Vitamin C refers to a water-soluble vitamin that is found in citrus and other vegetables and fruits. It is helpful in treating and preventing scurvy. Vitamin C is an essential nutrient required for the enzymatic production of some neurotransmitters, repairing tissues and in the production of collagen. It is also essential for the functioning of numerous enzymes, and plays a significant role in immune system function. Vitamin C also works as a type of antioxidant. Several animals are capable of synthesizing their own vitamin C. However, monkeys and apes including humans, some rodents, most bats, and some other animals must obtain it from nutritional sources. There are several diseases which can be caused due to lack of vitamin C such as cardiovascular diseases, COVID-19, iron deficiency and several infections. This book provides comprehensive insights on the effects and mechanisms of action of Vitamin C in human health and disease. It will prove to be immensely beneficial to students and researchers engaged in the researches on this vitamin.