High Dose B12 and Lung Cancer
Yesterday was a busy day. We usually get around 8-10 calls to our telephone helpline but yesterday we had only been open for two hours and already we had taken a dozen calls. And the reason for the increase in demand was a study that had been published in the United States that showed that men who take high doses of Vitamin B6 and B12 were nearly twice as likely to develop lung cancer compared to men who do not take high dose supplements. And that led to worried members of the PA Society contacting the helpline.
It took a while to find out more about the study from the Vitamins and Lifestyle (VITAL) cohort study and were published online August 22 in the Journal of Clinical Oncology, but by mid-morning I had located it and discovered a Medscape article written by Zosia Chustecka.
It appears that the Headlines dominating various social media sites which caused so much anxiety among members of the PA Society needed some explanation. The data collected by the researchers showed that “that taking high doses of B6 and B12 over a very long period of time could contribute to lung cancer incidence rates in male smokers”. So, if you are taking high dosage B12 and you are a smoker you may be four times at risk of developing lung cancer though surprisingly this only applies to males though there doesn’t seem to be any reason given for this.
So, it’s mainly smokers who are at risk: “Our study found that consuming high-dose individual B6 and B12 vitamin supplements over a 10-year period is associated with increased lung cancer risk, especially in male smokers,”
And, on top of this, Dr. Jennie Jackson, lecturer in human nutrition and dietetics at Glasgow Caledonian University pointed out “this was an observational study, and, as such, it cannot ‘provide proof of causation’. There may be an entirely different factor that is affecting the risk of cancer, which just happens to be related to supplement usage”. She suggests that in order “to prove that these vitamins directly cause cancer, an experimental design such as a randomized clinical trial would be needed.”
So, panic over – we patients who take large doses of B12 in order to carry on living stand a chance of developing lung cancer but, as long as you are not a smoker, you may not have to worry.
The study raises a number of questions, and one that needs to be explained is what type of B12 the participants were taking. It is well known that smokers taking Cyanocobalamin run the risk of developing serious optic atrophy if they already have Leber’s Disease so maybe, and I’m only saying maybe, it is the high doses of B12 as cyanocobalamin that is the problem. One thing is certain, patients with Pernicious Anaemia should not stop their treatment before discussing this with their doctor. As for me, well I don’t smoke and so I’m not going to be losing any sleep over this latest publication.