And can not truly be answered with any certainty because we don't fully understand what is happening in compromised cellular respiration in dopaminergic and other high energy neurons. You will hear different opinions based on many ideas. B vitamins should be taken very day, but read all about them by doing a search, the info that you get can be confusing. I take a b12 multi without more than 300 mg of B6' we need all the b vitamins because like vitC the bs are water soluble and you need to replenish them often. But there is evidence that the bs 1 and 6 can interfere with the others absorption and are liver toxic. Antioxidants of any kind are ok, just don't go overboard. 200 mg of Co-Q, up to 500 mg of c per day, circumin, Astaxanthin,resveratrol, etc.,bioflavonoids can't hurt but remember you can get too much of a good thing. Vit A we rarely need except if you are"nt getting enough in your diet and have night vision problems.Vit d is very important for bone health and I take 2000 IU a day in the winter or any day I get no sunlight. Otherwise Vit d is not needed,like in the summer if you get out. Always your supplements with a bit of food to promote absorption and minimize stomach upset. If you don't have a good feeling about your supplement regimen, do more research.this is just a beginning blog about supplements. We do need some, we may need more of others, we may be doing harm with some. You have to dig deep to find what your body is best responding to