Vitamin C has proven effective at assisting our bodies to ward off illnesses and generally promoting a healthy immune system. Many people need to be getting between 65 and 90 mg of vitamin C a day, but some take as much as 1,000 to 2,000 mg a day in an effort to boost the immune system. Why is this? Interestingly, many supplemental products don’t contain the necessary additives to allow the vitamin to be properly absorbed in the body. The answer to properly metabolizing vitamin C (and other valuable nutrients) lies in solubility.