The effect of Vitamin B12 supplementation on Growth and Development in Nepali Infants

Rationale: Globally, vitamin B12 deficiency is one of the most common micronutrient deficiencies. The only relevant source of Vitamin B12 is animal-source foods. Vitamin B12 is crucial for normal cell division and is necessary for brain growth as well as for the maintenance of its normal function. Deficiency is also associated with impaired growth. In a previous study, we demonstrated that vitamin B12 administration over a period of six months enhanced growth, and scores on a neuro-developmental test in young Indian children. However, the overall effect was small and, for the developmental scores significant only in those that were malnourished at the start of the study. Our findings need to be verified in trials targeting younger, malnourished children and with longer supplementation time. Hypothesis : This proposed study will test three hypotheses; to measure to what extent 2 µg of vitamin B12 administration for one year to marginally stunted children improves; 1) growth, 2) neurodevelopment, and 3) hemoglobin concentration. Study design: Randomized placebo-controlled trial. Half of the children will receive a paste containing vitamin B12, the other half the same paste but without vitamin B12. Study and 600 In this population we have demonstrated that B12 deficiency and poor growth is common in early childhood. Data: The main outcomes of this study are scores on developmental assessments tools and growth measured every month for 12 months. We will also attempt to follow these children beyond the time of supplementation, i.e. beyond the period of this project to measure to what extent any neurodevelopmental changes persist after end of supplementation. Scientific basis: Globally, vitamin B12 deficiency is one of the most common micronutrient deficiencies. The only relevant source of vitamin B12 is animal-source foods. Vitamin B12 is crucial for normal cell division and differentiation and is necessary for the development and initial myelination of the central nervous system as well as for the maintenance of its normal function. Deficiency is also associated with impaired infant and child growth. In a previous clinical trial, we demonstrated that vitamin B12 administration over a period of six months enhanced growth and neurodevelopment in young Indian children. The overall effect on growth was significant but small. We saw an effect on both ponderal (weight for age z scores) and linear (height for age z scores) growth. However, the overall effects were driven by the effects in the subgroups of children who were wasted, underweight or stunted at baseline, and no effect in the children who were not malnourished at baseline. This effect modification was significant for all three (stunting, wasting, and underweight) baseline variables. Similarly, the effect of the intervention on neurodevelopmental scores was also strongest in the subgroup of children that were stunted. We have the years undertaken studies on dietary intake and status in women and children in Bhaktapur, Nepal. In this site, vitamin B12 deficiency is very common. The objective of the proposed study is to measure to what extent administration of 2 µg of vitamin B12 to stunted children from the last half of infancy and for 12 months affect neurodevelopment, growth and hemoglobin concentration.