Just one carrot supplies enough beta carotene for your body to convert into 1480mg of vitamin A (that’s plenty more than the daily recommendation of 800mg).
Both red and green peppers have twice the vitamin C content of oranges. Vitamin C is important for maintaining a healthy immune system.
Another veg with more vitamin C than citrus fruit, kale is also a marvellous provider of vitamin A d provides antioxidant vitamin E too.
We reccomend to eat a variety of protein daily (some at each meal) including seafood, lean meat, poultry, eggs, beans and peas, and soya products like tofu, as well as nuts and seeds.
It's not just greens, reds and oranges that help your immune system – mushrooms are a decent source of selenium and B vitamins too.
Tuna is a protein rich in selenium, which many people have in short supply in their diet
Garlic supposedly keeps away vampires but might also slightly up your odds against the common cold.