Among men, taking B6 and B12 from only individual supplement sources was associated with a 30% to 40% increase in risk for lung cancer.
"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. CNN reports the participants with the highest risk of lung cancer were smokers who use vitamin B supplementation. Previous trials investigating the association of increased risk of lung cancer and vitamin B supplementationhave returned mixed results.
Brasky notes these findings relate to doses that are well above those from taking a multivitamin every day for 10 years.
Researchers from Ohio State University and the National Taiwan University studied more than 77,000 people aged between 50 and 76 in the USA and found that men who took high dosages of vitamins B6 and B12 faced 30 percent to 40 percent increased risk of lung cancer. These levels were more than 11 times the recommended daily amount of B6 and 23 times that of B12. This is the first study to prospectively examine the effects of extended, high-dose B6/B12 supplement use and lung cancer risk. The results of this study indicate that men taking vitamin B supplements are at a higher risk of developing lung cancer. The participants were from the Vitamins And Lifestyle cohort, which was set up to evaluate vitamin and mineral supplements and their relationship with cancer over the longer-term.
If you look at B-vitamin supplement bottles...they are anywhere between 50-fold the USA recommended dietary allowance (to) upward of 2,100-fold. An average healthy body will flush out any excess, unneeded vitamin B, so taking a higher dose probably doesn't provide much benefit.
Until more research is completed, there is no conclusive link between high doses of vitamin B and lung cancer.
Over recent years, a number of studies have looked for links between lung cancer and B vitamins.
The study involved around 77,000 adults in Washington state ages 50 to 76, including 139 cases of lung cancer among 3,200 male smokers.
Taking these supplements has previously been shown to have a protective effect against lung cancer, but the authors of the current study say this appears to be a double-edged sword. "I think that the door remains open on that". These supplements have been broadly thought to reduce cancer risk.
He went on to explain that the "use of combustible tobacco is a far more important factor in lung cancer development in both men and women".