Paper of the Month: Vitamin D in serum is influenced by diet and season in North Greenland

Strong evidence links vitamin D status in man to skeletal health and muscle strength, and epidemiological data have further associated vitamin D deficiency with a number of inflammatory, infectious, cardiovascular and metabolic disorders, and with cancers. Vitamin D status is assessed by serum 25-hydroxy vitamin D (25OHD) that has dietary and dermal sources. Dermal 25OHD production depends on exposure to sunlight and varies with latitude and season. The seasonal difference in sunlight increases with latitude. This emphasises the importance of sun exposure during summer to compensate for the long Arctic winter night. However, sun exposure during summer is limited by the high solar zenith angle that decreases the intensity of the UVB radiation as it is absorbed by the oblique passage through the atmosphere. Dermal sun exposure is also limited by the use of protective clothing suggested by the low ambient temperatures in the Arctic. In addition, changes in ozone in the atmosphere may influence the UVB radiation. So, what is the vitamin D status in the Polar populations? Greenland hosts the most northern habitats on Earth and our study was conducted in the Disco Bay area in North Greenland (70o north). It included 97 Inuit (Eskimos) and non-Inuit (Caucasians) living 400 and 500 kilometres north of the Arctic Circle with over one month of both polar night and one month of midnight sun. Participants were surveyed at equinox, by the end of the polar night and after one month of midn...
Source: The Nutrition Society - Category: Nutrition Authors: Source Type: news