Vitamins
An 8 oz. of sirloin steak is not only a good source of fat and proteins, but it also doesn't fail to provide the body with the essential amount of vitamins. The sirloin steak provides around 4 mcg of vitamin B12, 19 mg of niacin, 1.5 gm of vitamin B6 and 0.35 mg of riboflavin. It also contains other essential vitamins like vitamin K, E, pantothenic acid, thiamine and folate.