Scientific Advances in and Clinical Approaches to Small-Fiber Polyneuropathy (2019) Oaklander et al

A review of small-fiber polyneuropathy. Interestingly, it says that evidence suggests it contributes to PEM.

https://jamanetwork.com/journals/jamaneurology/article-abstract/2749401

 

This bit in the paper seems an important warning, as there is a lot of advice on ME/CFS out there that suggests supplementing with B-vitamins - high levels of B6 are bad for SFN!

Full paper can be accessed here
https://sci-hub.se/https://jamanetwork.com/journals/jamaneurology/article-abstract/2749401

 

Do you know what a high B6 level would be?

I didn't see a specific bench mark noted in the NIH articles below; of course this would depend on age, gender, size etc.


About B6 from Medline Plus - NIH - U.S. National Library of Medicine: https://medlineplus.gov/druginfo/natural/934.html#Dosage

"What dose is used?
The following doses have been studied in scientific research:

ADULTS

BY MOUTH

......

• For vitamin B6 deficiency: In most adults, the typical dose is 2.5-25 mg daily for three weeks then 1.5-2.5 mg per day thereafter. In women taking birth control pills, the dose is 25-30 mg per day....."

There are several health conditions listed, and recommended doses for each.

Odd, I can't find the RDA in this article, except for as noted above for deficiency.

Another NIH article has the RDA for various stages of life:

https://ods.od.nih.gov/factsheets/VitaminB6-Consumer/

 

According to LabCorp this is the reference range for normal levels
Male: 5.3-46.7 µg/L; female: 2.0-32.8 µg/L
https://www.labcorp.com/test-menu/36686/vitamin-bsub6-sub-plasma

Even a small amount of supplementation every other day took my blood levels above the high level which would be bad for small fiber neuropathy. I wish I had never taken it - At the time I was left with the impression that vitamins were harmless and any excess would not be absorbed by the body.

 

@wigglethemouse

Thank you. I've seen B6 in a 250 mg strength, as just a run of the mill supplement. This level is certainly over the RDA.

 

I used to take this - Natures Bounty B Complex from Amazon. Vitamin B6 content 5mg, 294% % daily value. I used to take half a pill every other day and that was too much based on blood testing.

 

I have supplemented with B6 on and off because it’s recommended for minimising menstrual issues. I also have taken half tablets due to the dose of all the contents being so high it seems ridiculous.