Classified as a cruciferous vegetable, this brother of broccoli has a leg up on lettuce. Arugula contains about eight times the calcium, fives times the vitamin A, vitamin C and vitamin K, and four times the iron as the same amount of iceberg lettuce—not to mention more fiber, folate, protein, potassium and magnesium. Add it up and arugula can help defend against heart disease, osteoporosis, sun damage and certain cancers. Arugula has a peppery, slightly bitter taste and can be used in salads or even to make pesto. Two cups = 60 mg of calcium.