Is There a Cancer Risk When Supplemeting with Vitamin C?

Many people have by now read somewhere in the media that vitamin C causes cancer. The question then posed is, should I avoid taking it?

Most likely, you're probably referring to recent findings that, in a test tube, vitamin C may act as a catalyst in making a toxin that damages DNA. That's a far cry from saying that supplementing with vitamin C causes cancer.

At fitFLEX, we believe that all studies must be looked at in the context of the body of research and soberly evaluated in a balanced way. This is in stark contrast to other news media, which reduce every piece of research to eye-catching hyperbole. We've grown accustomed to dubious claims, such as "bacon kills," "eat all you want and lose weight," and to contradictory claims, such as "coffee causes cancer" versus "coffee prevents cancer." The bottom line is that none of these outrageous statements about foods or supplements are true as reported by the media. To get at the truth, you need to look at the studies themselves.

Researchers present findings in which they generally shy away from extrapolating to extremes. In fact, if anything, the conclusions of most studies are more notable for their lack of definitive statements about what was studied than for their finality. A statement such as "further studies are needed" backs almost all conclusions; that's a far cry from what you hear or read in the mainstream media.

Back to your question on vitamin C. Although that study is certainly interesting, the bulk of evidence indicates that supplementing with vitamin C can provide many advantages to bodybuilders. Vitamin C is an antioxidant that helps boost the immune system and aids in recovering from the stress of training. Our position is that you can safely supplement with 500 to 3,000 milligrams (mg) per day (individual doses should not exceed 1,500 mg). If you're concerned about the safety of vitamin C supplements, be aware that only one study out of thousands has found a very small probability of vitamin C leading to biochemical reactions that could potentially result in tumor formation.