The vitamin B-complex are essential water-soluble vitamins, including vitamin B1(thiamine), vitamin B2 (riboflavin ), vitamin B3 (niacin), vitamin B5 (pantothenic acid), vitamin B6 (pyridoxine), biotin, folic acid and vitamin B12 (cobalamins). A. Vitamin B1 (Thiamine) Vitamin B1 and glucose metabolism and vascular disease Thiamine is an essential cofactor in carbohydrate metabolism and individuals with diabetes …