Go for fresh greens like baby spinach, kale, red or green leaf lettuce, rocket leaves to name a few. Loaded with minerals and vitamins, if you are trying to boost hemoglobin levels and improve blood circulation to the organs, then adding iron and folate rich leafy greens like spinach, kale, rocket leaves is a great idea. On the other hand red lettuce or green lettuce are loaded with fiber and cell regenerating antioxidants that are great for immunity and metabolism.