According to a study, made by researchers at the Moores Cancer Center in San Diego and published in the American Journal of Public Health, a large daily dose of vitamin D i.e. 1,000 international units (IU) (25 micrograms), could cut the risk of developing some common cancers by as much as 50 percent!
Analysis carried out during the study, showed that the "natural" form of vitamin D, specifically called vitamin D3, could substantially reduce a persons chances of developing common cancers, such as colon, breast and ovarian cancer.
Prof. Cedric Garland, from the University of California, who led the review study, concluded, "Primary prevention of these cancers has been largely neglected, but we now have proof that the incidence of colon, breast and ovarian cancer can be reduced dramatically by increasing the public's intake of vitamin D."
According to researchers, the main role of vitamin D, in the body is not only to maintain the balance between calcium and phosphorous in the blood, which helps keep bones strong, but also to regulate cell growth and determine what a cell becomes. This is why a deficiency of vitamin D may allow cells to become cancerous rather than becoming healthy cells.
Vitamin D3, commonly known as the 'sunshine vitamin', is normally produced in the skin by the body itself after exposure to sunlight, however, in the absence of adequate amount of sunshine, it may also be obtained from dietary sources, such as oily fish, eggs, salmon and meat.
The study also found that survival rates for darker-skinned people with breast, colon, prostate and ovarian cancers were worse than for white people. This they argue is because the high melatonin content in darker skin which reduces its ability to produce vitamin D. The obese too, had lower survival rates, possibly because they have trouble metabolizing vitamin D through their fatty tissues.
However, researchers warn that too a high dose of vitamin D may come with its own set of risks.
According to Sara Hiom, head of health information at Cancer Research UK, " More than 2,000 IU a day can make the body absorb too much calcium, and damage the liver and kidneys. There is evidence to suggest that the vitamin plays a role in keeping cells healthy. But further research is needed to understand what role vitamin D may play in preventing cancer in humans."