Vitamin B-12 supplementation during pregnancy and early lactation increases maternal, breast milk, and infant measures of vitamin B-12 status.
What this study found
Vitamin B-12 supplementation improved maternal, breast milk, and infant vitamin B-12 status, but it did not clearly improve birth outcomes. In the vitamin B-12 group, median maternal plasma B-12 was higher than placebo in the second trimester (216 vs 112 pmol/L, P < 0.001) and third trimester (184 vs 105 pmol/L, P < 0.001), and breast milk B-12 at 6 weeks postpartum was higher (136 vs 87 pmol/L, P < 0.0005). Infant status also improved at 6 weeks, with higher plasma B-12 (199 vs 139 pmol/L, P < 0.001) and lower MMA (0.09 vs 0.16 mmol/L, P = 0.022) and homocysteine (10.9 vs 21.0 mmol/L, P <…
- Study & population
- Randomized, double-blind, placebo-controlled trial in pregnant women aged at least 18 years in urban Bangalore, India.
- Intervention
- Oral vitamin B-12 50 mg daily from enrollment through 6 weeks postpartum, compared with placebo.
- Key limitation
- Biochemical follow-up sample sizes were smaller than the randomized cohort, especially for infant and breast milk measures, which may limit precision.
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Open PDFOriginal abstract
Pregnant women in resource-poor areas are at risk of multiple micronutrient deficiencies, and indicators of low vitamin B-12 status have been associated with adverse pregnancy outcomes, including anemia, low birth weight, and intrauterine growth retardation. To evaluate whether daily oral vitamin B-12 supplementation during pregnancy increases maternal and infant measures of vitamin B-12 status, we performed a randomized, placebo-controlled clinical trial. Pregnant women <14 wk of gestation in Bangalore, India, were randomly assigned to receive daily oral supplementation with vitamin B-12 (50 μg) or placebo through 6 wk postpartum. All women were administered iron and folic acid supplements throughout pregnancy. One hundred eighty-three women were randomly assigned to receive vitamin B-12 and 183 to receive placebo. Compared with placebo recipients, vitamin B-12-supplemented women had significantly higher plasma vitamin B-12 concentrations at both the second (median vitamin B-12 concentration: 216 vs. 111 pmol/L, P < 0.001) and third (median: 184 vs. 105 pmol/L, P < 0.001) trimesters. At 6 wk postpartum, median breast milk vitamin B-12 concentration was 136 pmol/L in vitamin B-12-supplemented women vs. 87 pmol/L in the placebo group (P < 0.0005). Among vitamin B-12-supplemented women, the incidence of delivering an infant with intrauterine growth retardation was 33 of 131 (25%) vs. 43 of 125 (34%) in those administered placebo (P = 0.11). In a subset of infants tested at 6 wk of age, median plasma vitamin B-12 concentration was 199 pmol/L in those born to supplemented women vs. 139 pmol/L in the placebo group (P = 0.01). Infant plasma methylmalonic acid and homocysteine concentrations were significantly lower in the vitamin B-12 group as well. Oral supplementation of urban Indian women with vitamin B-12 throughout pregnancy and early lactation significantly increases vitamin B-12 status of mothers and infants. It is important to determine whether there are correlations between these findings and neurologic and metabolic functions. This trial was registered at clinicaltrials.gov as NCT00641862.