Vitamin C helps preserve vitamin E in smokers

Vitamin C supplements can help reduce the high rate of vitamin E depletion that occurs in smokers, according to the findings of a small study published in the journal Free Radical Biology and Medicine.

As senior investigator Dr. Maret G. Traber told Reuters Health, "if you are under oxidative stress, have low vitamin C intakes, then vitamin E doesn't do its job as well as it should and gets destroyed."

Vitamin C supplements appear to reduce this tendency in smokers, Traber of Oregon State University, Corvallis and colleagues report, based on the findings of a study with 11 smokers and 13 nonsmokers.

"We studied college-age people who smoked a half a pack to a pack of cigarettes per day," she said. The subjects were randomly assigned to receive vitamin C supplements at 500 mg twice daily for 2 weeks or placebo.

After 2 weeks, the study participants switched over to the other treatment. In both phases of the study, the subjects did not know if they were receiving a supplement or placebo.

The researchers found that during the placebo phase, tocopherols, the active form of vitamin E, disappeared significantly faster in smokers than in non-smokers. The disappearance rates of blood levels of alpha-tocopherol in smokers were inversely correlated with blood levels of vitamin C.

Vitamin C supplements in both groups slowed the disappearance rate of alpha-tocopherol by 25 percent and blood levels of gamma-tocopherol by 45 percent.

"Vitamin E and vitamin C have been predicted to interact based on more than 50 years of test tube studies," Traber continued. "This is the first demonstration that vitamin E reacts with vitamin C in the human body."

SOURCE: Free Radical Biology and Medicine, February 15, 2006.