Urine vs blood for B vitamins - anyone understand why one could be high and one low?

[jsy_girl]

I have had several blood tests for Vitamin B12 which has increased over the past 12-14 months via supplementation (igennus super B mainly). My latest medichecks result was:

31March active B12 204 pmol/L (25.1-165)

I then had a Dutch test which involves both saliva and urine tests. As part of the urine testing they test B12 and B6 markers which it says may be deficient if high. Both were high suggesting deficiency.

Methylmalonate (MMA) Above range, 2.7 ug/mg (0-2.5) (Vitamin B12 marker)

Xanthurenate Above range, 2.82 ug/mg (0.12-1.2) (Vitamin B6 marker)

Kynurenate Above range, 7.1 ug/mg (0.8-4.5) (Vitamin B6 marker)

So after this I decided to get a vitamin B6 blood test from medichecks as I didnt want to supplement B6 if it was also high, and like B12, it was high:

7June B6 29.7 (8.7-27.2) over range

My functional doctor suggested this is a result of insulin resistance, and working on insulin resistance will help. I know insulin resistance relates to sugar but does it also work with letting vitamins in? I have PCOS which is why i have some insulin resistance. I also have no thyroid and am on levothyroxine and liothyronine in case that is relevant.

My B12 was low before I started supplementing, but it would seem potentially i'm not actually absorbing it properly. Just wondering now what to do about supplementing? Is it pointless if its not actually going in?

Has anyone come across this before?

[Gambit62 Administrator]

Do you have a diagnosis of type 2 diabetes - the main mechanism for type-2 is insulin resistance?Not sure how insulin resistance would relate to B12 absorption problems, unless you are on metformin. B12 is used in the process that cells use to release energy and deficiency has been a rare cause of ketoacidosis - something that is more commonly associated with diabetes. I can't comment on any links between B6 and insulin resistance.

MMA is usually significantly raised in patients who are B12 deficiency - whereas the result you have is marginal. MMA can also be raised due to kidney problems - which is why a urine test is advantageous - but it can also be done as a blood test.

Your B12 test was an active test and the results indicate that you are probably supplementing more than you need. There is no need to take high dose unless you have an absorption problem.

I would suggest that you look into the qualifications of your functional doctor just to ensure that they are a fully qualified medical doctor - there is quite of a lot of outdated information about B12 that still seems to be circulating around functional medicine

[jsy_girl in reply to Gambit62]

I don’t have type 2 Diabetes or any kind of diabetes. I have PCOS, and the root cause of that is insulin resistance. So I am on a low carb diet and take certain supplements to basically increase my insulin sensitivity. I believe if I let it go unchecked it may eventually lead to Diabetes.

I don’t really understand the link to B12, I understand the mechanism behind insulin resistance but that’s why I was asking here. And further I don’t understand why my blood levels would be slightly over range but my urine test suggest I’m deficient. Clearly supplementing more won’t help. What does a urine test deficiency suggest when a blood test would suggest supplementing wouldn’t help?

My functional doctor is not medically qualified she has a functional medicine qualification via chris kesser and I’m find about that but she was suggesting I supplement B6 which I wasn’t comfortable to do when I knew my B12 gave these opposite readings, hence I also did a B6 blood test and got same conflicting result.

[Gambit62 Administrator in reply to jsy_girl]

According to this article - and at least one other I have looked at the exact cause of PCOS isn't clear and it is only that it may be related to insulin resistance not that it is related to insulin resistancehopkinsmedicine.org/health/...

There is also a higher probability of going on to develop type 2 diabetes if you have PCOS.

As above, your MMA isn't raised enough to indicate that you are B12 deficient.

It sounds as if your functional doctor is part of the cohort that are still acting on some outdated information about the way B12 works.

I would strongly recommend that you try to see a medically qualified doctor and work with them on how to treat your PCOS.

I believe there are other forums on here that deal with PCOS and it may be that you are more likely to find the answers you are looking for on those forums.

This forum came up when I did a search on PCOS

healthunlocked.com/verity-pcos

[jsy_girl in reply to Gambit62]

Hmm medically trained doctors are typically absolutely rubbish at treating PCOS. They generally know less than the patients. Verity is okay. I have my PCOS generally very well under control by managing insulin resistance. There are other causes but this seems to be mine. It was really this specific angle around B12 urine test vs blood test that I was interested in. If the urine test looks okay then I’ll ignore it and only start supplementing again when my active B12 looks like it needs it.

[Gambit62 Administrator in reply to jsy_girl]

That is what I would suggest