FRIDAY, Jan. 13, 2006 (HealthDay News) -- For years, health workers have distributed iron and folic acid supplements to malnourished children throughout the developing world, to help fight pediatric anemia.
But two studies released this week cast doubt on the wisdom of these interventions.
One of the studies, conducted in malaria-plagued East Africa, found that children who took the supplements were more like to be hospitalized or die from the mosquito-borne disease than those who didn't.
The other research was done in Nepal. That study found that taking iron or folic acid supplements had no effect, positive or negative, on a child's risk of death.
Both studies were published in the Jan. 14 issue of The Lancet, and were led by researchers at the Johns Hopkins University Bloomberg School of Public Health.
"It has generally been believed and recognized that these supplements, given in areas of the world where there is a high incidence of anemia, have benefits," said Dr. Robert E. Black, chairman of the school's department of international health. "But there has been concern about their effects in areas with a high incidence of malaria."
The study he directed was designed to address that issue. It included more than 24,000 children aged 1 to 35 months living in a region of Zanzibar, where malaria is endemic. A third of the children received folic acid and iron supplements, another third received iron, folic acid and zinc supplements, while the final third received no supplements.
The iron-plus-folic acid segment of the trial was ended prematurely because children who got those supplements, with or without zinc, had a 12 percent higher risk for hospitalization for severe disease or death than those who got no supplements.
An accompanying editorial by staff members of the Kenya Medical Research Institute gave a possible explanation for the adverse effects in the Zanzibar trial. Some studies have shown that when drugs are given to treat malaria, the presence of iron and folic acid slows the process by which the body rids itself of the malaria parasite, they wrote.
The other study, done in a malaria-free part of Nepal with more than 25,000 children, was also stopped early when researchers noted no difference in the death rate for children who got the supplements vs. those who didn't.
The World Health Organization, which helped fund the studies, now has to reconsider its recommendations, Black said.
"In areas such as Nepal, there is a question of risk and benefit," he said. "At this point there doesn't appear to be a risk," but neither did there appear to be any immediate apparent benefit, he said.
However, Black added that "there might be benefits [from supplementation] primarily to the cognitive development of children. Studies have been equivocal, but some show benefits."
In regions where malaria is a problem, the key factor may be singling out children who might benefit from the supplements, he said. "If they have an iron deficiency, the supplements will have a benefit," Black said.
The problem is that a test would be needed to select children to be given the supplements, "and at this point we don't have a good, inexpensive measure that can be used," he said.
For more on anemia, head to the National Library of Medicine.