July 6, 2004 -- New research suggests that formula-fed infants that take a multivitamin are more likely to develop food allergies and asthma. While the findings need to be confirmed, researchers say they could help explain a steep rise in childhood allergies and asthma in the U.S.
More than 8,000 breastfed and formula-fed infants were followed from birth to age 3 to assess the impact of early vitamin supplementation. Laboratory and animal studies suggest that certain vitamins play a role in the development of allergies and asthma.
The American Academy of Pediatrics recommends vitamin supplementation for breastfed infants to ensure that they get adequate amounts of vitamin D, but there are no such recommendations for formula-fed infants and children. Even so, lead researcher Joshua Milner, MD, says more than half of the young children in the U.S. take multivitamins.
"We found that a large number of formula-fed babies were also given multivitamin supplements when there was no recommendation to do so," Milner tells WebMD. "The thinking is probably that it won't hurt and might help. This study does not prove that it does hurt, but we certainly need to study this further."
Race Plays a Role
The investigation, reported in the July issue of the journal Pediatrics, involved data from a government study that followed a group of mothers and infants from 1998 until 1991. Researchers controlled for factors known to be associated with asthma and food allergy risk.
Roughly 10% of the participants developed signs of asthma and 5% had been diagnosed with food allergies by age 3. A history of vitamin use within the first six months of life was associated with a 27% increase in asthma risk among African-American children but not white children. Among children who were never breastfed, early vitamin use was associated with a 63% increase in food allergy risk regardless of race.
Although it is just a theory, Milner says the fact that African-American children are more prone to vitamin D deficiencies may help explain the racial difference seen in the study. People with lighter skin more easily produce vitamin D from sun exposure, and some studies indicate that the vitamin plays a key role in immune system function. Allergies, and asthma that stems from allergies, are due to an overreaction of the immune system to an allergy trigger.
Ask Your Child's Pediatrician
Pediatric allergist Dennis Ownby, MD, calls the new research "intriguing" but says the findings are far from conclusive, especially with regard to the asthma findings because asthma is often not diagnosed until after age 3. Ownby is a professor of pediatrics and medicine at the Medical College of Georgia in Augusta.
But he adds that the study does raise interesting questions about the safety of supplementing normal infant diets with multivitamins.
"I am afraid that the message that has been conveyed to parents is that their child will be healthier if they take multivitamins, and that if one vitamin is good, two might be better," he tells WebMD. "Parents need to ask their child's physician about vitamin use and give only the recommended dosage. A standard supplement is probably adequate for most breastfed babies, and formula-fed babies probably don't need additional vitamins."