Infant Serum and Maternal Milk Vitamin B-12 Are Positively Correlated in Kenyan Infant-Mother Dyads at 1–6 Months Postpartum, Irrespective of Infant Feeding Practice1–3

• Authors: Anne Williams, Emory University; Christine P Stewart, University of California, Davis; Setareh Shahab-Ferdows, University of California, Davis; Daniela Hampel, University of California, Davis; Marion Kiprotich, Innovations for Poverty Action; Beryl Achando, Innovations for Poverty Action; Audrie Lin, University of California Berkeley; Clair A Null, Innovations for Poverty Action; Lindsay H Allen, University of California, Davis; Caroline J Chantry, University of California, Davis
• Journal Title: Journal of Nutrition and Food Sciences
• Volume: Volume 148, Number 1
• Publisher: OMICS International | 2018-01-01, Pages 86-93
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.1093/jn/nxx009
• Subjects: Health Sciences, Public Health; Health Sciences, Nutrition
• Keywords: vitamin B-12; human milk; micronutrient deficiency; infant feeding; breastfeeding; lactation; Kenya

Abstract

Background Vitamin B-12 is an essential nutrient required for many functions including DNA synthesis, erythropoiesis, and brain development. If maternal milk vitamin B-12 concentrations are low, infants may face elevated risks of deficiency when exclusively breastfed. Objective We evaluated cross-sectional associations between infant serum vitamin B-12 concentrations and maternal milk vitamin B-12 concentrations at 1–6 mo postpartum among an unsupplemented population in rural western Kenya, and assessed biological demographic, and dietary characteristics associated with adequate infant serum vitamin B-12. Methods We modeled 1) infant serum vitamin B-12 using maternal milk vitamin B-12 concentration with linear regression; and 2) adequate (>220 pmol/L) infant serum vitamin B-12 using hypothesized biological, demographic, and dietary predictors with logistic regression. In both models, we used generalized estimating equations to account for correlated observations at the cluster-level. Results The median (quartile 1, quartile 3) infant serum vitamin B-12 concentration was 276 pmol/L (193, 399 pmol/L) and approximately one-third of infants had serum vitamin B-12 ≤220 pmol/L, indicating that they were vitamin B-12 depleted or deficient. There was a positive correlation between maternal milk and infant serum vitamin B-12 (r = 0.36, P < 0.001) and in multivariable analyses, maternal milk vitamin B-12 concentration was significantly associated with infant serum vitamin B-12 adequacy (P-trend = 0.03). Conclusions Despite a high prevalence (90%) of maternal milk vitamin B-12 concentrations below the level used to establish the Adequate Intake (<310 pmol/L), there was a low prevalence of infant vitamin B-12 deficiency. We found few factors that were associated with infant vitamin B-12 adequacy in this population, including infant feeding practices, although maternal vitamin B-12 status was not measured. The contribution of maternal milk to infant vitamin B-12 status remains important to quantify across populations, given that maternal milk vitamin B-12 concentration is modifiable with supplementation. This trial was registered at clinicaltrials.gov as NCT01704105.