Early Vitamin Use Linked to Allergy, Asthma
But Infant Study Is Far From Conclusive
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.
Vitamin use at age 3 was also linked to an increased risk for food allergies, but not asthma, in all children, regardless of whether they were breast- or bottle-fed as infants.
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.