Green onions, also known as scallions or spring onions, contain a wide variety of health-enhancing
compounds like vitamins, minerals and phytochemicals. A single, 12-gram green onion stalk contains nearly 20 micrograms of vitamin K and 1.6 milligrams of vitamin C. For a healthy adult man, this supplies 16 percent of his recommended daily allowance of vitamin K and nearly 2 percent of his vitamin C RDA. For a woman, a green onion stalk provides 22 percent of her daily vitamin K and 2.1 percent of her vitamin C. Both vitamins K and C are crucial for the growth, development and maintenance of strong bones. A green onion stalk contains 24 micrograms of vitamin A in the form of pro vitamin A carotenoid compounds that the body converts to retinol, the active form of the vitamin. The vitamin C and vitamin A found in foods like green onions have strong antioxidant properties. A diet rich in foods with a high antioxidant concentration – primarily fruits and vegetables – is linked to a decreased risk of heart disease. Vitamin C may also help prevent high blood pressure, which, in turn, can lower your risk of heart disease.