When flu season strikes, keep your immune system strong with this citrus-infused cold-busting smoothie. This drink is packed with nutrients, and features two anti-inflammatory agents: ginger and turmeric. Citrus in the form of orange and lemon add a punch of vitamin C, which is a necessity this time of year. For a vegan version, simply sub the Greek yogurt with a dairy-free alternative, like cashew or coconut.