None!!!
What would they do for you? Food is nutrition and by definition, its simply what you need to stay alive and working properly. Just like how a car needs gasoline and an occasional oil change, we have requirements of our own.
Those requirements come from the food that we eat!!!
What will a supplement provide for you that regular food will not? Here's a test. Look down at your belly. Is you're tummy flat? Or do you have extra flab on your abs? If the later is true, that means you are overly nourished and don't need anything extra.
What to know who has real deficiencies? These starving kids in Africa!!! Look:
https://www.google.com/search?q=star...OuPA0AGgrYGgDQ
They have nutritional deficiencies. You don't. The only reason why you think you need supplements is because the supplement companies are good at advertising and getting you to believe that you need their products when in reality you are perfectly healthy and living well.
By the way, this reminds me of a few guys I overheard in the gym the other day, regular fitness buffs (not competitive athletes), talking about steroids, and the one guy was complaining that his legs were too weak. It really upset me. You mean to tell me that these guys had to take illegal drugs just to get half way descent bodies? Why not work hard? Last time I knew, hard work actually works.
Pardon me for getting off on a rant. But I hate supplement companies and advertisements. Because they only operate on getting you to believe that you need their products for some reason, useless products mind you. That's fine if it does what's necessary to make them rich, even if that means taking advantage of gullible people. But realize by buying into their sales tactics, you're also buying into the belief that you can't do it on your own. As if nobody has ever had a good body or been healthy before the invention of supplements? Come on!! It's a big crock!!!
Let's really think about what this country has turned into over the last several decades. My grandmother used to always tell me how nutritious foods such as fruits, vegetables, and liver was for you. But now? A lot of people are so stupid that they don't even know what fruits and vegetables are. They think it's cool aid and fruit roll ups. Now they think healthy food is nutrigrain bars; it must be because its in the name, right? Eat pop tarts and frosted flakes, and a starbucks mocha for breakfast, a nutrigrain bar for snacks, McDonalds for lunch, Pizza for dinner, (don't forget your ice cream snack latter on), but as long as you have a vitamin pill you'll be ok. Maybe even throw in some ritalin, prozac, lipitor, and viagra for safe measure.