This article does a great job of talking about supplements and their role in overall nutrition. The best part of the article is where the break down by age (20's, 30's, etc) what supplements these particular age groups need, what is optional and breaks it down by gender. They also include optional supplements for these age ranges and say when it might be a good idea to consider this optional supplement. Age ranges go up to 50 and there is a catch all group at the bottom that includes all ages and what supplementation might be good to take.