Correlates of vitamin D insufficiency in an affluent adult population

Objectives: Vitamin D is necessary for bone health and calcium metabolism. Vitamin D deficiency may play a role in coronary artery disease, some cancers, autoimmune disease, and glucose tolerance. Vitamin D deficiency may be prevalent even among affluent US adults. Methods: We conducted a retrospective chart review study of 287 adult patients who underwent executive physical examinations between April 2009 and May 2010 in Chicago, Illinois. Data collected included age, sex, body mass index, vitamin D levels, supplement use, fish consumption, milk consumption, hours spent outdoors, and sunscreen use. Vitamin D insufficiency was defined as <30 ng/mL. Results: The mean vitamin D level was 40.0 ng/mL (standard deviation 16.6), which varied by month. The mean vitamin D level ranged from 32.9 ng/mL in January to 55.4 ng/mL in September. Insufficient levels of vitamin D were observed in 30.3% of patients. Younger age (younger than 40 years); no milk or fish consumption; no use of multivitamins, vitamin D supplements, or calcium supplements; no sun exposure; and routine use of sunscreens were positively associated with vitamin D insufficiency. Conclusion: Vitamin D insufficiency in almost one-third of patients presenting for executive physicals may be indicative of a widespread nutritional deficiency in the US population.