Vitamins May Make Kids More Allergy Prone

Highest risk seems to be among formula-fed infants

Many parents think that making sure their kids get lots of vitamins means they will grow up big and strong.

But this also may mean they'll grow up wheezing from asthma and allergies, according to recent research.

The study found that giving multivitamins to toddlers -- and more than half of them in America get multivitamins -- may increase the child's risk of developing asthma and allergies.

But parents should not rush to throw away those colorful chewables and should always follow their doctor's advice, said study author Dr. Joshua D. Milner, a clinical fellow at the National Institute of Allergy and Infectious Diseases at the National Institutes of Health.

Milner and his colleagues evaluated more than 8,000 children for their study. By 3 years of age, 10 percent of them had been diagnosed with asthma and about 5 percent had been diagnosed with food allergies.

Children who were fed formula and took vitamins before they were 6 months old were at "about a 70 percent increased risk" for a food allergy, compared with those who were formula-fed but not given multivitamins, Milner said.

Black infants -- formula-fed or not -- had about a 30 percent increased risk for asthma at age 3 if they took multivitamins before they were 6 months old, Milner said. The researchers had no idea why the asthma risk was so much higher for black children.

"Caucasian children had no increased risk for asthma, and breast-fed infants -- breast-fed at all -- did not have an increased risk for food allergies," Milner told HealthDay .

Researchers said that formula-fed infants may be more at risk for food allergies when they also take a multivitamin because of the higher amount of vitamin D in formula.

"Certain vitamins have direct effects on the immune system and can push it in certain directions," Milner said. "Vitamins A and D can push the immune system in allergic directions; vitamins E and C have been shown in test tubes to push you away from the allergic direction. This doesn't mean if you take vitamin D you will get an allergy."

There is no official recommendation from the American Academy of Pediatrics on giving children multivitamins, Milner said. However, the academy does recommend that healthy infants during the first two months of life -- along with children and adolescents -- should receive 200 international units of vitamin D a day to prevent rickets, a skeletal deformity linked to not getting enough of the vitamin.

But an expert had mixed feelings about the study.

"It is a fascinating study, although it has, I am afraid, the potential for a lot more concern than it warrants," Dr. Dennis Ownby, section chief of Allergy and Immunology in the Department of Pediatrics at the Medical College of Georgia in Augusta , told HealthDay .

"For those who need supplements, the risk of rickets is real and is, in my opinion, a far worse problem than asthma," Ownby said.