Vitamin supplements do not protect against lung cancer, according to a study of more than 77,000 vitamin users. In fact, some supplements may even increase the risk of developing it.

“Our study of supplemental multivitamins, vitamin C, vitamin E and folate did not show any evidence for a decreased risk of lung cancer,” wrote the study’s author, Christopher G. Slatore, M.D., of the University of Washington, in Seattle. “Indeed, increasing intake of supplemental vitamin E was associated with a slightly increased risk of lung cancer.”

The findings were published in the first issue for March of the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine.