How do I know if I have functional b6 or b12 deficiency?

[ModernLifeIsWar]

I recently had bloodwork as I suspected possible b vitamin deficiencies among other things due to symptoms I've been experiencing. Unfortunately I started supplementation with several vitamins including high doses of b12 for about a month or so prior to getting bloodwork, stopping the b12 about 2 weeks before and the rest about 1 week (in attempt to get as accurate of blood levels as possible).

However much to my expectation my b12 was still elevated. The scale only went to 1200 which I maxed out. My mma was <.10 and homocysteine was 6.7 on a scale of 3.7-13.9. Folic Acid was 21.7. Does this rule out any chance of a functional b12 deficiency?

Also, as mentioned I had not supped b6 in a week or more before my bloodwork. I was only using a combined total of 70 mg a day (50 synthetic before I knew better and 20 from p5p). However, my BW was still elevated at 134 on a scale of 20-125. I'm wondering if a functional b6 deficiency is possible as well. I read elsewhere that it is very rare to have elevated b6 levels using under 100 mg a day and I had only been using this dose for a little over a month and none for about a week prior to my bloodwork.

Any thoughts on this? Right now I'm only taking 5 mg a day p5p in half a dose of the Thornes Multivitamin I got. However, I'm wondering if I shouldn't be taking more if there is a functional deficiency, yet at the same time am worried about worsening a potential overdose of b6 if there is not and my levels are simply too high.

 

[Critterina]

To know if you have functional deficiency, you need to know if, for the chemical reactions that are facilitated by these enzymes/vitamins, the reactants or the products of these reactions are piling up or in short supply. That would mean an amino acid panel. I like serum aa panels, since that is what my practitioner ordered. Then interpreting it, it's best to have professional on board.

 

[alicec]

My mma was <.10

I don't know what the reference range is but from the way the result is reported I take it this is a lowish result. If so you don't have a functional B12 deficiency. Elevated MMA (in either blood or urine) is a very specific marker for B12 deficiency.

High blood levels of vitamins sometimes indicate increased intake but can also mean poor uptake into cells. Other tests are needed to determine functional deficiencies.

Serum B12 is a very unreliable measure of anything other than frank deficiency.

There is some literature indicating that very high levels of B6 in blood are associated with neurotoxicity but the issue is not clear cut.

An OAT test can be very useful in determining B6 deficiency - several markers, including elevated kynurenic acid.

 

[Critterina]

Every lab report has a reference range - it always helps when people post their lab results if they post the reference range with it!

 

[Critterina]

There is some literature indicating that very high levels of B6 in blood are associated with neurotoxicity but the issue is not clear cut..

Yes, so true. What's so frustrating is that deficiency and toxicity have some of the same symptoms. (Which is also the same symptom as I was told was a nerve being pinched between two joints in the ball of my foot! At least I don't have to worry about it being deficient/toxic or the onset of inherited non-diabetic peripheral neuropathy anymore.) The other thing that's variable is that one person was toxic at only 100 mg/day, but most people tolerate quite a higher dosage - not that you'd know what's safe for YOU and what's not, which is why 100 mg/day is considered the highest safe dose.