Contrary to popular belief, even on a completely bluebird day in January atop the highest lift in Vail, you’re not getting vitamin D from the sun. Vail, or any other ski hill in North America for that matter, is too far above the equator to receive the type of direct sunlight needed to create vitamin D during the winter months. Which is a bummer because this recently popular “sunshine vitamin” plays a key role in boosting the immune system. In particular, it triggers and arms the body's T cells, the cells in the body that seek out and destroy any invading bacteria and viruses. Last year, scientists at the University of Copenhagen discovered that Vitamin D is crucial to activating our immune defenses, and that without sufficient intake of the vitamin, the killer cells of the immune system will not be able to react to and fight off serious infections in the body. Vitamin D can be obtained through the diet, though very few foods naturally contain it. The foods that do include fatty fish, fish liver oil, and eggs. Smaller amounts are found in meat and cheese. A person’s vitamin D status is determined by measuring the level of 25-hydroxyvitamin D in blood serum.  Current lab ranges are 30-80 ng/mL, though most functional healthcare practitioners recommend levels be at least 50 ng/mL - even higher in some cases. Though the RDA for vitamin D is 600 IU/day of vitamin D, most health experts are suggesting closer to 5,000 IU/day for optimal immune function.

So to up your chances of not getting sidelined by a cold or flu this ski season, be sure to follow these three guidelines. That way you can spend your “sick days” skiing.