Is it normal for B12 to drop quickly?

[Hashi-Monster]

I have not been diagnosed with PA but was tested for B12 in January and it was quite high 2304ng/l, I attributed this to injection b12 therapy I had the year before. So my doctor asked me to stop all B supplements. I have just had it retested and it has significantly dropped in less than 3 month to 476ng/l

Is this rate of reduction normal?

I’m already diagnosed with Coeliac and Hashimoto

[Gambit62 Administrator]

B12 levels are likely to drop pretty quickly until they get to the level that you really need once you stop supplementation - as the amount you were using to supplement was presumably 1000mcg+.

How do you actually feel - are you symptomatic of B12 deficiency?

The level you quote is a level at which most people would feel and would be perfectly fine. Having hashimotos and coeliacs does mean there is a good chance that you will have absorption problems but that is very different from saying that you definitely do have absorption problems.

[Hashi-Monster in reply to Gambit62]

Thanks for the response, your explanation makes senses

I feel fine no different from when my levels were high

I was just surprised how quickly it dropped as I know B12 can be stored in the liver for years

[Gambit62 Administrator in reply to Hashi-Monster]

yes, but if it is stored in the liver it isn't in your blood ... and the role of the store in your liver is to regulate the amount in your blood when it gets low. The liver only has a finite capacity so if you supplement more than you need the excess stays in your blood until your kidneys remove most of it and you use a little of it ... until it gets down again to the level where you need it. If you start putting B12 into your blood faster than your kidneys remove it then the levels build up - like running the taps into a bath with the plug out - you can still fill the bath if the taps are turned on enough.

[Hashi-Monster in reply to Gambit62]

Great explanation ... makes sense

Is there any down side to having elevated levels ? E.g stress on kidneys ?

[Gambit62 Administrator in reply to Hashi-Monster]

no known toxicity from B12.

Not sure what the consequences would be if you have significant kidney disease but not aware of anything that points to it being an issue.

[Hashi-Monster in reply to Gambit62]

Thanks Gambit62 very helpful 👍