Simple folic acid-iron supplements taken during pregnancy may be more effective than multiple vitamins in reducing the risk of low birth weight babies, according to a US study.
The study, funded by the US health department, was conducted in rural Nepal by researchers with the Johns Hopkins Bloomberg School of Public Health's Center for Human Nutrition (CHN).
CHN researchers gave almost 5000 pregnant Nepalese women one of the following daily supplements: folic acid, folic acid-iron, folic acid-iron-zinc or a multiple micronutrient supplement containing folic acid, iron and zinc and 11 other micronutrients. All participants received vitamin A, with a control group receiving vitamin A alone. Previous studies by CHN researchers showed that vitamin A reduces pregnancy-related deaths in Nepal.
The findings showed that supplementation with folic-acid iron reduced the incidence of low birth weight by 16 per cent and the multiple micronutrient supplements reduced low birth weight by 14 per cent. Folic acid-iron-zinc supplementation and folic acid supplementation alone had no significant effect on birth size.
Dr Parul Christian, principal investigator of the study, said the study provides important new information in the pursuit of a universal antenatal supplement in both the developing world and in disadvantaged populations in the United States.
"Micronutrient deficiencies during pregnancy may predispose mothers to losing their foetuses, having low birth weight newborns or infants who grow poorly. In rural Nepal alone, where more than 40 per cent of babies are born low birth weight, a widespread micronutrient supplementation programme could have a tremendous impact on the health and survival of millions of children," she explained.
Worldwide, 250 million low birth weight babies are born each year. Ninety per cent of these infants are born in developing countries where maternal micronutrient deficiencies are widespread.
"Our research work is aimed at trying to discern the right combinations of micronutrients that will maximise the health benefits to both mother and child," Dr Christian explained. "You have to consider the potential for negative interactions between micronutrients. Our study shows that more nutrients are not necessarily better."
While researchers are optimistic that they are making progress, Dr Christian said more work is needed to understand the health effects of antenatal micronutrient use among mothers before being widely adopted in the developing world.
'Effects of alternative maternal micronutrient supplements on low birth weight in rural Nepal: double blind randomized community trial' was published in the 15 March 2003 issue of the British Medical Journal.