Nutritional Information: The onion is an excellent source of flavonoids and quercetin, two phyto-chemicals that help Vitamin C strengthen blood vessels, decrease inflammation, lower blood pressure and even inhibit the growth of tumor in the colon. Other minerals found in onions include phosphorous, magnesium, potassium, selenium, among others. Aside from calcium, onions have been newly identified to have a compound that inhibits Osteoporosis in women nearing their menopause. The anti-bacterial properties in onions would also help relieve urinary tract infection. Onions also relieve constipation and flatulence, arthritis and gout, cleanse the blood, and boost the immune system.