GNC Vitamin B-12 - 500 Mcg: Carbohydrate Metabolism And Energy Support Vitamin B-12 Is Essential For Carbohydrate Metabolism & Energy Production And Is Required For Red Blood Cell Formation. GNC's Vitamin B-12 - 500 Mcg Is Kosher And Gluten Free. Contains A 100-Day Supply Of 100 Vegetarian Tablets No Artificial Colors Or Flavors No Preservatives, Wheat, Soy, Or Dairy Sodium Free | GNC Vitamin Bvitamin B -12 500 Mcg Vitamin B - 100 Tablets (100 Servings) Vitamin B - 100 Vegtarian Tablets