Breast milk provides inadequate amounts of vitamin B12 for predominantly breastfed Guatemalan infants.

Abstract

Vitamin B12 (B12) plays in an important role in the development and function of the brain and nervous system, and adequate B12 status is especially important for the normal development of infants. In previous research conducted in Guatemala City we reported a high prevalence of B12 deficiency in lactating women and their infants 3 and 12 months of age, and low B12 concentrations in breast milk. The objective of this study was to assess predictors of serum B12 concentration in predominantly breastfed Guatemalan infants including intake of B12 from breast milk and other foods. Serum B12, breast milk and other food intakes, anthropometry, morbidity and socioeconomic status were assessed in infants 6.7±0.6 months of age (n=127, 52% female) in peri-urban Guatemala City. Twenty-four percent of infants had deficient B12 status (serum B12 concentration<148 pmol/L) and 37% had marginal B12 status (148-220 pmol/L). Serum B12 concentrations were negatively correlated with infants' consumption of energy from breast milk (r=-0.37, p=0.001), and positively correlated with their total consumption of animal source foods, especially cow's milk (r=0.40, p=0.001). Based on previously analyzed breast milk B12 concentrations in a nearby community, breast milk provided<10% of the recommended daily B12 intake for this age. We conclude that there was a high prevalence of B12 deficiency in these Guatemalan infants by 6 months of age. Serum B12 was higher in infants consuming more cow's milk and lower in those consuming more breast milk.