If your unable to maintain a healthy diet, then your body will quit repairing unnecessary things and only maintain brain and heart functions. All the nutrients go their first and will be used up before it can be released to the other areas. Taking a multivitamin along with protein can significantly help your body. I eat clean but not real clean. I also workout. Giving your body that extra availability lets it relax and the nutrients are spread out more evenly. If everything is healthy and functioning normally, your ok, but any injuries or illnesses reduce your abilities. I believe in using a great protien and a great multivitamin. I would rather have full availability of all my vitamins, nutrients and amino acids to use up as I see fit, rather than rely on my body to designate its use. It just depends on what you, yourself, see. A fully healthy body can still use a little help. That's my opinion, not fact. Just reasoning lol. I like these conversations. I always learn something new.