Vitamin B6 and B12 have been previously found to have a protective effect against the disease but researchers who studied more than 77,000 people in the US concluded it appeared to be a “double-edged sword”.
Taking supplements containing thousands of times the recommended daily dose over a period of 10 years was associated with a 30 to 40 per cent increased the risk of lung cancer, but only among men, not women, they found.
However other experts commenting on the research suggested the findings had been “over-dramatized” and should be taken with a “pinch of salt”.
The researchers, from Ohio State University and the National Taiwan University, pointed out that most Americans already received enough vitamin B in their diet and so did not need to take more.
The people in the survey may have been taking extra vitamins in the belief that it would help stave off cancer. But the researchers wrote in the Journal of Clinical Oncology: “These B-vitamins may have a ‘double-edged sword’ effect on lung cancer in possessing dual … effects that [are] time and dose-dependent.
More of this news at Independent UK