Childhood Vitamin A Deficiency Linked to More Illness

Not getting enough vitamin A may put children at risk of gastrointestinal and respiratory disease, according to a new study.

The latest research involved nearly 2,800 children between the ages of 5 and 12 living in Bogota, Colombia. The study revealed that children were more likely to get diarrhea with vomiting and cough with fever the less vitamin A they had in their blood.

"Studies of older children have included a range of micronutrients administered together, but no study had estimated the potential role of vitamin A alone in this age group," senior author Dr. Eduardo Villamor, associate professor of epidemiology at the University of Michigan School of Public Health, said in a news release.

After measuring markers of other micronutrients including zinc, iron, folate and vitamin B12, researchers found that only vitamin A was related to illness.

"The association we found with vitamin A followed a dose-response pattern, in that higher blood concentrations of retinol were related to fewer symptoms," Villamor said.

The findings revealed that children experienced 18 percent fewer days with diarrhea and vomiting, 10 percent fewer days of cough and fever and 6 percent fewer visits to the doctor for every 10 micrograms per deciliter of retinol present in the blood.

Researchers said the next step is to determine if vitamin A supplements can lower the risk or severity of infection in older children.

"As we have learned from vitamin A supplementation to younger children, which has shown mixed success in preventing illness, the picture is more complicated than it might appear," Villamor said.

"The effects of micronutrients, including retinol, could vary in different settings due to the underlying nutritional status of the population, the epidemiologic patterns of the microorganisms that cause illness-whether viral, bacterial or parasitic-the age and possibly sex of children, and other factors. It's definitely uncertain whether supplementation is a one-fits-all solution," he added.

The findings are published in the Journal of Nutrition.