Doctors believe B vitamins may help prevent the DNA damage and gene mutations that can lead to cancer. In one study, researchers took blood samples from 385,747 people and followed up for 10 years. Scientists compared 899 people who developed lung cancer to 1,815 similar people who did not.
For vitamin B6, doctors found that compared to those with the lowest levels, people with the highest blood levels of vitamin B6 were 56 percent less likely to develop lung cancer. For the essential amino acid methionine, compared to those with the lowest levels, those with the highest levels of methionine were 48 percent less likely to develop lung cancer. In both findings, results were similar for current, former and non-smokers.