Dr. Holick is internationally recognized for his expertise in the fields of vitamin D, acquired and heritable disorders of metabolic bone disease and collagen-related disorders. He has provided guidelines for how to determine, treat and prevent vitamin D deficiency and has provided insights into the genetics of Ehlers Danlos syndrome hypermobility type. He has pioneered research in how vitamin D can be useful in treating and preventing infectious diseases and autoimmune disorders. He has published over 900 manuscripts, reviews, chapters and has written and/or edited 15 books.  Recognized by Google scholar more than 150,000 times.