Chard is an incredibly nutrient dense vegetable. One cup cooked, provides only 35 calories and yet is an excellent source of vitamin A, vitamin C, vitamin E, vitamin K, riboflavin, fiber, calcium, iron, magnesium, potassium, copper, and manganese. One cup contains 716%(!) of the daily recommended value for vitamin K, a nutrient that plays an essential role in blood clotting and helps to build healthy bones. Chard also contains high amounts of beta-carotene, lutein, and zeaxanthin, which are all phytonutrients important for maintaining healthy vision, and possibly preventing cancer. (See more chard nutrition facts on Self.com.)