An often unexamined possibility is that vitamins are harmful in the long term. I recently dived into PubMed (and the hub) to see if there have been any studied

An often unexamined possibility is that vitamins are harmful in the long term. I recently dived into PubMed (and the hub) to see if there have been any studied deleterious effects of vitamins. There are many studies correlating intake of B vitamins (specifically B6 and B12) with all cause mortality, increased cancer incidence and aggressiveness, even when taken over a short period of time (6 months). D vitamin intake is also correlated with certain cancers after correcting for deficiencies. Even seemingly innocuous C vitamin intake at excessive doses (over 500mg) is correlated with with kidney disease and lung cancer. I'm just going by memory, but these were not single studies, but literature reviews. My suggestion is not to listen to me, but read studies, preferably lit reviews, of ANYTHING that you're considering consuming chronically. Another interesting tidbit: I found a study where individuals with certain vitamin or mineral deficiencies seemed to have lower mortality and lower cancer incidence. That one made me stop my vitamin intake definitely. I'm sorry for not including references, I'm on mobile, and not close to my Mendeley library, but you should do your own research anyways.