Vitamin A supplements can save the lives of children in low- and middle-income countries, a new review suggests.

The evidence is so strong that it would be unethical to continue comparing the supplements to placebo, say researchers who analyzed the findings of 43 randomized trials involving more than 215,000 children aged six months to five years.

Vitamin A must be obtained from the diet. It helps form and maintain healthy skin, teeth, skeletal and soft tissue, mucus membranes, and skin, according to the U.S. National Institute of Health.

Vitamin A was associated with reducing mortality in children by 0.76 times.

"Comparable with previous reviews, this review shows that vitamin A supplementation is associated with large and important reductions in mortality for children in low- and middle-income countries," Dr. Evan Mayo-Wilson of the Centre for Evidence-Based Intervention at the University of Oxford and his co-authors wrote in this week's issue of the British Medical Journal.

"This adds substantively to previous reviews in providing a plausible pathway and indicating that vitamin A supplementation reduces the incidence of and mortality from diarrhea and measles."

The World Health Organization estimated that as many as 190 million children younger than five may be vitamin A deficient globally.

Reducing deaths with vitamin A supplements in these children could equate to more than 600,000 lives saved each year, the researchers estimated.

Reducing deaths further

In a journal editorial accompanying the research, Andrew Thorne-Lyman and Wafaie Fawzi from the Harvard School of Public Health in Boston supported the recommendation for vitamin A supplementation, saying that although more research is needed in how to more effectively provide supplementation to those who need it, placebo trials are no longer necessary.

"Most national vitamin A programs supplement children twice a year, yet evidence suggests that more frequent supplementation could reduce mortality even further," they wrote.

"Research into alternative dosing approaches and delivery mechanisms, with proper evaluation, might enable programs to be more effective."

The active form of vitamin A is found in liver, whole milk and some fortified foods.

The review was funded by the World Health Organization's Department of Nutrition for Health and Development.