The high vitamin D content in cocoa and dark chocolate helps strengthen your immune system, especially during the darker months of the year. Dark chocolate also contains theobromine, which wakes you up and doesn't cause the subsequent fatigue crash that other sweets do. The pure cocoa powder also contains magnesium, making it perfect for sore muscles. Dark chocolate also contains a lot of tryptophan, which puts you in a good mood, helps with stress, and gives you plenty of energy. It's also good for beautiful skin, which is another great bonus.