Spinach is a rich source of vitamins K, A and C. Vitamin K is important for maintaining bone health; vitamin A boosts vision and the immune system and vitamin C helps heal wounds and maintain strong bones and teeth. Spinach also contains folic acid, manganese, zinc, magnesium, calcium and iron. In fact, there are few foods that offer a more powerful combination of vitamins and minerals. A cup of raw spinach has less than 10 calories and is low in saturated fat and cholesterol. Nutrient dense and tasty, too spinach also offers protection against certain types of cancers and cardiovascular problems.