Obesity, induced by unhealthy lifestyle choices, could be involved in the development of chronic diseases like type 2 diabete. Obesity is largely due to the imbalance of energy intake and expenditure, therefore we have put more emphasis on the amount of macronutrients including carbohydrates, fats and proteins as dietary therapy for obesity and related-conditions. On the other hand, several studies revealed obese or diabetic patients were more likely to have micronutrient deficiencies such as vitamins and minerals. Besides the effects on bone metabolism, vitamin D and calcium might contribute to metabolic disorder accompanied by obesity. However, it has not been concluded supplementation of these two nutrients has a benefit in obese or diabetic individuals. Further studies are needed.