Pernicious Anaemia Society
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Homocysteine meaning ?

Hello everyone so extremely happy to find this intelligent site, so impressed, beyond❤️

I have a question about homocysteine result a nuerologist PA just gave now, she said it was low , 18, is that bad? She said she didn't know

I'm in the hospital and am being ignored re B12 issues. I'm a vegan 7 years

I sublingual B12 methyl high doses esp lately since Becoming ill a month ago thinking I have absorbsion problems

I had asked for mma also when I got to hospital 2 weeks ago she just said they didn't do it and just walked away..

I'm still confused can't look up things easily

Would greatly appreciate any info if I need b12 injections while here

B12 level was 1100 last week as I was mega dosing before I got here and she said folate was normal today, had to keep asking every day for these other tests and hense have folate and homocysteine today.

Thank you from the bottom of my heart for any advise❤️

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Hi Carae I'm not medically trained but perhaps the following "snippet" might help.

"B12 has two main jobs in the cell - one of them uses up a chemical called methylmalonic acid (MMA) the other uses up homocysteine (hCys). If the B12 isn't getting from the blood to the right places in the cell then one, or both, of these chemicals will not be used up and the amounts in the cell (and in the blood) will increase.

So a blood test for MMA and/or hCys can tell if the B12 is doing what it's supposed to be doing. If the levels of the two chemicals are normal then B12 is working properly. If the levels are raised then one explanation is that B12 isn't working properly (there are other possibilities - MMA can increase because of kidney disease, hCys can increase if folate is low).

But the key is that if either MMA or hCys is low then you know that B12 is definitely getting into the cell".

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Thank you so much I couldn't have figured that out am Very Ill

So it's not B12 not vegan related

Many many thanks

Thank you so much for your help


Your B12 level is high, which is good; and your hCys level is low, which is also good. It really looks like, if you did have a low B12 problem, the sublingual methylcobalamin is doing what it is supposed to do.

If you had been low for a long time then it may take a while for the treatment to work fully.

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Thank you so much for your replies They are so v clear and helpful forward ❤️


The above latest BMJ research document might help convince your clinicians to do further tests.

Very best wishes for good treatment and a speedy recovery Carae

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Thank you



I always understood that levels of homocysteine above 15 were high ? 🤔

"Most laboratories report normal homocysteine levels in the blood between 4 and 15 micromoles/liter (µmol/L). Any measurement above 15 is considered high. Optimal homocysteine levels are below 10 to 12.22 "

What are high homocysteine levels? - eMedicineHealth › page4_em


Thank you so much I will verify figure she gave me hopefully tomorrow


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