As a coin has two sides so does vitamin D, it is good in cancer but excess is harmful to the kidneys and liver. If taken in high doses vitamin D can be harmful to kidney and liver.
The study is based on intakes from 63 studies.
The study was done by the University of California researchers led by professor Cedric Garland looked at the relationship between blood levels of Vitamin D and the cancer risk.
As proposed by them, taking high doses - 1,000 international units (IU) or 25 micrograms - of the vitamin daily could lower risk by 50 percent for colon cancer and by 30 percent for breast and ovarian cancer. But more than 2,000 IU - 50 micrograms - a day could lead to the body absorbing too much calcium, possibly damaging the liver and kidneys. The information was given by Prof. Garland.
Supported by the researchers was the idea that the most effective way of getting this vitamin was through diet and supplements.
The source of the vitamin for us humans is the natural form of the D3 vitamin from exposure to sunlight as well as certain foods such as oily fish, margarine and meat.