Evidence against naturally high active B12?

[Sunnysidoop]

I'm hoping you guys can help please. Does anyone know of any credible sources, that'd stand up to doctor scrutiny, that describe how high active B12 can highlight a problem? I.e. that the b12 is stuck in the blood and can't get into the cells. Our 6 year old has out of range high active B12. We're seeing a paediatric about a bunch of immune type symptoms... Recurring cold sores, mouth ulcers, nose and ear skin infections, nausea. Thanks so much

[Technoid]

The normal place to look is Homocysteine and MMA testing but there have been cases of B12 deficiency with neurological symptoms but normal B12, MMA and Homocysteine.

"in the seventh year of the study period, one patient with total absence of vibratory sensation in the iliac crest, knees, and ankles had complete recovery following 2 months of Cbl therapy despite normal Cbl, MMA, and HCys levels. Thereafter, therapy was offered to all patients with hematologic or neurologic abnormalities consistent with Cbl deficiency regardless of the results of screening studies.

ashpublications.org/blood/a...

Unfortunately there is no gold standard test for B12 deficiency and patient symptomology must take precedent, something most doctors are sadly unaware of.

[Technoid]

B12 levels can also be false high as a result of serious underlying health conditions. This would be an elevation in the absence of supplementation or injections, as injections or supplementation would also raise blood value. I am not medically trained so please do not jump to any conclusions on that and be aware some details in the following paper may be upsetting.

academic.oup.com/qjmed/arti...

[Sunnysidoop in reply to Technoid]

Fascinating read, thank you

[jade_s]

Two more papers that might help you are:

Sensory Neuronopathy Revealing Severe Vitamin B12 Deficiency in a Patient with Anorexia Nervosa: An Often-Forgotten Reversible Cause ncbi.nlm.nih.gov/pmc/articl... Discusses Functional B12 deficiency. The patient presented with neurological symptoms suggestive of B12 deficiency, but serum levels were normal. Treatment with B12 injections eliminated almost all of the patient's neurological symptoms. It also talks about high B12 levels being misleading.

Macro-B12 masking B12 deficiency ncbi.nlm.nih.gov/pmc/articl... Discusses Functional B12 deficiency due to "macro-B12": when B12 is bound to an immunoglobulins, rendering it unusable to the body. The macro-B12 molecule is picked up by the standard serum B12 test, making it appear as if one's B12 levels are normal. Treatment with B12 injections eliminated almost all of the patient's neurological symptoms.

It's also known that high levels of intrinsic factor can interfere with a serum B12 test but I'm not sure how that affects active B12.

[jade_s]

You might also find this website useful

b12deficiency.info/children/

And may want to consider inborn errors of cobalamin metabolism. While most children are symptomatic at birth, some children are only diagnosed later b12deficiency.info/wp-conte... - these are older papers. Here is a newer one but it's behind a paywall. Let me know if you would like a copy.

David Watkins, David S. Rosenblatt , Chapter Thirteen - Inherited defects of cobalamin metabolism, Vitamins and Hormones, Volume 119, 2022, Pages 355-376 sciencedirect.com/science/a...

[deniseinmilden]

Terribly sorry for you and her. Good luck.