A recent study brings bad tidings for those heavy-handed on multivitamins. The research conducted by America's prestigious National Cancer Institute, reveals that those who take more than seven multivitamin tablets a week, can in fact increase their risk of contracting the most serious type of prostate cancer.

The researchers who published their work in Journal of the National Cancer Institute, followed 295,344 men who reported taking multivitamins more than seven times a week. It was seen that these men had a slightly greater risk of advanced or fatal prostate tumors.

If the doctors were to follow 10,000 men for 10 years, there would be about 30 extra cases of advanced prostate cancer and seven or eight extra cases of fatal prostate cancer associated with heavy supplement use, lead author Michael Leitzmann , postulated in the article.

While studies show that 35 percent of Americans take vitamins, Leitzmann says only 9 percent of men in his study took multivitamins more than once a day.

The authors found no increase in the risk of early prostate tumors among heavy vitamin users. The researchers speculate that perhaps high-dose vitamins had little effect until a tumor appeared, and then could spur its growth. They also found no heightened risk among men who took only one vitamin a day, Leitzmann says.

The authors stress that the study was not designed to prove that vitamins affect cancer risk. Yet he stresses, study results show that vitamin users should be cautious about taking more than the recommended daily allowance.

Victoria Stevens of the American Cancer Society says the report confirms her 2005 study on vitamins and prostate cancer. A February study in the Journal of the American Medical Association found vitamins A and E and beta-carotene pills have no health benefits and may increase the risk of death. "There certainly is no evidence in healthy, relatively well-nourished people that vitamins or anti-oxidants protect against chronic diseases," Stevens opines.

In the study, it was also observed that men who used a zinc supplement in addition to heavy multivitamin use were at significantly elevated risk of fatal prostate cancer. This "could be due to nonessential, potentially harmful trace elements contained in zinc supplements, such as cadmium, a known carcinogen," the researchers opine.