Thyroid UK

Should I reduce thyroid meds when B12 is optimal

I am currently taking 3 1/2 grains of Armour thyroid and have recently started B12 supplementation. My B12 result was 311 no range but fine according to GP.As I get the B12 up does it mean we need less NDT?Currently having blood tests every 6 weeks to check thyroid levels and have no symptoms of over stimulation. How often do we need to check B12 levels?

Thanks for your help.

7 Replies

Jjlily, B12 311 is within range but isn't optimal. B12 <500 can cause neurological damage so most of us supplement until B12 is at the top of the range. Supplement 1,000mcg methylcobalamin sublingual lozenges, spray or patches and take a B Complex vitamin to keep the other B vits balanced. You need to stop supplementing B12 for 4 months, the time it takes red blood cells to die off and renew, if you want a baseline test otherwise the result should be high when you are supplementing.

Good levels of B12 can improve your wellbeing but doesn't improve your thyroid function so continue on 3.5 grains Armour.

1 like

Thanks for reply Clutter.I had B12 tested before supplementing so 311 is a baseline.The only reason I had it tested was because I have numbness and tingling in feet and hands and headaches Problem is I had car accident and suffered spinal injuries and huge haematomas in both calves, so Gp thinks this is why I have tingling.

regards Jill


jjlilly, It'll take 6/8 weeks to raise your B12. If tingling improves you'll know B12 helped. Late 2013 I was vitD and folate deficient, had low B12 and was very unwell and struggling to tolerate thyroid meds. Correcting the vitamin deficiences and supplementing B12, B Complex, vitamin C, magnesium and zinc improved everything, including thyroid replacement absorption and conversion.


I have all the same as you Clutter. Doctor will not give injections B12 down to 247 ng/L (180.00-1130.00ng/L from 667 in May last year. Aches and pains got Vit D up from 29 to 85.5 doctors gave me supplements but has taken a year was taking Magnesium but run out and feel aches and pains again. Will buy zinc and magnesium again and B12 and B complex. I am following my gut instincts lost all faith in doctors. Also just dumped meloxacam nsaids as read about strokes etc, did not help and I cannot stand prescription pain killers although in pain and awaiting to see rheumatologist. Just want to be well again.


Unfortunately, your thyroid medication is for life and it's good you have no symptoms of overstimulation and if you feel well that's the correct dose. Don't let GP adjust your dose according to the TSH. It's how we feel that's the criteria.

Your B12 should be as Clutter suggested.

When you have a blood test for your thyroid gland, leave 24 hours between the last dose and the blood test. Take meds afterwards.

Sometimes a whiplash can start off hypothyroidism. I hope your tingling goes and has the hospital done an x-ray on your neck/spine.


Thanks for reply shaws I am pretty sure that being on NDT saved me from broken bones, as the policeman attending the accident was pretty sure I would have such was the impact and damage to vehicle.

I have had MRI of neck and spine and am now waiting for a brain scan. What annoys me is this is all costing the NHS and not the lorry driver that decided to use his phone.

It is surprising what illnesses can be caused by whiplash and head trauma.I was hypothyroid before the accident but pretty sure I now have Menieres.

Thanks again



NOT BASED ON BLOOD TESTS ALONE!! NEVER let your doctor mess with your medication unless he/she is willing to up the dose as well as lower it!! When it comes to dosing, in my view, the patient knows best, you know your symptoms and what happens if you reduce your dose so stick with it! TELL your doctor you will continue on your current regime for as long as you need to. Most doctors try and reduce your meds my endo did but I would not agree, they HAVE to have your agreement to change your dosage, simply do not agree and DO NOT stay silent as this is tacit to agreement.


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