There are some caveats. The first is that the study only looked at individuals between the ages of 50 and 76, which means we don't know if the effects replicate in younger people. This is also an observational study—participants had to report their own habits, so we have to consider that they might have over- or underestimated their supplement usage. And while there are eight B Vitamins—B1 (Thiamine), B2 (Riboflavin), B3 (Niacin), B5 (Pantothenic acid), B6 (Pyridoxine), B7 (Biotin), B9 (Folic Acid), and B12 (Cobalamin)—the study only found risks associated with individual supplements of B6 and B12, and even then, that risk was exclusively in men who smoke. There was no association found in non-smokers, former smokers, men who only consumed vitamins B12 and B6 in the lower doses of a multivitamin, or in women.