Abstract

Introduction

Diabetes is a chronic metabolic disorder which is linked to energy metabolism, particularly carbohydrate and fat.  Obesity and physical inactivity are shown to be the major risk factors for type 2 diabetes (T2DM). Oxidative stress may also contribute to increase in blood glucose levels, thus contribute to the pathogenesis of T2DM by increasing insulin resistance or impairing insulin secretion.^[1] The consequences and complications of diabetes are due to imbalance between free radical formation and their control by natural antioxidants.^[2] Thus nutrients having antioxidant function are important in disease development and control also non oxidant vitamins have also shown relationship with diabetes.^[3] Long-term treatment of diabetic patients with metformin may cause a higher risk of developing vitamin B-12 deficiency.^[4] Vitamin A plays important role as antioxidant, thus helping to maintain the organism’s homeostasis when subjected to various forms of stress.^[5] Vitamin B₆ consists of a group of three compounds: Pyridoxal, pyridoxine and pyridoxamine, and their corresponding phosphorylase forms and the active form of this vitamin is pyridoxal-5’-phospate (PLP).  In new diabetic patients lower PLP concentrations were found as compared to non-diabetic persons.^[6] Niacin or B₃, Nicotinic acid is a component of NAD and NADH, which are essential for ATP production and energy efficiency at the cellular level and has been found to increase HDL-cholesterol, decreases TG and LDL cholesterol.^[7] As T2DM is an oxidative stress disease; vitamin B₁₂ and folic acid deficiencies in diabetic subjects have been found associated to oxidative stress so it is conceivable that vitamin B₁₂ deficiency should be considered a risk factor for diabetic complications.^[8] Plasma vitamin C concentrations have been inversely correlated to glycosylated hemoglobin and fasting and postprandial blood, Vitamin C has also been shown to reduce anxiety levels.^[9] and supplementation for 3 months of vitamins C and E decreases hypertension, blood glucose while increasing superoxide dismutase and glutathione levels.^[10] Vitamin D may play an important role in modifying the risk of diabetes.^[11] The role of vitamin D in the function of pancreatic cells can be mediated by the union of 1,25-dihydroxyvitamin D to its receptors in the beta cell.^[12]