Intravenous therapy was expanded by Italian physician Guido Baccelli in the late 1890s and further developed in the 1930s by Samuel Hirschfeld, Harold T. Hyman and Justine Johnstone Wanger but was not widely available until the 1950s. In the 1960s, the concept of providing a person's complete nutritional needs through an IV solution began to be seriously considered. The first parenteral nutrition supplementation consisted of hydrolyzed proteins and dextrose. This was followed in 1975 with the introduction of intravenous fat emulsions and vitamins which were added to form "total parenteral nutrition", or that which includes protein, fat, and carbohydrates.