Vitamin B supplements might be doing you more harm than good. Excessive amounts of vitamin B6 and B12 may pose health risks, new research suggests.
Men who take vitamin B6 and B12 supplements daily over a long period of time are doubling their risk for lung cancer and tripling their risk if they smoked, says new research from Ohio State University.
The study followed more than 77,000 participants aged 50-76 who took these specific B vitamins daily over a 10-year period.
“High-dose B6 and B12 supplements should not be taken for lung cancer prevention, especially in men and they may cause harm in male smokers,” said study lead author Theodore Brasky. He is a research assistant professor at Ohio State University.
Brasky and colleagues conducted what they described as the first prospective, observational study to examine the effects of long-term, high-dose vitamin B6 and B12 supplement use on lung cancer risk.
The researchers determined that men who now smoked and reported taking more than 20 milligrams (mg) of vitamin B6 daily during the 10-year period leading up to the study were about three times as likely to develop lung cancer than current smokers who didn’t use B6 supplements at all.
Vitamin B is found naturally in most foods we eat, including animal products like fish, meat, eggs and dairy, fruits and vegetables, whole grains, soy milk and beans.
Since vitamin B is already found in food, the study noted that B6 and B12 supplements meant participants were receiving the vitamins in doses much higher than the recommended limit, 1.3 milligrams is the daily recommended dose for B6 and 2.4 micrograms is the recommended daily dose for B12.
However, the study wasn’t designed to prove cause-and-effect between the vitamins and lung cancer, it only showed an association.
It’s also not clear why only men and current male smokers seem to face an extra risk.
The only reason to take high doses of vitamin B is if you are diagnosed with a deficiency, she said.
The study was published in the Journal of Clinical Oncology.