No evidence to link vitamin A supplementation with fewer baby deaths: Cochrane review
The present review identified 12 studies assessing 168,460 babies in which the intervention group was supplemented with vitamin A during the newborn period.
But researchers writing in the Cochrane database of systematic reviews stated analysis showed no significant reduction in infant deaths at six months of age following the intervention, with similar findings for infant deaths at 12 months of age.
“Given this finding, and the absence of a clear indication of the biological mechanism through which vitamin A could affect mortality; along with substantial conflicting findings from individual studies, conducted in settings with potentially varying levels of maternal vitamin A deficiency and infant mortality... additional research is warranted before a decision can be reached regarding policy recommendations for this intervention,” wrote academics from Toronto, Canada.
The area is of high interest because babies have very low levels of vitamin A stored in the liver at birth and are dependent on breast milk as a source of vitamin A during the first few months of life.
Therefore, maternal vitamin A deficiency may result in a deficiency among infants.
Vitamin A deficiency is considered a major public health problem in low and middle income countries and globally 9.8 million pregnant women are affected by night blindness - one of the major consequences. Night blindness affects 5.2 million preschool children globally, and an estimated 190 million have low serum retinol concentrations.
“The prevalence of low serum retinol concentrations among pregnant women is highest in South East Asia (17.3%), followed by Africa (13.5%),” stated the research team.
They added: “Given the high burden of death among children younger than five years of age in low and middle income countries, and the fact that mortality in infancy is a major contributory cause, it is critical to obtain sound scientific evidence of the effect of vitamin A supplementation during the neonatal period on infant mortality and morbidity.”
But according to the review, data from three studies for children born at full term did not show a statistically significant effect on the risk of infant mortality at six months in the vitamin A group compared with the control group.
Additional analysis of data for all infants from 11 studies also revealed no evidence of a significant reduction in the risk of infant mortality at six months among babies supplemented with vitamin A compared with the control.
“We observed similar results for infant mortality at 12 months of age with no significant effect of vitamin A compared with control. Limited data were available for the outcomes of cause-specific mortality and morbidity, vitamin A deficiency, anaemia and adverse events,” they added.
The researchers judged the quality of evidence as being high for the most important clinical outcomes.
Source: Cochrane Database of Systematic Reviews
“Neonatal vitamin A supplementation for the prevention of mortality and morbidity in term neonates in low and middle income countries”
Authors: Batool A Haider, et al.