New developments in medical research continue to show that no one should be deficient in Vitamin D levels in their blood. Vitamin D is a key factor in boosting the immune system, building and maintaining strong bones, and fighting off some cancers. It is now also apparent that Vitamin D is crucial to maintaining good cardiovascular health.

Recent research indicates that elevated levels of Vitamin D play a strong role in preventing heart attacks. Vitamin D improves resistance to infection, which eliminates chronic inflammation which
often leads to heart attacks. There is also evidence that Vitamin D improves the absorption of
calcium in the bones, which leaves less calcium in the bloodstream to aggravate hardening of the arteries.

A recent article in "Science News" reports on a ten year study of 18000 male physicians that showed that low Vitamin D levels double the risk of heart attack. This makes lack of Vitamin D a heart disease risk factor on par with smoking and high blood pressure.

For a long time the standard recommendation has been a daily allowance of 400 international units of vitamin D per day, but new information strongly suggests that most people should get up to 2000 units per day. Doses up to 10000 units per day are not likely to cause any toxic effects.

The sun is an important source of vitamin D. When ultraviolet radiation hits the skin,Vitamin D is synthesized naturally in the body. But, don't throw out your sunscreen just yet. Unfortunately, ultraviolet radiation is also linked to the development of skin cancer. The best way to get adequate Vitamin D may be to allow yourself some unscreened sun exposure each day, but to use sunscreen at all other times, and to supplement your diet with Vitamin D supplements.

It is difficult to get adequate doses of vitamin D from food alone. The two best food sources are fatty fish and vitamin supplemented milk, but a typical glass of milk only contains 50 to 100 international units of vitamin D. A typical serving of salmon may contain 300 to 400 units, and a can of sardines has between 200 and 300 units.

To get a regular daily dose of vitamin D in the 1000 to 2000 international unit range, it
is probably easiest and most effective to add a daily supplement (the Vitamin D3 type are best) to normal good nutrition.