Thyroid UK
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B12 recovery - how long?

When I had a full blood count done in about November my B12 was 284 (190-900) and my gp grudgingly gave me 50mcg cyanocobalamin. I tried this for a while (about a month) and then, after posting on here and taking note of replies, I bought some 5000mcg Jarrow and Solgar. I've been taking one a day now for about 6 weeks.

My question is this - how long before I start to feel the benefit? I did feel a little better after about 3 weeks but I seem to have dipped down again. Any help most welcome :)

6 Replies


I would expect improvement in some symptoms 6-8 weeks after taking 5,000mcg assuming, of course, that the symptoms you are experiencing were due to low B12.


I am not a medical professional and this information is not intended to be a substitute for medical guidance from your own doctor. Please check with your personal physician before applying any of these suggestions.

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How would I know? The gp doesn't seem interested in investigating further - surprise surprise!


Do you know your level of folate? Folate and B12 work together in some way that I've never understood, and I know it isn't a good idea to supplement one without the other.

Also, I've read that people shouldn't supplement one B vitamin exclusively, they should supplement all of them.

You would get good advice if you joined the HU forum for the Pernicious Anaemia Society.


When I had the full blood count my folate was 9.6 ng/mL (4.60-20) which is 'in normal range' but I can see is not even half way. I think I understand from what I've read on here, that it's better near the top of the range? 

I'm taking a B complex with the B12 but it's a Holland & Barrett one. When they're all gone I'll order the type usually recommended on here, although I can't remember just now what they are! Memory loss!!

Is it ok to take 2 x B complex at the same time or should they be at different times of day? Does it matter?


The B Complex usually suggested is any one which contains as many B vitamins as possible in a format which is easily absorbed. So, that means methylcobalamin instead of cyanocobalamin, methylfolate instead of folic acid, and a few others that I can never remember. The one I use is Thorne Research Basic B Complex which I buy from Amazon. There are others that are good - Pure Encapsulations has some good products I remember.

I prefer my folate to be in the upper half of the range, and preferably in the top quarter of the range, but I don't want it to go over. I've had an over-the-top result in testing folate once (from Blue Horizon Medicals) and the doctor's report said something like "this is well-tolerated and isn't a problem", but I still want it to be in range.

Methylcobalamin is not poisonous and going over the range isn't an issue :

I wondered why you took 2 B Complex capsules? Deficiency of vitamin B6 should be avoided, but so should toxicity :

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I'm taking 2 because that's what it says on the jar!

However, as they are H&B ones they are, of course, cyanocobalamin and folic acid.

When they're all gone I'll get the Thorne :)


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