Also folate intake can mask B12 deficiency so it is always good idea to have buffer of Vitamin B12 in your body when starting on iron supplementation. The food will rarely help as in most cases B12 deficiency is not because of less B12 rich food is eaten but because our body can't absorb it properly. So sublingual and intramuscular intake is preferable.
For which reason, in spite of the potential inconclusiveness of these results, I am mildly concerned about the parent subject.
I used to be a smoker. After quitting and having some tests done by my doctor he said that my lungs should be back to functioning/health as if I'd never smoked inside of 4-5 years (so long as I didn't relapse. That hasn't been a problem). We didn't discuss chances of lung cancer in spite of that. If it's true that the supportive effects of B12 supplementation even on ex-smokers exponentially increases chances, then it becomes even more concerning.
