B Vitamins – An Important Overview

This article (and the rest in this series) are meant to provide a solid foundation in your understanding of the B vitamins. For such an important class of vitamins, there is far too much ignorance surrounding the topic. These will help answer a lot of important questions and clear up a lot of misunderstandings. Feel free to share these on social media and re-post them on forums. They will help a lot of people make more informed choices with vitamin supplementation, specifically the B vitamins.

What are B Vitamins and why are they named this way?

Before delving into what exactly B vitamins are, let’s back up a bit and provide a larger framework and some relevant historical context.

Vitamins in general are defined as:

“Any of a group of organic compounds that are essential for normal growth and nutrition and are required in small quantities in the diet because they cannot be synthesized by the body.”

As you can see, this is a pretty general definition, and it leaves a lot of room for interpretation. It could be argued that a lot of substances could be classified as a “vitamin” according to this definition. It is anything but cut and dry.
The seemingly organised naming system of Vitamin A, Vitamin B, Vitamin C… and the subgroups (B1, B2, B3…) make all vitamins appear to be well named and organised clearly into some special class of compounds. But they are not. The naming is surprisingly arbitrary for all vitamins.
The names of each vitamin is based more on history of discovery rather than on some logical naming system. Scientists in the past named a certain set of organic compounds “Vitamin A”, and then a different set “Vitamin B”, a different one “Vitamin C” etc. The system is very arbitrary.
So the “B vitamins” simply refer to a particular group of compounds which play an important role in cell metabolism.
You may wonder if there is any specific reason that the vitamin A compounds are called “A” and the vitamin B compounds are called “B”. The answer is no. It could have been the other way around.

You may also wonder, why do we have vitamin A, B, C, D, E, and K, but you never hear about vitamin F. What is going on there? It seems only logical to use every letter right?

Well, in fact they did try to use every letter. Originally, vitamin F was reserved for Omega 3 and Omega 6 fatty acids. But the names “Omega 3” and “Omega 6” became the popular names rather than “vitamin F”.
This was because scientists later discovered that these omega 3 and 6 fatty acids were not really “vitamins” according to their loose definition, so they just dropped the idea of calling them “vitamin F”. So the name “Vitamin F” will always be vacant.
This is similar to the other missing letters. “Vitamin G”, originally riboflaven, for example, was re-named “Vitamin B2” because scientists figured it’s function was more in line with the other B vitamins.

There are in fact many different B vitamins. You will hear about vitamin B1, B2, B6, B12…

So what are these B vitamins and why do they have different numbers?

What ties the B vitamins together is their basic function on the human body. The B vitamins are water soluble, and they each play a basic role in cell metabolism. They each help facilitate many important and complex processes in the body, but more detail on that below…
Each different B vitamin is a totally separate substance however. Eg. B3 and B12 are totally different from each other. They are not at all the same substance. They just play somewhat similar roles in the body.
Vitamin B1 is a substance called Thiamine for example. Vitamin B2 (formarly known as vitamin G) is a substance called Riboflaven. Thiamine and riboflaven are 2 totally different substances and just arbitrarily named B1 and B2.
So in many ways, it would have made more sense to study Thiamine on it’s own and Riboflaven on it’s own without giving them special extra names.
When you name both of these substances “B vitamins” with a different number associated, it makes people assume they are more connected to each other than they really are in actuality.

And just like the “missing vitamins” like “F”, “G”, “H”, …, you’ll also likely notice that you won’t see many of the B numbers. You’ll hear about B1, B2, B3, and B5. But you won’t hear about vitamin B4 for example.
That is because vitamin B4 was originally reserved for the substance “adenine”, but adenine was later found out to be synthesized in the body. And substances which are made in the body are not vitamins by definition. So the name “B4” was dropped. We now just call “adenine”, well, “adenine”.
There are similar reasons for all the other “missing B’s”. Each number was originally designated to specific compounds, but later found to be inappropriate for various reasons to hold the title as a “B vitamin”. That is why you won’t see “vitamin B8” for example, but you will see “vitamin B9”.

Now that we’ve adressed this messy, albeit interesting, vitamin naming system. Let’s go ahead and discover what the different B vitamins are, what they do, and why we need them.