There is no doubt about it; the B vitamins are a confusing bunch. Each of them has a name and a number for recognition. Not only do we have two names to contend with but most have at least 2 or 3 different forms that have similar roles.
For example, Vitamin B6 comes in 3 forms: Pyridoxal, Pyridoxamine and Pyridoxine, which are all biologically active. Some B vitamins are known most commonly by their numbers, and some, such as Biotin (B7) and Folic acid (B9), are usually called by name. Then there are the gaps. We go from B3 to B5 to B7 to B9 and then skip to B12. Believe it or not there are logical reasons for the gaps that occurred while naming B vitamins [1].
A Bit Of History...
In the 19th century, the general theory of medicine said that illnesses were always caused by a variety of toxins entering the system. However, a series of experiments seemed to show that a deficiency of various nutrients might instead be the cause. The simple test for this is locating which set of foods had the ‘mystery nutrient’ and trying to isolate a solution that could be added to a control group's diet. By using this method Scientists found one substance that was fat-soluble and worked against a form of night blindness and a second water-soluble substance that worked against Beriberi Disease. They didn't yet know exactly what these substances were, so they coded them as Vitamin A and Vitamin B. Casimir Funk had conducted a series of experiments that showed one of these ‘nutrients’ had an amine group in it and so gave them the general name of ‘Vitamines’, ‘vita’ meaning life. Later, when they found some didn't have the amine group, they dropped the ‘-e’ to make it seem more general [2].
Why Are They So Special?
B Vitamins are different from most other vitamins because they are water soluble. This means they do not require fat to be absorbed and they are not stored by the body. However, they do need to be taken in regularly or health problems will develop. The only other water soluble vitamin is Vitamin C. However by then all the water soluble vitamins, with the exception of C, had been already grouped together into the B complex. There are gaps in the numbering because some of the compounds scientists once thought were essential nutrients were proven not to be, thus classified as non-essential. Remember, a vitamin cannot be produced by the human body, it needs to come from food or in the case of Vitamin D, from sunlight.
Filling In The Gaps
Vitamin B4 was first given the compound name Adenine, which was later found to be one of the nucleic acids that make up structural DNA. It can be synthesized by the human body and therefore not a vitamin.
Vitamin B8 is a nutrient that is known as Inositol. Even though it is often referred to as a vitamin, Inositol doesn’t meet the definition because it can be synthesized in the body.
Vitamin B10 is the name once given to Pteroylmonoglutamic acid, also known as Vitamin R. Scientists later decided this compound doesn’t provide the benefits that would classify it as an essential nutrient and it lost its vitamin status. Today you will often see Bara-amino benzoic acid or PABA called Vitamin B10. PABA is actually a component of Pteroylmonoglutamic acid and is also referred to as Vitamin Bx.
Vitamin B11 was the name given to Salicylic acid as well as Factor S. While this compound does play an important role in our health, it can be synthesized in the body and so it doesn’t fall under the definition of an essential vitamin. Pteryl-hepta-glutamic acid is also listed Vitamin B11, but it turns out this is actually a form of Folic acid (Vitamin B9).
Vitamin B13 is Orotic acid, it is sometimes used as a mineral carrier in some dietary supplements (to increase their bioavailability), most commonly for Lithium Orotate. But does not technically fit the definition of a Vitamin.
Vitamin B14 is thought to be a combination of Vitamin B10 and Vitamin B11. As of yet it has not been isolated as a specific substance. Currently, very little is known about Vitamin B14. It was isolated from wine, one theory suggest that it may be the metabolite of Xanthopterin.
Vitamin B15 is the Pangamic acid, also known as Pangamate. It is found in various forms,most popularly as a dietary supplement and drug, initially by Ernst T. Krebs and his son, as a medicinal compound for use in treatment of a wide range of diseases.
Vitamin B16 is the other name for Di-methyl-glycine (DMG), a derivative of the amino acid glycine and it is synthesized by the human body from Choline. It can be found in beans and liver, and unlike true B vitamins, deficiency of DMG in the diet does not lead to any ill-effects. Also, it can be synthesized by the human body in the Citric Acid (or Krebs) cycle meaning it does not meet the definition of a vitamin.
Vitamin B17 has been used for Nitrilosides, Amygdalin or Laetrile which are found in a number of seeds, sprouts, beans, tuberous vegetables and grains. It is thought to be toxic in large quantities, some make the bold claim that it is effective in treating cancer and act even acts as a prevention method despite a lack of scientific evidence [4,5].
- Vitamin B, Netfit Your Definitive Guide to Health and Fitness, UK
- www.boards.straightdope.com/sdmb/showthread.php?p=13464445
- Bender, David A. (2003). Nutritional biochemistry of the vitamins. Cambridge, U.K.: Cambridge University Press
- Bennett, David. All Vitamins and Pseudo-Vitamins
- B Vitamins. NeuroSoup (2013-04-15). Retrieved on 2015-11-30.