an essential micronutrient for human growth and development. Breast milk is usually the primary source of this nutrient for infants which is fundamental for their healthy brain development; its deficiency can lead to severe neurocognitive outcomes. The concentration of selenium in breast milk is dependent on the maternal diet. Aim: This study assessed associations between maternal diet and levels of selenium concentrations in breastmilk and serum of 124 lactating mothers. Methods: Breast milk and serum samples were collected from lactating mothers whose breast-fed infant was at least one month old. A validated food frequency questionnaire was used to collect information on dietary intake. Descriptive statistics were used to summarize the data while paired t-test was used to determine any statistically significant differences between sample means. Spearman's rank correlation analysis was used to determine associations between breast milk and serum selenium concentrations and study variables. Results: Average time postpartum was 2.9 months while mean concentrations of selenium in breast milk and serum were 6.57 ± 2.69 and 68.48 ± 26.86 µg/L, respectively. Levels of selenium in breast milk and serum were deficient for more than half of the lactating mothers. No statistically significant associations were found between breast milk selenium concentration and time postpartum as well as maternal diet except for eggs (r = 0.23, p = 0.01). Conclusion: The evidence of deficient concentrations of breast milk selenium indicates a poor correlation with maternal diet and suggests the need for postpartum screening of breastfeeding mothers.