Vitamin D deficiency among northern Native Peoples: a real or apparent problem?

• Published in: International Journal of Circumpolar Health
• Main Author: Frost, Peter
• Format: Text
• Language: English
• Published: Co-Action Publishing 2012
• Subjects: Circumpolar Voices; inuit
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3417586; http://www.ncbi.nlm.nih.gov/pubmed/22456053; https://doi.org/10.3402/IJCH.v71i0.18001

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.1