It is also important to realize that minerals in the wrong form are toxic to the body. (read "supplements"..although clever marketers will try and convince us otherwise) Any other form than "food" will go against creating homeostasis.
A key to proper nutrition is life force energy. This distinction must not be missed. Most supplements do not contain much life force energy.
An interesting comment came from the guy who made using vitamin c therapy famous. Linus Pauling said that all (physical) disease is due to a lack of minerals. That is an important distinction. Ramp up this distinction further by realizing than no "product" will "save" you but that awareness of your holistic relationship will. Get your health from natural foods and lifestyle. Depending on a product is to be a victim.
But, seeing as this is the vitamin C "support" forum, I will say that vitamin C has helped and continues to help many people in the short term. It can be a great choice to help in situations where pathogens have overtaken due to a weak immune system. It will not correct the immune systme but it will buy some time until one gets back to proper principles. All vitamin c's are not eqaul due to processing. Do your homework. The more natural...the better.