Can vitamin B12 actually cause lung cancer? Research out of Norway seems to think that it can.
One article (1) looked at vitamin B12 and its ability increase the rate of lung cancer. They cited a study out of Norway that indicated a higher risk of both death and lung cancer in those patients who took vitamin B12 supplements. According to the study, nearly 7000 patients were treated with vitamin B12 supplements for 3-4 years.
The idea behind the study was to actually see if taking the vitamin could prevent heart disease. Not only didn’t it help decrease the risk of heart disease but it increased the chances of getting lung cancer. Those took vitamin B12 and folate had a 21 percent increased chance of getting cancer and a 38 percent chance of dying from the condition.
Source: 1.Folic Acid, B12 May Increase Cancer Risk. http://www.webmd.com/cancer/news/20091117/folic-acid-b12-may-increase-cancer-risk. Accessed 9/13/16.