Do iron supplements worsen the course of malaria? Researchers aren't sure, and the uncertainty has jeopardized efforts to treat the debilitating effects of iron deficiency in parts of the world where malaria and other infectious diseases are common.

The National Institutes of Health (NIH) has received a grant from the Bill and Melinda Gates Foundation to establish a research programme to find the best ways to diagnose and treat iron deficiency and better understand its interaction with malaria and infectious diseases in parts of the world where such diseases are common. The Gates Foundation grant is $9.3 million over a five-year period, a NIH press release said.

In the past, public health officials have treated iron deficiency in these areas by distributing iron supplements to local populations. Although a few people who had received the supplements were not iron deficient, it was assumed that the extra iron would not do them any harm.

Recently, a few studies have indicated that extra iron may in fact place individuals who are not iron deficient at greater risk for death from malaria or another infectious disease, and at greater risk for hospitalization from the complications of malaria. Consequently, public health officials have become hesitant to continue giving iron supplements to entire populations in parts of the world where malaria rates are high, depriving large numbers of iron-deficient people of the health benefits of iron supplementation.

"Previously, public health officials would provide iron supplements to entire populations, assuming that they would do no harm to those few individuals who didn't require them," said Dr. Elias A. Zerhouni, M.D., director of the National Institutes of Health. "The purpose of this project is to find ways to identify those people who need iron supplements and the most efficient ways to provide it to them."

"To improve global health, effective health interventions are critical," said Ellen Piwoz, Sc.D., M.H.S., senior program officer at the Gates Foundation. "By addressing important unanswered questions about the relationship between iron supplements and malaria, this research will help guide public health practice in developing countries."

Iron deficiency can result from insufficient iron in the diet or from blood loss, explained the project officer for the initiative, Daniel J. Raiten, Ph.D., a health scientist administrator at NIH's National Institute of Child Health and Human Development. Among its roles in the body, iron is an essential component of red blood cells. Iron deficiency can progress to anaemia, the shortage of red blood cells. As a result, people with iron deficiency may feel weak and fatigued.

"Iron deficiency is a tremendous economic and social problem," Dr. Raiten said. "The fatigue and weakness hinder adults' ability to work and function, and the neurological complications of iron deficiency can have a negative impact on children's ability to learn."

Although iron is found in vegetables, fruits, grain, and legumes, iron in plant-based foods is not absorbed as readily by the body as iron from red meat, liver, and egg yolks. As a result, vegetarians and other people who consume little or no red meat or eggs are at risk for iron deficiency. Women who have heavy menstrual periods, as well as pregnant women who must supply blood to meet the needs of the foetus are also at high risk for iron deficiency.

Dr. Raiten said that by some estimates, there are two billion people worldwide who may be anaemic, and about half of those cases are due to iron deficiency.

Iron deficiency commonly occurs in parts of the world where malaria and other major infectious diseases are also common, Dr. Raiten said. Malaria, caused by a parasite transmitted through the bite of an infected mosquito, can result in severe headache, high fever, chills, and vomiting, and can be fatal. The World Health Organization estimates that 300 million cases of malaria occur around the world each year. More than a million of these result in death, most often among children.

Dr. Raiten explained that the objectives of this project are: to test the safety and effectiveness of various methods and strategies for preventing or treating iron deficiency; to identify screening tests and other measures to gauge how much iron a person has (for example, levels of iron in the blood) and how it's being used by the body; to understand the biological processes by which iron might affect a person's response to malaria or other infections; to translate information gained from these studies into practical means for providing sources of iron to communities with a high proportion of iron-deficient people. This transfer of information will be accomplished through a partnership with the World Health Organization.

To begin this work, the project will constitute a technical working group to review the current evidence and identify the most significant research questions to be pursued.