B-vitamin interventions for women and children in low-income populations.

PURPOSE OF REVIEW: This review examines the effect of B vitamins on women and child health from recent evidence available.

RECENT FINDINGS: Findings were related to functional outcomes. In terms of foetal growth, although supplementation with B12 increased B12 status of nonpregnant and pregnant women and infants, maternal plasma homocysteine, which is related to multiple deficiencies of vitamin B12, B6, riboflavin or folate, has been shown to be associated with lower birth size rather than solely plasma B12. However, an experimental study with thiamine supplementation showed improvement in status in thiamine-deficient mothers and breast milk concentration, but not in infant status. Given the multiple aetiology of anaemia, the use of multiple micronutrient fortification has expectedly shown a reduction in anaemia prevalence in women. Furthermore, these micronutrients can interact with each other: high maternal folate intakes coupled with low B12 intakes were associated with a higher risk of delivering a small-for-gestational age infant. A high maternal plasma folate was also associated with insulin resistance in children aged 9.5 and 13.5 years.

SUMMARY: Interventions with B vitamins were found to be efficacious in improving the status in women and children. In multiple micronutrient supplementation programmes, the optimum composition of the supplement needs to be determined. The deleterious effect of high folate intakes with low B12 intakes needs to be explored further.