For a long time we have known that vitamin D plays an important role in keeping bones strong. It is essential in combination with calcium to reduce the risk of osteoporosis and to speed the healing of bone fractures. For this reason, we supplement our milk with it, and the U.S. Food and Drug Administration recommends a daily dose of 400 international units. However, recent scientific studies strongly suggest additional roles for the vitamin in maintaining good health, and also suggest that the daily dose should be two to five times the current recommended minimum.
Long term studies of large numbers of people are beginning to show that lower intake of Vitamin D is associated with a higher risk of developing cancer. Scientists have observed a relationship between low blood levels and the occurrence of prostate cancer, and low levels are associated with a higher risk of developing colon cancer and other cancers of the digestive system. There may even be a link between the risk of certain autoimmune diseases and low levels of this vital nutrient.
Health Food Vitamin
Although for a long time the standard recommendation has been a daily allowance of 400 international units per day, new information strongly suggests that most people should get up to 2000 units per day. It is very unlikely that doses up to 10000 units per day will cause any toxic effects.
The sun is a potent source of vitamin D, and any time ultraviolet radiation hits the skin, it is synthesized naturally in the body. Unfortunately, ultraviolet radiation is also linked to the development of skin cancer, so perhaps we should keep using our sunscreen and look to other sources for our daily vitamin dose.
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. 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 in the 1000 to 2000 international unit range, it is probably easiest and most effective to add a daily supplement to normal good nutrition. Vitamin D supplements (the vitamin D3 type are best) are readily available at a reasonable price. Considering the evidence accumulating steadily that adequate doses provide substantial health benefits, this is one investment in daily supplements that may pay significant dividends in quality and quantity of life.