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When it comes to vitamin supplements, it’s possible to take too much of a good thing.
A new study has found that consuming too much of vitamins B6 and B12 could greatly increase lung cancer in men.
The study, published this week in the Journal of Clinical Oncology, looked at 77,000 patients ages 50 to 76 over the course of 10 years and found that men who took high doses of B6 and B12 doubled their risk of getting lung cancer. For those men who were smokers, their risk increased four times. Women who took the same amount of vitamin B didn’t see any increased risk.
“I think these results point to a synergism” between high-dose B vitamins, smoking and lung cancer risk among men, study author Theodore Brasky, an epidemiologist in the Division of Cancer Prevention and Control at the Ohio State University College of Medicine, told CNN.
Other researchers have found different results, CNN said. For example, some studies linked B6 with a lower risk of lung cancer.
Why the discrepancy?
The authors of the new study said it's maybe because some studies measure B vitamins in the blood and not through dietary surveys, as they did. Or maybe it's because lung cancer raises levels of vitamins in someone’s body.
For those taking multivitamins — not high-dose supplements that go beyond recommended levels — no link has been found to the risk of cancer.