The effect of vitamin B12 supplementation during pregnancy on infant growth and development
Vitamin B12 deficiency is highly prevalent in pregnant Indian women. This has been associated with an increased risk of adverse perinatal outcomes. Neuropsychological tests have shown an association between low maternal vitamin B12 status and poorer cognitive performances in the offspring, although findings from these studies have been inconsistent. Vitamin B12 has an important role in the formation of myelin which is important for the transmission speed of neural impulses and myelination in the central nervous system has been linked to cognition. Assessing neurophysiological measures using event-related potentials (ERPs) in children may provide additional information on the effect of maternal vitamin B12 supplementation on offspring brain function. However, few studies have investigated the burden and determinants of vitamin B12 status in young infants. A study was conducted in 2017 to determine the associations between maternal and infant vitamin B12 status. Pregnant women participating in a vitamin B12 supplementation trial in South India, were randomized to receive vitamin B12 (50 micro gram) or placebo supplementation daily during pregnancy through 6 weeks postpartum. All women received 60 milli gram of iron and 500 micro gram of folic acid daily during pregnancy, as per standard of care. This prospective analysis was conducted to determine the associations between maternal vitamin B12 biomarkers (that is, plasma vitamin B12, methylmalonic acid, and tHcy) during each trimester with infant vitamin B12 status at 6 weeks of age. The study concluded that impaired maternal vitamin B12 status, which combined both circulating and functional biomarkers, was the single best predictor of infant vitamin B12 status. Impaired maternal vitamin B12 status throughout pregnancy predicted a higher risk of vitamin B12 deficiency in infants, after adjusting for vitamin B12 supplementation. Future interventions are needed to improve vitamin B12 status periconceptionally, and to ensure optimal vitamin B12 status and health outcomes in pregnant women and their children.
Vitamin B12 is required for healthy infant growth and development, but low and marginal vitamin B12 status is endemic in low-income and middle-income countries. a community-based, double-blind, randomized, placebo-controlled trial was conducted in Nepal to determine the effect of vitamin B12 supplementation during pregnancy on infant growth and development. The study aimed to measure the effect of vitamin B12 supplementation from early pregnancy until 6 months post partum on infant growth and neurodevelopment.
The scientists randomly assigned 800 pregnant women (aged 20–40 years) who were up to 15 weeks pregnant-recruited from home visits and outpatient departments at three hospitals in Nepal-to daily supplementation with 50 micro gram oral vitamin B12 or placebo until 6 months postpartum. The study was double-blinded, that is, independent scientists generated the list that linked allocation to participants’ study identification number. Participants were masked to group assignment and all investigators were masked until data cleaning was completed. The primary outcomes were the length-for-age Z score at age 12 months and the cognitive composite score of the Bayley Scales of Infant and Toddler Development at age 6 months and 12 months. The primary and secondary outcomes, including adverse events, were also assessed in that study.
Although vitamin B12 deficiency was prevalent in the study population and vitamin B12 supplementation from early pregnancy substantially improved vitamin B12 status, supplementation did not improve infant growth or neurodevelopment. There was also no significant difference in infant haemoglobin concentrations despite a substantial biomarker response and improved vitamin B12 status among mothers and infants. This research findings support the current WHO recommendations of no routine vitamin B12 supplementation during pregnancy.
