Experimental Biology 2010: Vitamin D Deficiency As A Risk Factor For Allergy In The Us Using The Nhanes Survey

Purpose of Study: Vitamin D has been reported in very high rates in US population and implicated in various diseases such as diabetes, high blood pressure, cardiovascular disease, many cancers and in immune system dysregulation. Our hypothesis is that low vitamin D has been implicated with increased incidence of various types of allergic conditions.

Methods Used: The National Health and Nutrition examination survey (NHANES) 2005-2006 as a cross sectional survey done on the non-institutionalized population of the United States by the Centre for Disease Control and Prevention and National Centre for Health Statistics consists of an extensive interview done at home and an examination done at a mobile center. An allergy questionnaire provided interview data on self-reported allergic diseases including hay fever, allergies and eczema .The data was collected using the question “Has the doctor or other health professional ever told that you have allergies and using the lab parameter vitamin D less than 10ng/ml. The data was analyzed by logistic regression with SAS version 9.1 (Cary, NC) using the PROC SURVEY methods.

Summary of Results: Out of 10348 people who participated in 2005-2006 NHANES survey, our final sample consisted of 4979 people after deleting people less than 20 years and those with missing values . The vitamin D deficiency was positively correlated with prevalence of allergies (odds ratio of 1.37, 95% CI of 1.14 to 1.69). After adjusting the model for age, gender, race, smoking, alcohol, and educational status odds ratio still remained significant (OR of 1.34, 95% CI of 1.10 to 1.63). A positive correlation was noted with rashes, sneezing and sinus infections.

Conclusions: Our study showed a positive association between vitamin D deficiency and prevalence of allergies. Based on the magnitude of deficiency and its association with other diseases a careful consideration has to be given in educating the general population about the vitamin D intake. 1,25(OH)(2)D(3) can potentiate the efficacy of allergen immunotherapy used for allergic rhinitis therapy effecting regulatory cytokines IL-10 and TGF beta. Supplementation can result in correction of defects in cathelicidins in the innate immune system of atopic subjects related to eczema.More research is needed to confirm this relationship and to elucidate its effects on the immune system.