Over 50% of proteins in the body are glycoproteins so yeah it is important. egg shell membrane contains all glycosaminoglycans, and 8 "essential" sugars. Soup bones, and other bones used to make bone broth contain them too. I ate a bunch raw tonight to maximise nutrition. Tasted great. Other sources of all of them may be shark cartilage, and squid/octopus. And pig skin. Most commercially bone broth comes from pig/cow skin per the wiki page on it.