Sun exposure, skin color and vitamin D status in Arab children and adults

Abstract

Accumulating evidence suggests an increased prevalence of vitamin D deficiency in the Middle East and North African countries. Sunlight has long been recognized as a major provider of vitamin D and lighter skin color has been associated with better vitamin D status. In this context, we aimed to determine whether 25-hydroxyvitamin D[25-(OH)D] concentrations are related to skin color, sun exposure and gender among healthy Saudi children and adults. A total of 808 Saudi children (age = 14.6 ± 0.04 years) and 561 (age = 31.4 ± 0.3 years) adults of both genders were included in this study. Levels of sun exposure and skin color were determined using a standard questionnaire. Anthropometry and plasma 25-(OH)D concentrations were analyzed. On the basis of duration of sun exposure (<20 min vs. >20 min), a significantly lower concentration of 25-(OH)D (40.9 ± 1.2 vs. 35.5 ± 1.8 nmol/l; p < 0.019) was demonstrated in dark-skinned boys with exposure time less than 20 min than those exposed longer than 20 min. We were unable to show an effect of sunlight exposure or skin color on vitamin D status of children or adults, except in dark-skinned boys who had lower 25(OH)D concentrations associated with limited sun exposure.