DEAR MAYO CLINIC: Growing up, I was told to drink orange juice when I had a cold because “vitamin C is the cure.” Does vitamin C actually help us when we’re sick? What are its benefits? ANSWER: Vitamin C supports our immune systems, helps our bodies heal wounds, protects our joints and contributes to collagen formation, the main protein in the body. Vitamin C is an antioxidant that helps protect your cells against what are…