The US Preventive Services Task Force finds little evidence supporting the use of vitamin supplements to reduce the risk of heart disease or cancer.

Having reviewed many studies, the US Preventive Services Task Force concludes that vitamins A, C and E, folic acid, multivitamins, or antioxidants do not seem to protect health. There is no huge impact on the risk of heart disease and cancer. And smokers who take beta-carotene may even be endangering their health, at least according to some studies.

However, the Task Force acknowledges that there may be some merit in long-term vitamin use - as the studies reviewed were limited in this respect. Where vitamins seemed to confer some benefit, it was hard to know whether had more to do with participants who took supplements having a healthier lifestyle. The take-home message is that if you want to avoid heart disease and cancer, it's best to concentrate on a good diet with lots of vitamin and anti-oxidant rich produce.

Source

Annals of Internal Medicine 1st July 2003