I recommend you consider purchasing a paperback called "What You Must KNow About
Vitamins, Minerals, Herbs & More" by Dr. Pamela Wartian Smith, M.D., MPH.

It contains data on all the vitamins, giving you a section adjacent to the description
which explains the illnesses that vitamin may help target. For example, niacin is
helpful in brain function, so is Folate, in fact, the whole B series is beneficial for
brain functioning and calmness.

But if one is contraindicated for any illness or interacts in a negative way with your
medication, you are told that, also.

I refer to it often when I'm trying to answer a question for myself or someone else.