Probability of vitamin D deficiency by body weight and race/ethnicity

Introduction: while most physicians recognize that vitamin d status varies by skin color because darker skin requires more light to synthesize vitamin d than lighter skin,the importance of body weight to vitamin d status is a newer,less recognized,finding. the purpose of this study was to use nationally representative us data to determine the probability of vitamin d deficiency by body weight and skin color. methods: using data for individuals age ≥6 years from the 2001 to 2010 cycles of the us national health and nutrition examination survey,we calculated the effect of skin color,body weight,and age on vitamin d status. we determined the probability of deficiency within the normal range of body weight for 3 race/ethnicity groups at 3 target levels of 25-hydroxyvitamin d. results: darker skin colors and heavier body weights are independently and significantly associated with poorer vitamin d status. we report graphically the probability of vitamin d deficiency by body weight and skin color at vitamin d targets of 20 and 30 ng/ml. conclusion: the effects of skin color and body weight on vitamin d status are large both statistically and clinically. knowledge of these effects may facilitate diagnosis of vitamin d deficiency.