title: Vitamin D deficiency among northern Native Peoples: a real or apparent problem?
abstract: Vitamin D deficiency seems to be common among northern Native peoples, notably Inuit and Amerindians. It has usually been attributed to: (1) higher latitudes that prevent vitamin D synthesis most of the year; (2) darker skin that blocks solar UVB; and (3) fewer dietary sources of vitamin D. Although vitamin D levels are clearly lower among northern Natives, it is less clear that these lower levels indicate a deficiency. The above factors predate European contact, yet pre-Columbian skeletons show few signs of rickets-the most visible sign of vitamin D deficiency. Furthermore, because northern Natives have long inhabited high latitudes, natural selection should have progressively reduced their vitamin D requirements. There is in fact evidence that the Inuit have compensated for decreased production of vitamin D through increased conversion to its most active form and through receptors that bind more effectively. Thus, when diagnosing vitamin D deficiency in these populations, we should not use norms that were originally developed for European-descended populations who produce this vitamin more easily and have adapted accordingly.
authors.affiliation: Department of Anthropology, Laval University, Quebec, QC G1K 7P4, Canada. peter_frost61z@globetrotter.net
authors.forename: Peter
authors.initials: P
authors.lastname: Frost
mesh_terms: D000222:Adaptation, Physiological; D002170:Canada / Q000453:epidemiology; D006801:Humans; D007198:Indians, North American; D004930:Inuit; D014807:Vitamin D / Q000097:blood / Q000633:toxicity; D014808:Vitamin D Deficiency / Q000208:ethnology*
chemical_list: D014807:Vitamin D