Collagen: Collagen is one of the most important proteins in the body because it is essential for bone, joint, hair, skin, and nail health. By the age of 40, collagen in our bodies has reduced by about 25 percent. There are many supplements out there containing type I, II, and III. Type I and III are necessary for skin, nail, and bone health while type II supports cartilage and joint health. Therefore, make sure to select the supplement that best suits your needs and that the supplement comes from a reputable source. Another alternative is bone broth as it contains many beneficial nutrients as well as collagen.