Unraveling the Mystery of Vitamin B20
In the alphabet soup of vitamins, some letters and numbers are conspicuously absent from the officially recognized list. The concept of a "vitamin B20" is one such case, a term that exists more in marketing and historical context than in modern nutritional science. The truth is that there is no officially recognized vitamin B20. Instead, the name was historically applied to a substance now known as carnitine, a compound the human body can produce endogenously. This reclassification happened as scientists learned more about which nutrients were truly essential for human survival and could not be manufactured internally.
The Story of Carnitine
Carnitine, often referred to as L-carnitine, is a compound synthesized in the body from the amino acids lysine and methionine. Because the body can produce it, it does not meet the criteria of an essential nutrient that must be obtained solely through diet. Its primary function is to transport fatty acids into the mitochondria, where they are burned for energy. This crucial role in energy metabolism is why it became associated with the B-complex vitamins, which are famous for their role in converting food into energy. While it is important for human health, the ability of the body to make its own supply means it no longer occupies a spot on the official list of vitamins.
A Look at Other 'Lost' B-Vitamins
Carnitine is not the only compound that once held an official-sounding B-vitamin name. Throughout nutritional history, several substances were classified as B vitamins before being reclassified or discarded as non-essential. Understanding these "lost" vitamins helps to clarify why the numbering system isn't sequential from B1 to B12.
- Vitamin B4 (Adenine): A nucleobase found in DNA and RNA, it was once thought to be a vitamin but was later determined not to be essential.
- Vitamin B8 (Inositol): A form of glucose that helps the liver process fats and supports cell function. The body produces its own supply, so it is no longer considered a vitamin.
- Vitamin B10 (PABA): Para-aminobenzoic acid was identified as a nutrient for microorganisms but is not considered a vitamin for humans.
- Vitamin B11 (Salicylic Acid): Another compound removed from the official list, involved in tissue formation and metabolism.
- Vitamin B13 (Orotic Acid): Involved in the synthesis of nucleic acids, but produced by the human body.
- Vitamin B15 (Pangamic Acid): Found in apricot seeds, this was promoted as a cure for many ailments but is considered unsafe and ineffective by modern science.
- Vitamin B16 (Dimethylglycine, DMG): Acts as an antioxidant and is sold as a dietary supplement, but is not a vitamin.
- Vitamin B17 (Laetrile): A controversial and toxic substance found in fruit pits, wrongly promoted as a cancer cure. It is not a vitamin and should be avoided.
- Vitamin B18 (Choline): Essential for many bodily functions, but since the liver can produce it, it is classified as a nutrient but not a vitamin.
Established B Vitamins vs. 'Lost' B Vitamins
The following table compares the currently recognized B vitamins with some of the historically misclassified compounds, including carnitine (vitamin B20).
| Attribute | Recognized B Vitamins | Historically Misclassified 'Lost' B Vitamins |
|---|---|---|
| Essential Status | Must be obtained through diet as the body cannot produce enough. | Often produced by the human body or found to be non-essential. |
| Numbering | Follows a specific sequence: B1, B2, B3, B5, B6, B7, B9, B12. | Numbers are scattered and non-sequential (B4, B8, B13, B20, etc.). |
| Examples | B1 (Thiamin), B2 (Riboflavin), B9 (Folate). | B4 (Adenine), B8 (Inositol), B20 (Carnitine). |
| Metabolic Role | Act as crucial coenzymes for energy production and cell metabolism. | Roles vary, and some claims lack scientific backing. |
| Safety & Regulation | Regulated with established Recommended Dietary Allowances (RDAs). | Safety and efficacy can be questionable, especially with unregulated supplements. |
The Dangers of Marketing Misinformation
Some supplement manufacturers continue to use outdated or misleading terminology like "vitamin B20" to market their products. This can cause confusion and lead consumers to believe they are purchasing a different or more potent nutrient than they are. Supplements labeled this way typically contain carnitine. The best practice is to rely on the advice of healthcare professionals and evidence-based nutrition information rather than marketing buzzwords. Reputable supplements will list the compound carnitine by its proper name, not an obsolete vitamin designation.
The Final Word on Vitamin B20
In summary, the term vitamin B20 is a piece of nutritional history, not a component of modern scientific classification. The nutrient it once referred to, carnitine, is a valuable compound for energy production, but since the body produces it, it is not an essential vitamin. The best way to approach your health and nutrition is to focus on the eight officially recognized B vitamins and other essential nutrients, guided by a balanced diet and professional advice. For more information on the official B vitamins, consult authoritative sources like the NIH [ods.od.nih.gov].
