However, we do know wheatgrass contains essential vitamins A, C, and E , as well as calcium, iron, and magnesium. Those are all things your body needs! So adding a little wheatgrass to your diet might be an easy way to get a bit more of those nutrients, especially if you're already a regular smoothie drinker. But you definitely can't rely on it for that — according to Alison Hornby , spokesperson for the British Dietetic Association, you can't count your wheatgrass shot as one of your daily five servings of fruits and veggies.