Systematic Review on 25-Hydroxyvitamin D Levels in Various Populations of the Russian North

We analyzed published data on the levels of serum 25(OH)D in apparently healthy individuals from the Russian Far North. The total sample included 2061 subjects of various age and ethnic groups. The serum levels of 25(OH)D and its age dynamics in the northerners living in towns are similar to those of the inhabitants of the temperate climate zone of Russia. Data on the age-related changes in the vitamin D status of the indigenous Arctic people with the traditional lifestyle are scanty. Serum 25(OH)D concentrations in the indigenous and alien population of the high-latitude regions reflect the seasonal changes in the daylight duration. The level of vitamin D decreases in winter and reaches minimum in February, i.e., after the end of the polar night. We compared data on rural Russian and indigenous people and found ethnic differences in the 25(OH)D concentrations; however, the vitamin D status of various indigenous groups of the Russian North is poorly studied. We could not find publications that analyze the 25(OH)D concentrations along with the direct assessment of food consumption. The available data do not contradict the opinion that the traditional food products are beneficial. However, there are no studies to support this opinion. There are little data on the effect of foods from marine mammal catch, marine and freshwater fishery, and venison on the vitamin D status of the indigenous people of the Russian North.