Vitamin C is an essential nutrient that prevents scurvy, a disease characterized by bleeding gums and bruising. It was discovered in the 17th century that lemon juice prevented scurvy in sailors. Vitamin C is found in many fruits and vegetables and plays an important role in immune function, collagen production, iron absorption and cardiovascular health. A daily intake of 60 mg is recommended, though some research suggests higher intakes may provide additional health benefits. Without enough vitamin C, scurvy will develop due to a breakdown of connective tissues.