Vitamin B-12 Level High While Taking Supplements

by Laurie
(Virginia)

My fathers B-12 was low back in Seotember 2015 and his caretaker started supplementing 5000 mcg daily. The doctors never did a follow up until I requested one, which was drawn 3 days ago (1-18-16).

The result was 1862 - way over the normal range of 211 -911. In reading about the possible side effects of too much B-12, I found a side effect listed that stood apart from the rest, which had to do with increasing certain cancers... specifically Prostate Cancer, which he has!!!

My question to you is.... what dosage is a safe dosage and for how long? I do not want his B-12 to get low again because he gets depressed and he also has mild Dementia. At the same time, I don't want it to get so high that it could be exascerbating the Prostate Cancer, which at 89 years old he has decided not to treat.

Please advise.

Comments for Vitamin B-12 Level High While Taking Supplements

Click here to add your own comments

Ignore the blood test.
by: Kerri Knox, RN, The Immune Queen

You cannot get an accurate blood test while on Vitamin B12 supplements. There is no risk of cancer from high B12 levels from SUPPLEMENTS. The risk comes from having high levels when you are NOT taking supplements.

This is because a high level when NOT taking supplements indicates the MTHFR Gene.

Don't worry about his high level. He was low. He needed Vitamin B12. There is no known toxicity with B12 supplements, just be sure that he's taking Methylcobalamin B12 for his neurologic health.

Vitamin B-12 Level High While Taking Supplements
by: PJ

If a person has symptoms of b12 deficiency while taking supplements, should she stop supplements before getting an MMA test? If so, how long before the test should supplements be stopped?

MMA test is worthless on supplements
by: Kerri Knox, RN, The Immune Queen

The MMA test is worthless while you are on supplements. Don't waste your time and health care dollars.

How long to wait after you are off supplements before doing an MMA test? I have no idea, but would suspect that it would be several months in order for it to be accurate.

Even then, the MMA test is not particularly accurate and can give false negatives. The BEST test is simply to take B12 and see if it makes you feel better, or resolves your symptoms.

B12 dosage
by: Anonymous

My B12 level was 217 and I had some physical symptoms, so I started taking 1000mcg/day of sublingual methylcobolomin, after about 80 days it was about 390. My doctor asked me to increase the dosage to 2500. After 90 days of increased dosage the result simply says >1200, well above normal.
So whats the next step ?. Stop the medication , wait 10 days and re-test?

[Kerri's note: High levels of B12 when taking Vitamin B12 are normal and are not a reason to stop taking it if you are feeling well and wish to continue taking it. You could drop the dosage back to the original dosage if you wish]

Sublingual 5000mcg methylcobalamin B12
by: Anonymous

I was taking B12 sublingual 5000mcg methylcobalamin almost everyday for 2 months! My level was already in 600 range but I learned this after starting this routine! I thought it would give me energy! When I had physical it was 1824! Way over range! All my other blood work was fine! Would too much supplementation cause this? Disturbed me after reading online about cancer etc....

High b12 without supplements
by: Kerri Knox, The Immune System Queen

High B12 when you are taking supplements is meaningless. If your B12 levels were low PRIOR to taking supplements, then it's highly unlikely you have the MTHFR Gene Mutation.

Click here to add your own comments

Return to Vitamin B12.

Enjoy this page? Please pay it forward. Here's how...

Would you prefer to share this page with others by linking to it?

Click on the HTML link code below.
Copy and paste it, adding a note of your own, into your blog, a Web page, forums, a blog comment, your Facebook account, or anywhere that someone would find this page valuable.

Search this Site

Custom Search

Free Vitamin D Fact Sheet by Getting
My Newsletter