Your body needs a little dietary fat to absorb some of the vitamins found in dark green leafy vegetables. Add a bit of oil (such as olive or canola oil) or salad dressing to your dark green leafy vegetables to make sure your body absorbs all of the vitamins you eat. Many preparation methods and recipes for dark leafy greens already contain some type of fat such as oil, butter, or cheese in which case you don’t need to add any more to get those important nutrients.