Vitamin D is an incredibly important and useful vitamin that is both often overlooked and a common deficiency. You are at risk for a vitamin D deficiency if you meet any of the following criteria:

• Work indoors
• Wear sunscreen
• Are vegetarian/vegan
• Live above 40 deg. latitude
• It's winter where you live

Right now research is showing alarmingly high rates of vitamin d deficiency throughout the globe. Everywhere from Russia to Saharan Africa, people of every class and skin tone. Worse is that vitamin D deficiency doesn't manifest itself in symptoms until it's far too late, and its affects on your health are many.

Over time deficiency can lead to an increased risk of death from cardiovascular disease, bone deformations & weakness, and cancer. The only way to be certain you have adequate levels (blood levels in the 45-70ng/ml range) is to get your blood taken and tested.

Vitamin D gives a host of benefits when your body has proper levels. Its most notable function is to regulate the flow of calcium from your bones into your bloodstream. New research as of late has shown many other benefits as well. Runners have noted an increase in endurance levels after correcting a deficiency. Studies have suggested that it may reduce the risk of heart disease. It's also been shown that taking vitamin D supplements during the flu season boosts your immune system and may protect against getting infected.