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Can B6 And B12 Increase Your Risk Of Lung Cancer?


For many men, a quick vitamin supplement in the morning is the norm. However, research has found a link to increased risk of lung cancer for men who smoke and take vitamin B12 or vitamin B6 supplements. And, the increase is startling.

The study, conducted over a two-year period, focused on 77,000 white men between the ages of 50 and 76. Of those, roughly 3,200 were smokers. The study found a 30 to 40 percent increase in lung cancer risk for men taking vitamin B6 or vitamin B12 supplements.

What does vitamin B do?

Vitamin B is a family of 8 vitamins. Each one dissolves in water and plays an important role in cell metabolism, which simply means the processes needed to maintain life. B12, for example, helps keep nerves and red blood cells healthy, according to the National Institutes of Health.

Both B6 and B12 occur naturally in meat, liver, eggs and milk, and the NIH has recommends that adults get 2.4 micrograms (mcg) per day. As an example, USDA data shows a 3-ounce cooked filet of rainbow trout has 3.49mcg, and cheeseburger from a fast food restaurant has 0.69mcg

However, there is another source many people take every day: Dietary supplements.

Dietary supplements

Many people take dietary supplements to help them get the nutrients they need. Others take supplements for real or perceived health benefits. With B6 and B12, people believe it gives them a boost of energy, even though there is no evidence of it.


While a multivitamin tends to stay close to the recommended daily allowances, supplements containing only B12 or B6 go well beyond the recommended dose. The next time you stop at your favorite grocery store, pick up a bottle of vitamin B12 and read the label. You could easily find one offering 50 times the recommended daily amount.

And, that is the important piece to the study.

What do you need to know about this study?

Dr. Santosh Rao is the medical director of integrative medicine at Banner MD Anderson Cancer Center. He noted two important pieces of information within the study:

  • The study showed an association with high-dose B6 and B12 supplements in male smokers. Multivitamins did not seem to have an effect. And, women did not see an increase.
  • Similar studies conducted previously have been mixed, and this particular study was done by survey and not through conventional blood testing.

“I think the take-home point, as in some previous studies in smokers, is I wouldn't take additional vitamins beyond the RDA,” Dr. Rao said. “Most Americans get plenty of B12, unless they're vegetarian, and a daily multivitamin is enough.”

Dr. Rao also does not recommend people take a lot of B6, either. Instead of using high doses of vitamins B6 and B12 to boost your energy, Dr. Rao suggests quitting smoking.


“I think the study raises the concern that, in smokers, for unknown reasons and mechanisms, there may be an association with B6 and B12 and lung cancer if you take a ton of it for ‘energy boosting,’” Dr. Rao said.

To help evaluate your personal risk for lung cancer, talk with a Banner Health specialist


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