I love using a smoothie as a way to get extra nutrients into my diet. They are great as a snack or main meal (depending on what’s in it) if you are on the go or just don’t have the time to prepare a meal. Try my greens smoothie for the extra vitamin/mineral nutrient kick. I much prefer smoothies to juices as you are not losing out on any of the fibre from the fruit or vegetable.
1 handful baby spinach
1 chunk of cucumber 
1/2 avocado 
1 kiwi fruit
1/2 apple
1 teaspoon barley grass powder
200ml coconut water (or water if you are trying to keep the sugar content down)
1/2 cup of ice
Add everything to a blender and blend - that simple. 
If you would like to add protein to it - I would suggest a plain plant based protein powder.