Salad greens, like other vegetables, are low in fat and calories, do not contain cholesterol and have a high vitamin and mineral content, making them disease-fighting, nutrient-packed powerhouses. In fact, a large, healthy salad can supply much of your daily vitamin and mineral requirement, according to Medline Plus. Choose a variety of greens for your salad, add other vegetables and toppings that are low in saturated fats, and nourish your body with natural, tasty vitamins.

Vitamin K

Green leafy vegetables are a source of vitamin K, which is necessary for blood to clot and may also contribute to bone strength in the elderly, according to Medline Plus. Because of its role in blood coagulation, vitamin K can interfere with blood-thinning medications such as warfarin, also known as Coumadin. If you take warfarin, consult your doctor about its interaction with vitamin K. Most leafy greens offer ample amounts of vitamin K, and both spinach and kale provide your entire daily requirement in a 1-cup serving.

Vitamin A

Vitamin A keeps skin and eyes healthy and helps regulate the immune system to prevent and fight off infections, according to the Office of Dietary Supplements. Plants contain the carotenoid form of vitamin A, the best-known and most efficient of which is beta-carotene. Most dark leafy greens offer some vitamin A, and a cup of either kale, spinach or romaine lettuce provides your entire daily intake requirement. Vitamin A is fat-soluble, so a bit of olive oil, cheese or salad dressing will help your body absorb it.

Vitamin B

Leafy green vegetables provide folate, or vitamin B-9, and vitamin B-6. Folate is necessary to make and maintain new cells--it helps make DNA and prevents DNA changes that could lead to cancer. Folate also helps make red blood cells and prevents anemia. Vitamin B-6 is involved with protein and red blood cell metabolism, nervous and immune system functions and maintenance of blood sugar levels. Kale is especially high in folate -- each cup offers 94 micrograms, or just shy of one-quarter of your daily needs.

Vitamin C

Humans do not make vitamin C within the body, so getting it from food sources or supplements is essential. Also known as ascorbic acid, vitamin C is necessary for wound healing. It is also an antioxidant that helps protect the body from damage caused by free radicals, which form when the body converts food into energy and may contribute to heart disease and cancer. Vitamin C improves iron absorption and is also involved in immune system function. Look to kale as an excellent source of vitamin C. Each cup contains 80 milligrams, which is more than the daily requirements for women and 89 percent of the requirement for men.