WASHINGTON — Men who take too much vitamin B-6 and B-12 over long periods of time “dramatically” increase their risks of developing lung cancer, according to a new study from Ohio State University’s Comprehensive Cancer Center.
Men who took dietary supplements containing high doses of B-6 and B-12 for at least 10 years approximately doubled their risk of developing lung cancer, said Theodore Brasky, the Ohio State researcher who led the study, in a news release.
The risks of developing lung cancer were even higher for men who take the supplements and also smoke, according to the study, which was published this month in the Journal of Clinical Oncology.
The study tracked 77,000 patients age 50 to 76 for more than 10 years.
Researchers said there was no increased risk of lung cancer in women who took high doses of vitamin B.
B vitamins, such as B-6 and B-12, are some of the most popular dietary supplements sold in the U.S. They’re often marketed as products that can boost energy levels.
The recommended daily intake of B-12 is less than 2 micrograms and about 1 and 1/2 milligrams for vitamin B-6, according to researchers.
“But if you look at these supplement bottles, they’re being sold in pill form at up to 5,000 micrograms per dose, which is much, much higher than the daily recommended amount,” Brasky said.
Brasky said people can easily get enough vitamin B from eating meat, chickpeas and cereal fortified with the vitamin. “So there really is no reason to supplement your vitamin B intake at these levels, and certainly not for years on end,” he said.
In a statement, the Council for Responsible Nutrition, a trade association for the dietary supplement industry, said the study doesn’t prove that high vitamin B intake causes lung cancer and that the results conflict with other studies measuring vitamin B and lung cancer risk.
“We urge consumers to resist the temptation to allow sensational headlines from this new study to alter their use of B vitamins, especially without further understanding of the nature of this study and a conversation with their health care practitioners,” Duffy MacKay, senior vice president for scientific and regulatory affairs, said in a statement.