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

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

Allergen Avoidance Versus Tolerance Induction

Effective prevention, curative treatment, and accurate, rapid diagnosis of allergies are still major unmet needs according to the EAACI and EFA. As at least 60 million people are daily burdened by the consequences of their allergic disease(s), the need for more research is not only stressed by patient organizations, but also by health care professionals and the World Health Organization. Even though knowledge of the mechanisms underlying allergic responses is rapidly increasing, there are still a number of critical questions to be answered. In this chapter, a brief introduction on the use of biologicals, allergen-specific immunotherapy, and dietary compounds to actively reduce the allergic responses is provided with recommended literature for more detailed information about the individual topics. Furthermore, the current believes about the usefulness or risks of maternal allergen intake on the susceptibility of the infant are discussed. Finally, the debate on the suitability of partial or extensive hydrolyzates for specific target groups is summarized and is put into context with an opportunity to induce tolerance induction