• Welcome to Phoenix Rising!

    Created in 2008, Phoenix Rising is the largest and oldest forum dedicated to furthering the understanding of and finding treatments for complex chronic illnesses such as chronic fatigue syndrome (ME/CFS), fibromyalgia (FM), long COVID, postural orthostatic tachycardia syndrome (POTS), mast cell activation syndrome (MCAS), and allied diseases.

    To become a member, simply click the Register button at the top right.

Long-Term, High-Dose Vitamin B6/B12 Use Associated With Increased Lung Cancer Risk Among Men

Dolphin

Senior Member
Messages
17,567

PatJ

Forum Support Assistant
Messages
5,288
Location
Canada
An important point left out of the headline is: "Male smokers taking B6 at this dose were three times more likely to develop lung cancer. Male smokers taking B12 at such doses were approximately four times more likely to develop the disease compared to non-users." (my bold)

If the study is accurate (it hasn't been replicated) then it's still an important finding but at the moment it only relates to smokers.
 

Hip

Senior Member
Messages
17,800
The study itself says:
Use of supplemental vitamins B6, folate, and B12 was not associated with lung cancer risk among women.

In contrast, use of vitamin B6 and B12 from individual supplement sources, but not from multivitamins, was associated with a 30% to 40% increase in lung cancer risk among men.

So it seems that multivitamin sources of B6 or B12 are safe; this increased risk only appears when these vitamins are taken individually. One might speculate that this may be due to a vitamin imbalance caused by taking individual B vitamins.


This paper says that the general lifetime risk of non-smokers developing lung cancer is 13/1000 for males and 14/1000 for females. So around 1 in 75 non-smokers will develop lung cancer in their life.
 
Last edited:

Dolphin

Senior Member
Messages
17,567
An important point left out of the headline is: "Male smokers taking B6 at this dose were three times more likely to develop lung cancer. Male smokers taking B12 at such doses were approximately four times more likely to develop the disease compared to non-users." (my bold)

If the study is accurate (it hasn't been replicated) then it's still an important finding but at the moment it only relates to smokers.
Abstract doesn't say risk is restricted to smokers.

J Clin Oncol. 2017 Aug 22:JCO2017727735. doi: 10.1200/JCO.2017.72.7735. [Epub ahead of print]
Long-Term, Supplemental, One-Carbon Metabolism-Related Vitamin B Use in Relation to Lung Cancer Risk in the Vitamins and Lifestyle (VITAL) Cohort.
Brasky TM1, White E1, Chen CL1.
Author information

Abstract
Purpose Inconsistent findings have been reported of a link between the use of one-carbon metabolism-related B vitamins and lung cancer risk.

Because of the high prevalence of supplemental vitamin B use, any possible increased association warrants further investigation.

We examined the association between long-term use of supplemental B vitamins on the one-carbon metabolism pathway and lung cancer risk in the Vitamins and Lifestyle (VITAL) cohort, which was designed specifically to look at supplement use relative to cancer risk.

Methods

A total of 77,118 participants of the VITAL cohort, 50 to 76 years of age, were recruited between October 2000 and December 2002 and included in this analysis.

Incident, primary, invasive lung cancers (n = 808) were ascertained by prospectively linking the participants to a population-based cancer registry.

The 10-year average daily dose from individual and multivitamin supplements were the exposures of primary interest.

Results

Use of supplemental vitamins B6, folate, and B12 was not associated with lung cancer risk among women.

In contrast, use of vitamin B6 and B12 from individual supplement sources, but not from multivitamins, was associated with a 30% to 40% increase in lung cancer risk among men.

When the 10-year average supplement dose was evaluated, there was an almost two-fold increase in lung cancer risk among men in the highest categories of vitamin B6 (> 20 mg/d; hazard ratio, 1.82; 95% CI, 1.25 to 2.65) and B12 (> 55µg/d; hazard ratio, 1.98; 95% CI, 1.32 to 2.97) compared with nonusers.

For vitamin B6 and B12, the risk was even higher among men who were smoking at baseline. In addition, the B6 and B12 associations were apparent in all histologic types except adenocarcinoma, which is the type less related to smoking.

Conclusion

This sex- and source-specific association provides further evidence that vitamin B supplements are not chemopreventive for lung cancer and may be harmful.

PMID:

28829668

DOI:

10.1200/JCO.2017.72.7735
 

PatJ

Forum Support Assistant
Messages
5,288
Location
Canada
Thanks for a good example of why it's important to read the study and not just a media summary. From the media summary I got the impression that only male smokers are at risk, but the study abstract explains that smokers are just at higher risk: "For vitamin B6 and B12, the risk was even higher among men who were smoking at baseline."

Edit: Cross-posted while Dolphin was writing a reply.
 

alex3619

Senior Member
Messages
13,810
Location
Logan, Queensland, Australia
One carbon metabolism allows protein modification for faster growth and repair. Cancers thrive under those conditions. Indeed some chemotherapy targets this metabolism, and so slows cancer growth. Note this is about cancer growth, not cancer initiation. If a cancer grows faster its conceivable that this will mean the immune system is less able to contain the cancer. Everyone gets cancer over time, most cancers are destroyed by the immune system before you even get symptoms.

This does need further investigation, and until then I consider it preliminary and not conclusive.

I am very interested in how they might account for the differences between males and females, if they can? Also how do they account for an increase in lung cancer and not other cancers?
 

alex3619

Senior Member
Messages
13,810
Location
Logan, Queensland, Australia
I am not be too worried about using methylation supplements at this point. If I still responded well to methylation then the small absolute risk would probably be worth it to me, even if this research is right. However as I stopped responding to methylation the risk is something I would have to consider if I were going to start methylation again. Its still one chance in hundreds though, if my wonky math skills did not fail me. Absolute risk and relative risk are not the same.

Putting this in perspective, a 2-4x risk for non-smokers is much smaller than about a 25x risk for smoking. For non-smokers, men also seem to have a lower risk than women for lung cancer.

See for example https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2764546/
Lung cancer incidence in never-smokers
Heather A. Wakelee,1 Ellen T. Chang,2 Scarlett L. Gomez,2 Theresa H. M. Keegan,2 Diane Feskanich,3 Christina A. Clarke,2,4 Lars Holmberg,5 Lee C. Yong,6 Laurence N. Kolonel,7 Michael K. Gould,8 and Dee W. West2,4
J Clin Oncol. 2007 Feb 10; 25(5): 472–478.
doi: 10.1200/JCO.2006.07.2983

The risk is very low for nonsmokers. Smokers might like to discuss this with their doctor, though its smoking that is the biggest risk.
 
Last edited: