Excess B12 possibly causing numbness and tingling

Posted by persistentc @persistentc, Mar 14, 2025

At a recent visit with my PCP, I asked her to run some labs. One of them, B12, came back at excessively high levels. This can cause numbness and tingling in your hands and feet! I had been told that you can never take too much B12 because anything your body doesn't need is excreted in the urine. But after doing a little searching on the internet I discovered that Methotrexate, which I take for auto-immune issues, can cause the body to retain the excess B12. I have just started infusions of Simponi to replace the use of Methotrexate. I will post again after I have been off the Methotrexate, which my rheumatologist says can't happen for a few months until the Simponi kicks in. However, I wanted others to be aware of this possible cause. As a note, the PN did not start until AFTER I began taking Methotrexate, so I am pretty hopeful this may lead to some relief in a few months!

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Profile picture for seekingsanders1957 @seekingsanders1957

I also started experiencing numbness & tingling in my arms & legs about a month ago. I had a B12 test taken and it came back 1535 which is significantly elevated. I was initially advised to take a B12 supplement because I am vegan. I was basically told that it was probably neuropathy after seeing a doctor. I am diabetic but my blood sugars levels have always been controlled. I think it's the elevated B12 levels, but my question is how long it will take for my B12 levels to fall back within normal ranges (days, weeks or months)? I stopped taking the B12 supplement two weeks ago, but I am still experiencing the tingling & numbness. I would appreciate any insights regarding this dilemma.

Sincerely John Sanders

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I stopped the B12 back in March. My levels were taken again last week, and they were still quite high, not at toxic levels, but WAY above the normal range. The reading I have done since then suggests it may take YEARS for the B12 to be excreted.

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Hello, I appreciate the reply to my inquiry and your information. Oh, my I was hoping it would not take years, but I will take another B12 test in 3 months to check my levels. Thanks

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Profile picture for jankavs @jankavs

I had b12 level at 2000 when I went to hospital for my symptoms that got so bad that I thought I might have had a stroke (before any diagnosis). I was told to just stop it altogether for awhile, but not told when to resume. I am vegan, so I resumed supplementation at a much lower dose about 3 months later. I now take 500 mg about 4 days per week.

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Did you mean mcg? 500 mg would be a LOT!

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Profile picture for persistentc @persistentc

Did you mean mcg? 500 mg would be a LOT!

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Yes! 500 mcg of methylcobalamin.

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Profile picture for seekingsanders1957 @seekingsanders1957

Hello, I appreciate the reply to my inquiry and your information. Oh, my I was hoping it would not take years, but I will take another B12 test in 3 months to check my levels. Thanks

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Please let us know how it turns out!

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Profile picture for persistentc @persistentc

Please let us know how it turns out!

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I absolutely will, best regards

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Profile picture for persistentc @persistentc

I stopped the B12 back in March. My levels were taken again last week, and they were still quite high, not at toxic levels, but WAY above the normal range. The reading I have done since then suggests it may take YEARS for the B12 to be excreted.

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Hello, can you provide some references materials that you read regarding the time frame for B12 being excreted.

Sincerely John S

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Here's an update on my post from almost 18 months ago ...

I stopped taking the B12 and eventually got my levels down, but it took a LONG time to get there.

I was then put on Simponi Aria to treat Axial Spondyloarthritis.

After 4 infusions, I tried getting off methotrexate and failed, due to excessive pain in my hands as well as a trigger finger on my left ring finger which was so painful it woke me up at night. Copper compression gloves help some, but they are not a cure. But it did not help the AS, and it did nothing for the PN.

I tried getting off Hydroxychloroquine. Pretty much the same thing happened. (Both hydroxychloroquine and methotrexate are implicated in PN.)

Switched to Cimzia. Still having pain in hands as well as everything else that goes along with PN. Tremor in right hand got much worse, such that I could not even write on some days.

Now I have moved on to Cosentyx. Too early to tell. It's a different class of drugs, so who knows. My second infusion is next week.

In the meantime, I finally caved and had the EMG done. They did the study on my right side. He did identify a pinched nerve in my right elbow (a surprise because this may be the one area of my body that was NOT bothering me), and LFN.

Went back to the neurologist ready to start treatment. She said, "Well, there's nothing we can do." I just looked at her with incredulity and said "So why did you tell me you couldn't treat me for PN until I got the EMG? She referred me to her boss, Dr. Rebecca Traub, who is the doctor I was trying to get to see originally because she is listed on the PN site. That appointment is next week. I want to be optimistic, but ...

To complicate the picture, I have been having terrible pain in my neck on the left and I did convince the first neurologist to order an MRI. It showed multilevel degenerative changes with moderate canal narrowing at C6-C7 and severe neuroforaminal narrowing on the left C3-C4, bilaterally at C4-C5, and on the left at C6-C7. I have already had 2 fusions (2000, 2006) so this is not good news. I have an appointment with the UNC Spine Center on September 1.

I'm feeling very frustrated. My balance is off, my legs feel incredibly heavy. It has become difficult to keep up with doing laps at the pool 3 times a week because my legs get tired. The ring and pinky fingers in my right hand have gone numb (which makes it incredibly difficult to put out all my medication for a week into my pillbox). And of course, there is the numbness and tingling in my feet and calves. BMI is 20.1 so it's not as if I am overweight.

I am only 70. My parents lived into their mid-90's, so I should have many years ahead of me yet. Am I doomed to live with this condition for another 20+ years?

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