(HealthDay News) — Men, and especially male smokers, appear to be more likely to develop lung cancer if they take high doses of vitamins B6 and B12, according to a study published online Aug. 22 in the Journal of Clinical Oncology.
The research included 77,118 adults, aged 50 to 76, in Washington state. The participants were recruited from 2000 to 2002, and answered questions about their vitamin use over the previous 10 years. The researchers found 808 of the study volunteers developed lung cancer over an average follow-up of six years.
“We found that men who took more than 20 milligrams per day of B6 averaged over 10 years had an 82 percent increased risk of lung cancer relative to men who did not take supplemental B vitamins from any source,” lead author Theodore Brasky, Ph.D., a research assistant professor at The Ohio State University College of Medicine in Columbus, told HealthDay. “Men who took more than 55 micrograms per day of B12 had a 98 percent increased lung cancer risk relative to men who did not take B vitamins.” Men who smoked at the beginning of the study period and consumed high levels of the B vitamins were three to four times more likely to develop lung cancer, he added.
“This sex- and source-specific association provides further evidence that vitamin B supplements not chemopreventive for lung cancer and may be harmful,” the authors write.