Over the last decades a considerable amount of data has accumulated to indicate that metabolic and endocrine alterations of diabetes affect bone quantity and quality. These skeletal changes may increase the risk of bone fracture. There is strong evidence that in type 1 diabetes the decreased bone mass, lack of insulin and insulin-like growth factor-1, dysregulation of adipokines, and increased levels of proinflammatory cytokines are in the background of fragility fractures. In type 2 diabetes hyperinsulinemia, insulin resistance and increased body weight may result in an increase of bone mass; however, accumulation of advanced glycation end products within the bone collagen driven by glucotoxicity may increase the cortical porosity. There is a higher incidence of falls resulting from diabetes-related co-morbidities such as diabetic retinopathy, peripheral neuropathy, hypoglycemic episodes and sometimes from the medications. Vitamin D deficiency has special impact on glucose metabolism and the prevalence of diabetes. Vitamin D supplementation in childhood can decrease incidence of type 1 diabetes by 80%. The effect of thiazolidinediones, glucagon-like peptide-1 agonists and metformin, agents for treatment of diabetes open a new connection between bone, carbohydrate and fat metabolism.