Thyroid UK
82,761 members97,783 posts


Sorry too keep posting. So I'm pregnant and my b12 has been dropping very rapidly so I'm too supplement with some more b12 my pregnancy vits only contain 2.5mcg. My doc prescribed cyanococabalim 50 sorry if incorrectly spelt but from what I'm reading here that won't be enough. Side note I don't have pa so my body should absorb b12 from the gut.

Anyways so people here are suggesting 1000 daily b12 is that mcg or mg? Better you b12 spray is suitable for pregnancy but 1200mcg so does that then make it too much as I'd be daily taking 1200 plus the 2.5.

The really noticeable side effect is my left ear has started too ring again so I need too do something.

Many thanks again Annette

3 Replies

Hi nettiboo,

Yes it is confusing to begin with. You have had good replies here and if you would like to put apost up on PAS within HU, lots of members will help.

J 😊



You can take a 1,000mcg methylcobalamin sublingual lozenge or the Better You Boost 1,200mcg spray. B12 is water soluble so excess in the body is excreted in urine. You can't take too much or overdose.


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.



B12 is released for absorption by the activity of hydrochloric acid and protease, an enzyme in the stomach. Low levels of these are commonly found in those with Hashimoto’s leaving a risk for B12 deficiency. Also failing//suboptimal adrenal glands inhibits our ability to produce gastric acid.

Many hypothyroid people appear to have a polymorphism on their MTHFR gene meaning they can't use the common form of B12 so supplement methylcobalamin.

Methylcobalamin is less stable and needs greater amounts to achieve and maintain adequate Vit B12 levels. It is usually taken in amounts of 10-40 times as much ... hence large doses of 1000mcg a day are recommended.

You have been prescribed Cyanocobalamin by your GP and the usual recommendation would be between 25 -100 mcg. Therefore your dose of 50 mcg would be right but if you wished to supplement a more bioavailable form, Clutter has given you good info above.

Never be sorry for posting .... that's the point of the forum ... ;o))) ....


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