Carotenoids are antioxidant compounds found in plants and are responsible for the bright colors of fruits and vegetables. Some, but not all, carotenoids can be converted by the body into vitamin A.
There is evidence that carotenoids may play a role in allergic conditions. A cross-sectional study published in Public Health Nutrition (2006;9(4):472–479) examined blood carotenoid levels in 547 adults and their relationship to symptoms of allergic rhinitis (hay fever).
The researchers found an inverse relationship between circulating carotenoid levels and the presence of allergic rhinitis—individuals with higher carotenoid levels were less likely to report symptoms. Blood levels of vitamin C and vitamin E were also measured, but neither showed a similar relationship with allergic rhinitis.
These findings suggest that carotenoids may have effects on allergic symptoms that are distinct from other antioxidant vitamins.
