Vitamin B12 is Low in Milk of Early Postpartum Women in Urban Tanzania, and was not Significantly Increased by High dose Supplementation.

Omar N Lweno,Wafaie W Fawzi,Setareh Shahab-Ferdows,Ramadhani A Noor,Lindsay H Allen,Nahya Salim,Christopher R Sudfeld,Honorati Masanja,Karim P Manji,Ellen Hertzmark,Said Aboud

doi:10.3390/nu12040963

Abstract

The effect of maternal multivitamin supplementation on breast milk vitamin B12 concentrations has not been examined in Tanzania, where the prevalence of maternal plasma B12 insufficiency is 25.6%. Multivitamins (containing 50 µg vitamin B12) or placebo were provided during pregnancy and in the postpartum period. Breast milk samples were collected at or around six weeks postpartum from 491 participants in a trial of multivitamins (NCT00197548). Linear and logistic regression models were used to examine the effect of supplements on vitamin B12 concentration in milk and its associations with other variables including potential confounders. Median vitamin B12 concentration in breast milk was 206 pmol/L and 70% of women had levels indicating inadequacy (<310 pmol/L). Multivitamin supplements did not significantly reduce the odds of inadequate vitamin B12 in breast milk, suggesting suboptimal absorption. A single unit increase in maternal hemoglobin at six weeks was associated with 18% lower odds of inadequate vitamin B12 in breast milk. Participants with higher BMI at baseline had double the odds of having inadequate vitamin B12 than the reference group (<22 kg/m2). Trials to determine the optimal dose, route, and duration of supplementation to improve maternal B12 status in Sub-Saharan Africa are of utmost importance.

Highlights

Vitamin B12 deficiency is common in low- and middle-income settings, with reported prevalence ranging from 40% in South America to 60%–80% in some parts of Asia and Africa [1]
The inclusion criteria for the primary study were (1) human immunodeficiency virus (HIV)-negative pregnant women with a gestational age ranging from 12–27 weeks according to the date of the last menstrual period who attended study antenatal clinics between August 2001 and July 2004, (2) written informed consent to participate in the study, (3) a plan to stay in Dar es Salaam until delivery and for 1 year thereafter
We examined predictors of the continuous concentration of vitamin B12, and noted a similar trend, with an increase of 3.7% for every 1 unit (g/dL) increase in hemoglobin at 6 weeks postpartum

Summary

Introduction

Vitamin B12 deficiency is common in low- and middle-income settings, with reported prevalence ranging from 40% in South America to 60%–80% in some parts of Asia and Africa [1]. Longitudinal studies have demonstrated the progressive decline of breast milk vitamin B12 concentration during the first 3 months of lactation and by the 4th month of life the lower concentration of vitamin B12 in breast milk is associated with an increase in infant serum methylmalonic acid, which has been suggested as indicating that status is insufficient to maintain metabolic functions [7]. Several studies have demonstrated that women receiving vitamin B12 supplements have higher concentrations of plasma vitamin B12 during pregnancy [6,8], and the main predictor of vitamin B12 concentration in breast milk is maternal B12 status and stores during pregnancy [1]. Results from recent studies conducted in Kenya have shown that vitamin B12 concentrations in breast milk were not associated with reported dietary intake of vitamin B12, animal source food intake and household hunger [9]. Maternal supplementation with vitamin B12 has been reported to increase vitamin B12 in breast milk in India using a dose of 50 μg [6]

Methods

Discussion

Conclusion