To validate a sun exposure questionnaire against objective measures of change in skin color and to assess its validity in predicting 25(OH)D in a sample of African Americans and Hispanics with type 2 diabetes. Ninety subjects were enrolled. The sun exposure score was calculated by multiplying the time spent outdoors times the skin exposed score. Skin color was determined by reflectance colorimetry. The relationship between serum 25(OH)D, skin exposure score and stomach skin color was evaluated by a multi-linear regression model. The unadjusted model showed that skin exposure score (P = 0.037), and stomach skin color (P = 0.021) were associated with serum 25(OH)D. This relationship remained significant only for stomach skin color (P = 0.020) after controlling for covariates. It may be possible that the color of the skin is a better predictor of 25(OH)D in this particular population than sun exposure behaviors.
Keywords: Skin color; Sun exposure; Type 2 diabetes; Vitamin D.