Vitamin C.
Is it a vitamin? Is it Ascorbic Acid? Is it an essential nutrient? What exactly is it?
First, there are many different forms of vitamin C:
- Sodium Ascorbate
- Ascorbic Acid
- Magnesium Ascorbate
- Calcium Ascorbate
- Ascorbyl palmitate
Then, there are the metabolites of vitamin C:
- D-Isoascorbic
- DehydroAscorbate (DHA)
- Ascorbate radical
- Hydrogen Peroxide (H2O2)
Metabolites are the Rodney Dangerfield of physiology. Just look at hormone metabolites for evidence of that. But, the field of metabolomics and the 38,000 + estimated metabolites are changing all of that.
All are the different forms and the metabolites are members of the vitamin C and associated metabolite family. Beyond the name, and whatever the form is, it is the intended effect that is most important; so, what form and what metabolites that best help to achieve the intended effect is what should be the goal.
Vitamin C is called many things:
- Vitamin C (of course)
- Ascorbic acid
- Dehydroascorbate
- Electron donor
- Drug
- Pro-drug
- deliverer of H202
- Pharmaceutical Ascorbate.
It is all of these things and more. Patients, the general population as a whole, and the majority of the medical community know it as “vitamin C”. Whatever title is chosen to call it, I believe the biochemical effects and anticancer impact best identify “vitamin C” through its delivery of hydrogen peroxide (H202) and its function as an electron donor. More on this to come soon.
“The biological functions of vitamin C can be attributed to its biochemical property as an electron donor.” [1]
—Ngo B, Van Riper JM, Cantley LC, Yun J
Many would call it a Vitamin.
Words have their root origins in history. Sometimes in history, at the timing of word origin, a true understanding is lacking. But here, though not 100% exact, the origins of vitamin C did come really close to hitting the nail on the head.
Is it a VITAMIN?!?!
Vitamin was a word first coined by the Polish Biochemist Casimir Funk in 1912. It wasn’t vitamin as currently spelled, but vitamine from the two root words “vita-“ and “amines”. It was group thinking of the 19th century that all life required chemical groups called amines. Amines were thought to be vital to life. Amines sustained life. Without amines, life couldn’t exist. So, the theory went. The word life in Latin is “vita”. This led to the name “vital-amine” or “vita-amine”, or vitamin as it is commonly used today.
Is vitamin C a vital-amine?
Vitamin C is not a 19th century amine. Vitamin C structure is similar to that of glucose, but not identical. In fact, vitamin C is made from glucose by many plants and animals. But, humans do not make vitamin C because we have mutation in the coding of the gene guloolactone oxidase (GULO)—the gene that codes the enzyme guloolactone oxidase which converts glucose to vitamin C. As a result, humans can only obtain vitamin C through diet or supplementation. In this light, vitamin C is a nutrient that is essential to the human body nutrition. Because of a mutation in the GULO gene the gulonolactone oxidase enzyme, which is necessary and essential for vitamin C production, is absent [2].
Without the ability to make vitamin C, inadequate dietary vitamin C intake results in the disease called Scurvy. Never heard of it? Most have not. It is quite rare today and more a disease of the history books. The first historical reference of scurvy was all the way back in 1550 BC. Even Hippocrates, the father of western medicine, referenced scurvy; he called it “ileos ematitis” [3]. Fast forward in history to the 15th century, scurvy was the scourge of the seven seas. Scurvy was the leading cause of disability and death associated with long sea voyages. It was in 1747 that James Lind treated 12 sailors with six different treatments to prevent and treat scurvy. Only oranges and lemons were effective in the prevention and treatment of scurvy. Great example of critical thinking in history. It wasn’t until 1753 that the British Medical Journal recognized the connection of scurvy to a dietary deficiency. The years 1928 and 1933 advanced the knowledge of vitamin C and scurvy. In 1928, the scientist Albert Szent-Györgyi isolated a substance, that turned out to be vitamin C, from adrenal glands. He originally called this substance ‘hexuronic acid’. It wasn’t until 1933 that the scientist Charles Glen King isolated vitamin C and found it to be identical to Albert Szent-Györgyi‘s ‘hexuronic acid’ [4].
From 1550 BC to 1933 AD, scurvy is not just some historical reference. It easily was considered the #1 occupational mortality risk in the years 1500 AD to 1700 AD. An estimated 2 million sailors died secondary to scurvy. All at a time, when the world’s population was estimated at only 500 to 700 million.
To be clear, vitamin C is not an amine, but it is vital for human life. It is a vitamine. More important, it doesn’t matter what you call it, it only matter what its physiologic effect is. More on that to come.
[1] Ngo B, Van Riper JM, Cantley LC, Yun J. Targeting cancer vulnerabilities with high-dose vitamin C. Nat Rev Cancer. 2019 May;19(5):271-282. doi: 10.1038/s41568-019-0135-7.
[2] Fu J, Wu Z, Liu J, Wu T. Vitamin C: A stem cell promoter in cancer metastasis and immunotherapy. Biomed Pharmacother. 2020 Nov;131:110588. doi: 10.1016/j.biopha.2020.110588.
[3] Maxfield L, Crane JS. Vitamin C Deficiency. [Updated 2022 May 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK493187/
[4] Carpenter KJ. The discovery of vitamin C. Ann Nutr Metab. 2012;61(3):259-64. doi: 10.1159/000343121.
