The present invention is directed to methods and compositions for the treatment of diabetes and related symptoms. It is more specifically directed to compositions including L-glutamine, its salts, or its derivatives, and uses of such compositions in the treatment of diabetes and related symptoms. In a method aspect, the present invention provides a method of treating diabetes. The method involves ingesting 0.05 g/kg body weight to 10.0 g/kg body weight of L-glutamine, an L-glutamine salt or an L-glutamine derivative per day by a person who has diabetes.