What it does: Particularly important in childhood. Helps your body use essential fats, assisting in promoting healthy skin, hair and nerves.

Deficiency Signs: Dry skin, poor hair condition, prematurely greying hair, tender or sore muscles, poor appetite or nausea, eczema and dermatitis.

Best food sources: Cauliflower, lettuce, peas, tomatoes, oysters, grapefruit, watermelon, sweet corn, cabbage, almonds, cherries, herrings, milk, eggs.