Knowing the facts about how and where food is grown or how animals are raised and how polluted the air and waters are the only conclusion you can come to about eating and getting all the nutrients you need would be supplementation. Sports nutrition companies have been doing scientific research on their products for years knowing you can't be an outstanding athlete and just eat food. Natural bodybuilders for example burn a lot of calories each day sometimes between 6-8000 calories a day. Breaking that down into digestible meals every 2-3 hours is difficult without the use of high density supplements that break down and digest rapidly and get into their system to feed the muscle cells.
Their are protein supplements and carbohydrate supplements. Vitamins and mineral supplements. To use these supplements effectively you must have knowledge of how your cells utilize nutrition. You must study! Only then should you be spending your hard earned money on supplements. Know what vitamins do. Know what minerals you need. Know how much protein you require to keep what muscle you do have and how much more you need to build muscle. Know how many carbohydrate grams it takes to give you energy to train or how many fat grams your body needs a day. The knowledge on these areas are vast and it takes perseverance to know how to keep your body running in a healthy state.
Exercise is important but I would have to say that nutrition takes top billing and is the key to health. People just walking, and eating a well balanced diet may not have to supplement like someone doing advanced training exercises. I would not trust my health totally on food. I supplement daily and try to eat as good as possible and I still come up deficient in some areas. As you age supplementation becomes more important than ever. It is harder to digest certain foods and get the nutrients into your system. Talk to a professional and see what supplementation can do for you. Thanks Reid.