Maternal nutrition, breast milk micronutrients and infant growth in rural Gambia The World Health Organization recommends exclusive breastfeeding for the first six months of an infant’s life. However, the evidence base to support the adequacy of breast milk with respect to infant micronutrient status, across the duration of exclusive breastfeeding, among women who enter pregnancy and lactation with a poor nutritional status is limited. The research presented in this thesis explores the relationship between maternal nutritional status, breast milk micronutrients and infant status in a rural sub-Saharan context. Existing evidence for associations between maternal dietary intake and nutritional status and breast milk micronutrient composition were systematically reviewed. Most effected by maternal nutrition were breast milk water-soluble vitamin concentrations (except for folic acid), fat-soluble vitamin concentrations were less influenced, and mineral concentrations were generally unaffected (except for iodine and selenium). Next, the impact of feeding practice on infant growth in rural Gambia was explored. In this population, where growth faltering across the first two years of life is endemic, exclusive breastfeeding to six months of age had limited benefit on infant growth. Finally, the impact of maternal multiple micronutrient supplementation on breast milk iodine, thiamin, riboflavin, vitamin B6 and B12 was explored. Supplementation during pregnancy positively influenced maternal status for all investigated micronutrients, and modestly increased breast milk iodine and riboflavin concentrations across the first six months of lactation. No effects on breast milk concentrations of thiamin, vitamin B6 or B12, and limited effect on infant postpartum status, were observed. The research presented in this thesis suggests that concentrations of breast milk micronutrients may be insufficient in settings where maternal micronutrient status is poor, with likely consequences for infant health. This research supports the need for interventions to improve the nutritional status of pregnant and lactating women in resource-poor settings alongside the promotion of exclusive breastfeeding for optimal health outcomes for infants as well as their mothers.

Kamilla Gehrt Eriksen, September 2017