US National Library of Medicine
Medline Plus: Vitamin C
In addition to providing general information on vitamin C and its role in maintaining health, this article includes illustrated charts on the sources and benefits of vitamin C and the effects of vitamin C deficiency.
Other
Moms Team: u.s. Dietary Reference Intakes (Dr Is) for Vitamins
Find a chart with useful information on the vitamins you need to be healthy. Includes the "functions" and "sources" of vitamins C, B1, niacin, B6, folic acid, B12, A, D, E, and K.
Other
Doctor Yourself: What's the Difference Between Natural and Synthetic Vitamins?
Discusses the non-nutritional ingredients in vitamins and explains the differences between natural and synthetic vitamins. The examples of vitamins C and D are looked at in more detail.