Vitamin D deficiency is an astoundingly common problem. A study from the Journal of the American College of Cardiology indicates that most of the general population simply doesn't get enough of it and according to the study, low vitamin D levels can greatly affect cardiovascular health. This deficiency also plays into increasing insulin resistance associated with diabetes as well as high blood pressure and increased inflammation.

Because it's only naturally available in a few foods (vitamin D fortified dairy products, beef liver, egg yolks and some fish), supplementation and getting sunlight is the only way to get it.

Vitamin D is responsible for regulating the absorption of calcium and phosphorus and most importantly, for facilitating normal immune system function. Having sufficient levels of vitamin D reduces your risk of infectious diseases by strengthening your immune system, which means that the vitamin D turns on key substances in your immune system which in turn triggers a strong response, allowing you to quickly fight off invaders before they can develop into a full-blown infection.

Most importantly, in a recent study Vitamin D3 seems to be more helpful than D2 in sustaining adequate levels.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.