Proteins are necessary for tissue repair and for the construction of new tissue. Every cell needs protein to maintain its life. Protein is also the primary substance used to replace worn out or dead cells. Your muscles, hair, nails, skin, and eyes are made of protein.
Taking supplemental chromium has been shown repeatedly to improve insulin sensitivity and glucose tolerance, even to the point of reversing type II diabetes in many people (1). Thus, as my old clinical nutrition professor pointed out, apparently a chromium deficiency can actually lead to type II diabetes.
It may be easier to understand the importance of insulin therapy if you understand how insulin normally works in the body and what happens when you have diabetes. Regulate sugar in your bloodstream. The main job of insulin is to keep the level of glucose in the bloodstream within a normal range. After you eat, carbohydrates break down into glucose, a sugar that serves as a primary source of energy, and enters the bloodstream.