Research led by Theodore Braske at Ohio State University found that men taking high doses of Vitamin B6 and B12 supplements over a ten-year period face a significantly increased risk of developing lung cancer. The risk was found to double in men generally and triple or quadruple in men who smoke, while no such risk was observed in women. The study warns against "super-physiological" doses found in some supplements and energy drinks, which can exceed 8,000% of the recommended daily allowance.
