Lettuce

Almost all of the lettuces are low in calories and high in fiber, and provide vitamins A, C, and K; B vitamins thiamine, niacin, pantothenic acid, and folate; carotenes, including beta-carotene, lutein, and zeaxanthin; and the minerals manganese, potassium, and iron. The traditional iceberg lettuce is the least nutrient-dense of the lettuces. Romaine is probably the richest nutrient source among them; it is an excellent source of vitamins A, C, and folate, as well as the minerals manganese and chromium. It also provides vitamins B1 and B2, potassium, molybdenum, iron, and phosphorus. Many of the leaf lettuces offer nearly as good a nutrient profile as romaine, so you don’t need to give up variety.
The mix of minerals, fiber, and antioxidants in romaine help it lower blood cholesterol and reduce the formation of fatty plaques in arteries. The potassium and other minerals help lower blood pressure, and the B vitamins help support and increase your metabolism.
Nutritional Facts :
One cup of shredded raw romaine provides 8 calories, 1.4 g carbohydrate, 1 g protein, 0.2 g fat, 1 g dietary fiber, 1456 IU vitamin A, 14 mg vitamin C, 76 mcg folic acid, 162 mg potassium, 4 mg sodium, 26 mg phosphorus, 20 mg calcium, and 4 mg magnesium.