Vitamins are commonly associated with health benefits, but research continues to suggest that men who take vitamin B6 and B12 in high doses are at higher risk of developing lung cancer.
What the research says
A study published in 2017 found that using vitamin B6 and B12 individual supplements was associated with a 30 percent to 40 percent increase in lung cancer risk among men. There was no notable risk for multivitamin usage. Men who take the vitamins and smoke showed an even higher risk of lung cancer. There was no increased risk for women, the study noted.
A study published in 2021 backed up the findings, although it solely looked at dietary vitamin B12 levels.
Marshfield Clinic Health System oncologist/hematologist Dr. Dean Delmastro says the issue is with men taking very high doses of these particular B vitamins. Levels are much higher than you would find in an average multivitamin.
How are they linked?
Why this link between B vitamins and lung cancer exists remains an open question. If they are responsible for the increase in lung cancer, Dr. Delmastro suggested a reason why.
“Probably it modifies, at least in smokers, some of the pathways in which carcinogens are metabolized,” Dr. Delmastro said. “In my view, however, smokers should not be taking anything other than, at most, a standard, one-a-day multivitamin.”
Dr. Delmastro said unless there is a specific medical reason you need to take high doses of specific B vitamins, you should avoid doing so. He added that not smoking or quitting smoking is the most important thing you can do to avoid lung cancer.
“I think anyone concerned about this issue should talk to their primary care provider, especially if they’re a smoker,” Delmastro said.
He added that the more information you can give your medical provider, the better that provider will be able to advise you on living a healthy lifestyle.