What's a good amount of B-vitamins and D3 (I assume this is a form of vitamin D) to take?

My approach to nutritional supplements is that they are supplements - I should be getting most of my dose of required vitamins and minerals from my diet, and the pill is just an insurance policy. Are you suggesting that I need more than my normal diet + the vitamin combined provide?

Is there a book or a Web site with concussion nutrition that you can recommend?