Vitamin D supplementation is an area of ongoing research for the prevention of food allergies. Vitamin D is integral to the proper functioning of the immune system, and vitamin D insufficiency and limited sun exposure are associated with the development of food allergies in observational research.[1][2][3][4] However, whether vitamin D supplementation actually decreases the incidence of food allergies is not clear.[5]
Currently, there is also no evidence to support the use of supplements in treating tree nut allergies. However, there is ongoing research investigating the effects of certain Chinese herbs on the immune system, including their potential to dampen the inappropriate immunologic response to food proteins.[6] Of these herbs, berberine appears to be the most powerful suppressor of IgE production.[7] More research is needed to determine whether these supplements could decrease allergic reactions.