In the summer Alaska is known as the land of the midnight sun, but in the winter Alaska becomes the land of no sun. During the winter months some areas of Alaska don’t see the sunrise for 40 days! In the metropolitan area of Anchorage though, some days can see as little as 4.5 hours of daylight. Less daylight means less sun and less sun exposure can lead to decreased levels of vitamin D. According to the Alaska div. of public health, “Vitamin D is an essential fat-soluble vitamin that is primarily responsible for maintaining normal serum concentrations of calcium and phosphate by increasing their absorption in the small intestine. Vitamin D deficiency is known to cause demineralization of bones and other tissues, leading to skeletal problems such as osteomalacia and rickets. “ They also say that 80%-90% of the Vitamin D in a human is synthesized within the skin after exposure to Ultraviolet B (UVB) light. There are two forms of Vitamin D supplements over the counter Vitamin D2 and Vitamin D3 (Ergocalciferol and cholecalciferol).
Vitamin D3 is more effective for deficiencies as it is easily converted and stored by the body and is more akin to the natural form. So how does someone who lives in 40 days of no sunlight not become vitamin deficient? In parts of rural Alaska where daylight is scarce local diets tend to be high in Salmon and marine mammal fats both of which are extremely rich in vitamin D. It is also thought that during the summer months Alaskans are exposed to the sun more frequently with some days seeing up to 21 hours of daylight. The overcompensation in daylight can lead to higher levels of vitamin D stored in the fat. This may be why some residents don’t notice a difference during the winter months. This event is not isolated to Alaska however,
Vitamin D deficiency is now recognized as an epidemic in the United States. Avoid being apart of it, get some sun eat some fish and take your vitamins!