The effect of skin color variation on 25(OH)D concentration in Polish children

Abstract

AbstractObjectivesSkin color is a classic example of a visible human trait that varies widely among and between human populations; it has evolved finely balancing photoprotection and 25(OH)D (vitamin D) synthesis as opposing selection forces. While the health effects of vitamin D deficiency in Northern European populations are profound, we are yet to accurately characterize the evolutionary relationship between vitamin D requirements and skin color diversity.Materials and MethodsThis study explored this relation among a cohort of 170 children from central Poland considering season of measurement and socioeconomic status (SES). Alongside completed questionnaires, saliva was collected and the level of 25(OH)D was assessed using an enzyme‐linked immunosorbent assay kit; furthermore, a Dermaspectrometer was used to measure skin color by recording the Melanin Index (MI).ResultsFirst, 25(OH)D concentration or skin color variation are not significantly different between boys and girls; second, 25(OH)D concentration is lower in late autumn than in spring, while skin color (MI) is darker in autumn; crucially, we found significant association between MI and 25(OH)D concentration: higher MI is significantly associated with lower 25(OH)D levels only in boys measured in autumn, and not in spring.ConclusionsThese results shed light on the factors affecting 25(OH)D concentration and MI variation in a cohort of Polish children: they offer an evolutionary perspective on the potential role of vitamin D as a driver of skin color diversity while informing a key public health debate.