Thyroid UK
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Supplement advice

Hello again, 

I started 100mcg of levo for 3 weeks and was struggling with horrible side effects,  (dose to high for me to start off) gp reduced to 50mcg which I've been taking for 2 weeks now and feeling slightly more human again!

I've now introduced vit B12 methylcobalamin 1mg and 5- MTHF 1mg taking 2 hours after levo...2 days ago. For the first time I never slept last night, restless, hot and racing heart so got up and wondered about for a bit, felt a bit hyper. I've always slept well prior to taking levo and it takes me most of the morning to get through the haze and fog of this condition. When's the best time to take levo?

I don't know if introducing the vits has disrupted my sleep last night. I don't want to panic about it. 

I think the vits may help with my lethargy and give me the energy I've lost as well as digestion issues so would at least like to stick with it a bit longer (as long as im not doing myself more harm!)

Do you think the vits are causing this ( high dose too soon as with levo)?

Many Thanks

8 Replies


As the sleeplessness started 2 days after supplementing vitamins it would seem that one of them may be causing the problem.  I would stop the supplements for a week or two and then reintroduce one at a time two weeks apart.  You'll be able to determine which, if any, is the culprit that way.

Levothyroxine can be taken taken any time of day or night.  There is evidence demonstrating night time dosing is more effective at lowering TSH.


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.


Thankyou clutter,

Is 1mg of each an optimum amount to take?




It depends on what your B12 level is whether 1mg is sufficient.  I don't know what the 5-MTHF is for or how much is optimal.


My results 

B12  458  ng/L  150 - 900

Folate  11.4   ug/L  > 3.0

Graygoose recommended these to take, I'm just trying to clarify that I have bought the right dose.

Thanks so much



1mg methylcobalamin is fine.  I think your folate level is fine without supplementing.  A B complex vitamin would give folic acid a little boost and keep the other B vits balanced.


Greygoose actually recommended taking a B complex with methylfolate, so that you keep the Bs balanced. :) 


I echo what Clutter says, always introduce supplements one at a time, give time to see if it gives you any problems, if all OK then introduce the next one.

1 like

Many of us find taking Levo at bedtime gives better results 

But we are all different ....trial and error to see what works best for you

Either way it must be at least 2-3 hours after food and nothing but water for at least an hour after.


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