Findings from a 10-year study indicated that intake of nutrient in large quantity can increase risk of some diseases rather than reducing them. This study revealed that men who took folic acid supplements were at more than twice risk of prostate cancer as compared to those who didn't take the supplements. However men who got adequate amounts of folate in their diet were at slightly lower risk. Folic acid is a synthetic version of folate, a basic nutrient found in green, leafy vegetables.

Researchers followed 643 men for a decade. Data analysis revealed that prostate cancer risk was 9.7 percent for the men on the daily 1-milligram supplements, and 3.3 percent for men on placebo.

Study leader Jan Figueiredo, an assistant professor of preventive medicine at the University of Southern California said: "Folate plays an important role in cell growth and division, and cancer cells often uprate their folate receptors. Folic acid, the synthetic version, has more bioavailability, meaning that the effective dose in the cell is higher than what you get from natural sources."

Figueiredo added: "Since we fortified, the amount of folate we consume from fortified foods is probably more than sufficient,"