Romaine lettuce is SUPER loaded with Vitamin K (potassium) at 107% of the %DV in a 2 cup serving. Vit. K has been shown in numerous studies to be useful in lowering high blood pressure, a risk factor for heart disease. 45% of Vit. A! 32% of Folate. 8% of fiber which adds another plus in its column of heart-healthy effects. In the colon, fiber binds to bile salts and removes them from the body.