Association between oral supplementation with vitamin B12 during pregnancy and early lactation and maternal and infant measures of vitamin B12 status
Low vitamin B12status is associated with higher risk of multiple adverse pregnancy outcomes such as anaemia, gestational hypertension, preterm labour or delivery of infants with low birth weight (LBW), intrauterine growth retardation (IUGR) or neural tube defects. A study published in the American Society of Nutrition aimed to investigate the impact of daily oral vitamin B12supplementation during pregnancy and early lactation on maternal and infant measures of vitamin B12 status.
Duggan et al. conducted the randomised, double-blind, placebo-controlled trial in which 366 pregnant women (<14 weeks of gestation) were enrolled. All women were randomised to receive either daily oral vitamin B12supplementation (50 µg) (n=183) or placebo (no supplementation) (n=183) for a period of 6 weeks postpartum. Iron and folic acid supplements were administered throughout pregnancy.
At the end of the study period, compared with placebo, the supplemented women had significantly higher level of plasma vitamin B12concentrations at both second (216 pmol/L vs. 111 pmol/L) and third trimesters (184 pmol/L vs. 105 pmol/L), significantly higher median breast milk concentration of vitamin B12at 6 weeks postpartum (136 pmol/L vs. 87 pmol/L) and lower incidence of infants being born with IUGR (25% vs. 34%). Higher median
vitamin B12plasma concentrations as well as lower methylmalonic acid and homocysteine levels were observed in a subset of infants tested at the age of 6 weeks in the vitamin B12group.
The study was limited by a small sample size, inability to detect differences in birth outcomes and inability to assess vitamin B12 status in all infants.
The study concluded that oral vitamin B12supplementation during pregnancy and early lactation markedly improves the vitamin B12 status of mothers and infants. However, further investigations need to be conducted to determine the implications of this finding on neurologic and metabolic functions.
News Source: Duggan C, Srinivasan K, Thomas T, et al. Vitamin B-12 Supplementation during Pregnancy and Early Lactation Increases Maternal, Breast Milk, and Infant Measures of Vitamin B-12 Status. Journal of Nutrition. 2014;144(5):758-764.