1. Vitamin C

Vitamin C plays an important role in keeping us healthy. Most mammals produce it in their livers, so they never suffer from a lack of it. Curiously, however, some mammals, such as humans and apes, cannot do so. What happens when you lack this important vitamin? You might see blue-and-black marks on your skin.Your teeth could suffer too: the pink area around them become soft and bleed easily. There are just a couple of good reasons to eat plenty of fresh fruit.