By Roberta H. Anding, MS, Baylor College of Medicine and Texas Children’s Hospital

Edited by Kate Findley and proofread by Angela Shoemaker, The Great Courses Daily

Vitamin C, also known as ascorbic acid, is one of the most popular supplements on the market today. Professor Anding explains how this vitamin earned its popularity status and he explores its many roles in the machinery of our bodies. 

History of Vitamin C

The popularity of Vitamin C is partly due to its connection with a Nobel Laureate, Dr. Linus Pauling. Dr. Pauling believed that vitamin C held many important roles, including treating the common cold and even chronic illnesses such as cancer when taken in high doses.

This association between vitamin C and disease prevention first came about when Dr. James Lind, a doctor in the British Royal Navy, conducted an experiment in 1747 with two groups of sailors at sea. One group was given lemon juice with their rations and the other group—a control group—wasn’t. 

This experiment showed that vitamin C in the form of lemon juice prevented scurvy, the vitamin C deficiency disease. Symptoms include degeneration of skin, teeth, and blood vessels and what are called “epithelial hemorrhages”—little pinpoint hemorrhages on your skin. 

Lind published his results in 1753, though the British Navy waited more than 40 years to add lemon juice or lime juice to the standard rations for British sailors. That’s where they got their nickname: “Limeys.”

Physiological Roles of Vitamin C

Physiologically, vitamin C is an electron donor for eight enzymes. That means it’s a chemical reducing agent or an antioxidant for both in-cell reactions, intracellular, and outside-the-cell, extracellular, reactions. 

As an enzyme cofactor, it allows that enzyme to do its job better. Vitamin C aids in the synthesis of carnitine, which is a compound that helps get fat through cell membranes. It is made from lysine and methionine, two essential amino acids. 

Vitamin C is also needed for the synthesis of collagen, which is a structural protein. Collagen is essential for wound healing. So, that’s where vitamin C gets its reputation as promoting wound healing.

Another use for vitamin C is in the synthesis of norepinephrine, which is a neural transmitter. It’s needed for peptide hormone synthesis, protein hormone production, and in the synthesis of tyrosine, an essential amino acid.

As a chemical reductant, vitamin C aids in the enhancement of iron absorption from the GI tract. Iron needs to be reduced in order to be absorbed; and thus if you want to increase the absorption of iron, you should take it with a source of vitamin C. For example, if you’re eating a roast beef sandwich, you can get more iron out of that roast beef by partnering it with an orange.

Vitamin Sources

As an antioxidant, in theory, vitamin C decreases the damage from free radicals and reduces some of the harmful reactions in the body. It helps to protect cell membranes against damage and maintains a significant role in producing cartilage, bone, and dentin, which is an integral part in the development of the tooth.

Primary sources of vitamin C are fruits and vegetables. For example, a quarter of a medium cantaloupe has 60 milligrams. 

Half a grapefruit has 40 milligrams, while half a cup of grapefruit juice has 35 milligrams. When it comes to vegetables, half a cup of cooked broccoli has 60 milligrams and a cup of canned sweet potato has 50 milligrams. In the American diet, the potato actually serves as a reliable and dependable source because Americans love potatoes, and we eat a lot of them.

This article was edited by Kate Findley, Writer for The Great Courses Daily, and proofread by Angela Shoemaker, Proofreader and Copy Editor for The Great Courses Daily.

Professor Roberta H. Anding is a registered dietitian and Director of Sports Nutrition and a clinical dietitian at Baylor College of Medicine and Texas Children’s Hospital. She also teaches and lectures in the Baylor College of Medicine’s Department of Pediatrics, Section of Adolescent Medicine and Sports Medicine, and in the Department of Kinesiology at Rice University.