In a recent study published in The Lancet, researchers evaluated the results of maternal vitamin B12 (cyanocobalamin) supplementation on the neurodevelopment and growth of infants born in Nepal.

Study: The effect of vitamin B12 supplementation while pregnant on infant growth and development in Nepal: a community-based, double-blind, randomised, placebo-controlled trial. Image Credit: NatchaS/Shutterstock.com

Background

Children born in low- and middle-income nations may not attain full growth and neurodevelopment as a consequence of the prevalence of low or marginal cyanocobalamin levels within the blood.

Cyanocobalamin is critical for various physiological processes within the human body, especially neurological functions. 

Cyanocobalamin is particularly essential during gestation and early infancy to enhance pregnancy outcomes and enhance the expansion and neurodevelopment of infants.

Assessing neurological outcomes amongst infants following cyanocobalamin administration to moms while pregnant could inform decision- and policy-making concerning antenatal care.

Concerning the study

In the current study, researchers investigated whether administering vitamin B12 supplements to moms from the initial gestational period till six months post-delivery could improve neurodevelopment outcomes in neonates born in Nepal.

The double-blinded, community-based, placebo-controlled clinical trial included 800 expecting women, 20.0 to 40.0 years of age, who had accomplished a maximum of 15.0 weeks of gestation.

The participants were randomly assigned in a 1:1 ratio (1:1) to receive 50.0 μg of oral cyanocobalamin every day (intervention group, n=400) or a placebo (placebo group, n=400) until six months post-delivery.

The participants were recruited from home visits and outpatient health departments of three Nepali hospitals between March 28, 2017, and October 15, 2020. Scientists generated the allocation list independently, linking the participants’ personal identification numbers.

The participants and investigators were blinded to the intervention, and the participants were followed up through May 18, 2022. Serum samples were obtained from the participants to measure vitamin B12 levels, expressed as pmol/L.

The first study outcomes were the linear growth, evaluated using the length-for-age Z scores (LAZ) at one 12 months of age 12, and neurodevelopment, evaluated using the Bayley Scales of Infant and Toddler Development, third edition (Bayley-III) cognitive composite scores of six months and one 12 months of age.

Secondary outcomes included stillbirths, infant deaths, and opposed events (AEs). The team assessed the study outcomes among the many intention-to-treat (ITT) sampled population.

Stillbirths, miscarriages, infant births lost to follow-up, and people born to moms who selected to discontinue were excluded from the evaluation. As well as, individuals were excluded from consequence evaluation at six months of age as a consequence of infant birth outside of the window period or if their moms were unwilling to travel as a consequence of the COVID-19 pandemic.

Results

At study initiation, 569 women (71.0%) had serological vitamin B12 levels of lower than 221.0 pmol/L, indicative of marginal or low vitamin B12 status.

Within the intervention group, out of 400 women, 23 were lost to follow-up, three women refused to proceed, 19 women had miscarriages or medical termination of pregnancy, and 377 live births were reported.

Within the placebo group of 400 women, 17 women were lost to follow-up, one woman refused to proceed, eight women had miscarriages or their pregnancy was medically terminated, and 383 live births were reported.

In each groups, 47 participants (6.0%) were lost to follow-up, largely as a consequence of spontaneous abortions or medical termination of pregnancy. Infant deaths or stillbirths were observed for 3 (1.0%) and nine (2.0%) women within the intervention and placebo groups, respectively.

Vitamin B12 supplementation didn’t significantly affect the first study outcomes, despite considerable improvements in serological vitamin B12 levels amongst moms.  

The mean length-for-age Z scores obtained at one 12 months of age were -0.570 and -0.550 for the intervention (366 neonates) and placebo groups (363 neonates), respectively, with a 0.020 difference within the mean.

The mean Bayley-III scores were barely greater amongst vitamin B12-treated participants (97.70, 364 infants) than amongst placebo-treated participants (97.10, 361 infants), with a 0.50 difference within the mean.

Conclusions

Overall, the study findings showed that despite vitamin B12 being deficient amongst Nepali pregnant women and the considerable improvement in serological vitamin B12 levels following vitamin B12 administration to moms between early pregnancy and 6 months post-delivery, the supplementation of vitamin B12 (50.0 μg vitamin B12 every day) didn’t significantly improve neonatal growth and development.

The study findings underpin the present antenatal pregnancy guidelines published by the World Health Organization (WHO) of no regular supplementation of vitamin B12 to moms in the course of the gestational period.