200 mg / day of Vitamin C from fruits & veggies reduces stroke risk. Supplements not effective (for reducing stroke risk anyway).
Mostly that supplements don't do much with some exceptions. Vitamin D important IF you're already low but can be harmful if you don't need it. Didn't see Vitamin B12 mentioned. To sum up, get vitamins from the food you eat and not supplements. The body better regulates their absorption in food but not so well regulated as supplements.
Need Folate, B12, B6 to help metabolize/reduce homocystine levels in blood. High homocystine levels correlate with brain atrophy, alzheimers, etc.