吃下去之后还不是变成G P K......for your information:
http://en.wikipedia.org/wiki/Collagen
Synthetic pathogenesis
Vitamin C deficiency causes scurvy, a serious and painful disease in which defective collagen prevents the formation of strong connective tissue. Gums deteriorate and bleed, with loss of teeth; skin discolors, and wounds do not heal. Prior to the eighteenth century, this condition was notorious among long duration military, particularly naval, expeditions during which participants were deprived of foods containing Vitamin C. In the human body, a malfunction of the immune system, called an autoimmune disease, results in an immune response in which healthy collagen fibers are systematically destroyed with inflammation of surrounding tissues. The resulting disease processes are called Lupus erythematosus, and rheumatoid arthritis, or collagen tissue disorders.[7]
Many bacteria and viruses have virulence factors which destroy collagen or interfere with its production.
And most importantly
Collagen is the main protein of connective tissue in animals and the most abundant protein in mammals, [1] making up about 25% of the total protein content.