What is Doctor’s Best Sustained Release Vitamin C with PureWay-C? Doctor’s Best Sustained Release Vitamin C with PureWay-C is a unique formula that supports the body’s immune system. It contains PureWay-C, a unique form of vitamin C that contains vitamin C-lipid metabolites that has superior uptake, bioavailability and retention in cells, as well as more potent free radical scavenging capabilities than other forms of vitamin C. The increased bioavailability from PureWay-C means has a greater potential than other forms of vitamin C to support healthy neuron function and enhanced immune system activity. The formula also contains citrus bioflavonoids and ascorbyl palmitate, a fat-soluble form of vitamin C that is able to be stored in lipid cell membranes for later use. Bioflavonoids work in conjunction with vitamin C to improve absorption and boost its free radical scavenging effects. How does it work? PureWay-C is a novel vitamin C preparation containing vitamin C-lipid metabolites. Studies in the laboratory show that human cells absorb this new form of vitamin C more rapidly and in greater amounts than the three most popular forms of vitamin C: ascorbic acid, calcium ascorbate and calcium ascorbate-calcium threonate-dehydroascorbate. In order for vitamin C to exert its antioxidant benefits, it must be able to get inside cells. PureWay-C was tested for its ability to be taken up and retained in the cell. Compared to ascorbic acid, the most common form of vitamin C, PureWay-C showed a 233% increase in cellular uptake into human T-lymphocytes at both 30 and 45 minutes. This absorption level was a 122% improvement above the next best form of vitamin C, calcium ascorbate-calcium threonate-dehydroascorbate.