According to a demographic study,
over 70% of Americans have insufficient blood levels of Vitamin D*.
Vitamin D3, popularly known as the "sunshine vitamin", is essential for strong bones and teeth. Why is it so important? Because it maintains your calcium balance, aids cellular differentiation in the body, boosts the immune system, play a role in the secretion of insulin, and regulates blood pressure.
Unfortunately, the active form Vitamin D3 does not naturally occur in foods so that getting enough of it can be a challenge. How to boost your levels?
Take a daily supplement. While vitamin D comes in two forms, vitamin D2 and vitamin D3, vitamin D3 is the most effective for maintaining adequate levels of vitamin D in the body. The recommended daily vitamin D dosage is 400IU. So be sure that the Vitamin D supplements you are taking contains at least this much Vitamin D3.
Eat foods rich in vitamin D. Very few foods in nature contain Vitamin D. These include fish (specifically salmon, mackerel, sardines, and oysters), vitamin D-fortified cereal and orange juice, spinach, tofu, and dairy products such as vitamin D-fortified milk, cream, and cheese.
Soak up some rays. Try to spend about 5 to 15 minutes in the sun without sunscreen, three times each week, being careful to avoid overexposure. Of course, this might not be practical in cold weather, in which case you should turn to foods and supplements.
* Demographic Differences and Trends of Vitamin D Insufficiency in the US Population, 1988-2004. Adit A. Ginde, MD, MPH; Mark C. Liu, MD; Carlos A. Camargo Jr, MD, DrPH Arch Intern Med. 2009;169(6):626-632.