The Type of Vitamin B6 That Causes Vitamin B6 Deficiency
Vitamin B6 is incredibly important to health and commonly taken as a dietary supplement. Recent research shows taking the wrong form is likely to result in a functional Vitamin B6 deficiency.
Vitamin B6 is a cofactor for many other compounds that play integral roles in our bodies. Screw something up with your B6 levels and it’s likely to have a very negative cascade of effects throughout your body.
Recently, I came across a study that showed a certain form of the vitamin — pyridoxine — might actually cause symptoms of Vitamin B6 deficiency. It seemed strange to me and I thought it was worth digging into.
Real Quickly: Types of Vitamin B6
Vitamin B6 is the umbrella term given to a family of compounds including pyridoxal, pyridoxine, pyridoxal, pyridoxamine, and pyridoxal 5`-phosphate (P5P, PLP). This means that Vitamin B6 supplements might contain any of these forms. As it turns out — some types of Vitamin B6 might do more harm than good.
The Pyridoxine Paradox
In their paper, The Vitamin B6 Paradox: Supplementation with high concentrations of pyridoxine leads to decreased b6 function, researchers demonstrated a common form of B6 found in supplements can ultimately result in a functional B6 deficiency. Crazy, right?
This research was inspired by several case studies where supplementation with >50mg of pyridoxine resulted in symptoms associated with B6 deficiency. Researchers’ in vitro study found that pyridoxine, when taken in high amounts, blocks the ability to convert to the active pyridoxal 5`-phosphate form (P5P).
The P5P form is what the body ultimately ends up using whereas other forms much go through a conversion process. It always seemed sensible to me to take a supplement as close to the final functional compound as possible — to conserve energy metabolism if nothing else.
Researchers ultimately concluded as follows:
Perhaps it might be better to replace pyridoxine by pyridoxal or pyridoxal-phosphate as vitamin B6 supplements, which are much less toxic. In this way, the vitamin B6 paradox may potentially be prevented.
Why You Should Care About Vitamin B6
The importance of specific nutrients can be hard to express. There’s consideration to be made for deficient, sub-optimal, optimal, and excessive amounts. There’s also consideration to be made for direct and indirect metabolic impact.
Vitamin B6 is a cofactor for over 160 enzymes — each of which determines how other compounds are handled and/or utilized (R). Its influence within the body is very much a cascading effect. Screw up your Vitamin B6 status and any number of other things can go haywire.
I recommend checking out the ExPASy cofactor listing for B6 to get a better idea. There you can find a listing of the compounds that require B6 (P5P specifically) and links for more information on each.
This article was adapted from a longer article I wrote on the subject. It’s got some deeper discussion on the types of B6 out there, what to look for in a Vitamin B6 supplement, as well as some nutritional considerations from a Ph.D. in nutritional science. Here’s a link: