> Risk was further elevated in male smokers taking more than 20 milligrams of B6 or 55 micrograms of B12 a day for 10 years. 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.
Those are very high doses of each. An average multivitamin has 1.8 mg of B6 (vs. 20 mg in the study) and 6 mcg of B12 (vs. 55 mcg in the study).
I am surprised anyone wants to take that much, but I guess the smokers were trying anything they could (short of actually quitting) to compensate for the effect their habit has on their health.
I was referring to multivitamin levels which are typically ~100% RDA, so to get the levels the study considered harmful, you have to be intentionally taking large doses of B Vitamins which is easy not to do.
"Long-Term, High-Dose Vitamin B6/B12 Use Associated With Increased Lung Cancer Risk Among Men" (2023) https://cancer.osu.edu/news/long-term-high-dose-vitamin-b6-b... :
> Risk was further elevated in male smokers taking more than 20 milligrams of B6 or 55 micrograms of B12 a day for 10 years. 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.