Vitamin K contributes to normal blood clotting in. Vitamin E helps to protect cells against oxidative stress. Vitamin C helps to reduce tiredness and fatigue. Riboflavin contributes to the maintenance of normal red blood cells in. Vitamin B6 contributes to normal protein. Vitamin B12 contributes to normal energy metabolism in. Pantothenic acid contributes to normal synthesis and normal metabolism of steroid hormones, vitamin D and in some neurotransmitters. Pepper extract - Improves the absorption of vitamins.