The association between use of vitamin supplements during the first six months of life and risk of developing asthma or food allergies during early childhood was assessed in a prospective cohort study of more than 8,000 children. After adjustment for potential confounding variables (including breastfeeding, smoker in the household, race, income, and prematurity), a history of vitamin use within the first six months of life was associated with a 27% increase in risk of asthma in black infants, and a 63% increase in risk of food allergies in exclusively formula-fed children.
Comment: The findings in this study are surprising, because several components of the average multiple vitamin formula (particularly vitamin C and vitamin B6) have been shown to be effective for preventing or treating asthma or allergies. Animal or in vitro studies also suggest that niacinamide and pantothenic acid might be protective. It is conceivable that early supplementation with vitamins causes deleterious changes in the immature immune system or intestinal tract, leading to an increased risk of asthma or allergies.
A more likely explanation for the associations observed in this study is that many pediatric vitamin preparations contain allergenic excipients. One of the leading brands of infant vitamin drops contains not only artificial flavor and color, but also polysorbate 80, a known cause of hypersensitivity reactions. Once infants graduate from liquid to chewable vitamins, it gets worse: the number of artificial yellows, reds, and blues with which they are bombarded in some of these preparations increases to a level that would make a bag of M&Ms blush. Some vitamin manufacturers, on the other hand, take great care to make their products hypoallergenic. Before we conclude that giving vitamins to babies is a bad idea, the results of the current study should be re-analyzed, considering the incidence of asthma and allergies as a function of the specific brands of vitamins used.
Milner JD, et al. Early infant multivitamin supplementation is associated with increased risk for food allergy and asthma. Pediatrics 2004;114:27-32.
