Advice on Vit D and Vit b12 dosage


I posted a couple of days ago regarding lastest TSH result at 4.3 (taking 75mg levo) Vit D level 22 Vit B12 377

G.P. perscribed Natecal D3 (Calcium + Cholecalciferol 600mg/400i.u. twice daily) but as they upset my stomach I purchase my own and now take Vit D 1000i.u daily but Moggie said I should be taking a much higher dose and my G.P. should have ordered a High power dose from the hospital. Does any one know what dose of Vit D I should be taking, also Moggie suggested I take B12 as it should be nearer 700. again what dose should I be taking, I am going to make an appt. with G.P. this week to discuss high TSH but want to go armed with as much info as possible


27 Replies

Minimum 2000-5000 IU daily. 1000 IU daily will only maintain your current level.

Many thanks for your reply

any idea on how much B12 I should take


Your Vit D level is very low, I wouldn't take anything less than 5000 IU/day personally. My Vit D level was 37 and i'm taking +10000 IU/day (safe) to build up my levels to the optimal 50-70 ng/ml. In a few months I'll retest to see how I stand. If i'm in the optimal zone then i'd consider taking only 5000 IU/day, anything less than that and i'll be back to being deficient. Sorry no idea about B12.

Many thanks for your reply, I will order some now

Are you feeling better with taking it?

Not yet, I've only just started, it takes months for levels to rise, so watch this space.

You can buy 10,000 iu from Amazon



Your levels were very similar to mine and I take 9000 iu VitD3 busing a sublingual spray and 3000 mcg B12 sublingual nuggets. The B12 is very expensive and I will try the spray after this as I have read here that that is very good as well. I have also read that taking it sublingual spray is almost as effective as having injections. I have been taking this for about 6 weeks and thought I will ask for a retest in a couple of mts


Thanks for your reply

Do you feel any better since taking both?

I did to start with but seem to have dipped again, dont know the reason. I take so many supplements now it is difficult to know what works and what doesnt. I am trying to get to as near optimal levels in preparation of seeing Dr Skinner and hopefully get NDT or at least T3.


Thanks again

Hope you feel better once you have seen Dr. Skinner

If I don't improve I shall also look into seeing him

Let me know how you get on

Good Luck

...take a look at and on the Homepage there is a graph showing your VitD blood result and what is needed as a dose to bring it up to a good level. For every 10 units under 70 you will need a 1000 IU's per day. Graph in top Right Hand Corner. Site looks old fashioned - Canadian and full of valuable information....

B12 - take a 1000mcg x 2. Sublingual is good or a spray. Result needs to be around 800 I believe. You can't overdose as it is water soluble.....


I have looked at grassroots, very interesting

Will be buying supplements now

Thanks again

If you supplement Vitamin B12 it has to be methylcobalamin (that is very important). I find Amazon good for supplements and there is a variety of prices. You cannot overdose on B12 as is excess excreted in urine.

I take 2x 20,000 iu tablets a week. Prescribed by my GP and dispensed by my local pharmacy. My vit D level was 11 it is now 70 after 8 weeks.

Is there any reason you're taking 2 x 20,000 IU/week as opposed to 4 x 10,000 IU/week or even 7 x 5000 IU/week since they all total to equivalent levels of around 40,000 IU? I'm guessing megadosing helps with absorbtion if 2 x 20,000 IU/week is preferred.

Two reasons, my GP said that larger less frequent doses were more effective at raising blood levels. I also suffered indigestion when taking a daily dose so I tolerated this better

Thanks, I imagined this to be the case.

Thanks for the info

Thanks for your reply, did you ask your doctor for this dose or did he just perscribe it

as mine only perscribed 800 i.u. daily and my level is 22

I obviously need more. Do you feel alot better now your level has risen

Hi Browny, no, he gave me a lower dose to take daily first but it didn't shift my level at all. He then just gave me the dose above. I did overhear in my pharmacy last week though that GPs might be restricted in prescribing vit D soon, it was a pharmacist talking to a colleague. Not sure what this means in practice but sounds like a cost cutting measure to me. I still have an 8 week supply left. I can't say I feel better as I was diagnosed with Hashimoto's 5 weeks ago and the same GP gives almost homeopathic doses of Levothyroxine!

Hi Marie

Do you mind me asking what thyroid levels are, mine are TSH 4.3

T4 13 I am taking 75mg levothyroxine at bedtime, the replies I have received on this site say TSH should be alot lower, below 1.0 to feel well

but I was wondering if once Vit D levels go up do the thyroid levels improve

My blood results are a bit out of date as they predate being put on Levo, they are due again in 3 weeks. (tSH 2.9, T4 14) It is difficult for me to say if thyroid levels have improved as Vit D improved because I was diagnosed with Hashi in the middle of that process. Hope it does for you though. Try to get out in the sun for 30 mins in the middle of the day ( complete opposite to normal sun safety advice) sun exposure is still the most effective way of raising Vit D. That's if you can find any sun!

My D level was as low as yours and I tried taking the 5000 i.u. gels of D3 all summer while getting a good tan. This only raised me two points. I think when your hypothyroidism is undertreated as yours seems to be, you just don't absorb well or convert the sunshine well, either. I ended up, as you also might, taking the high dose prescription. This brought my levels up to 37 after 3 months, which is still almost deficient. I may have to do another round.

Thanks Heloise

What dose are you on now

This is interesting. Last year I felt like I was cutting a wisdom tooth but I'm way past the age for that. The doctor said it just looked like bone on the x-ray. I wondered why I would be growing bone in my jaw. On another website someone said they had this same problem when taking D3. I have no proof that this is possible but I would say to watch out for it.

Since my over the counter D3 did not seem to work, I bought a 5,000 i.u. D3 sublingual with K2 but it is not an oil product like I thought it should be so I'm hesitant to take it. I then bought a liquid D3 with K2 thinking I might be able to absorb it better. Each 5 drops is 2,000 i.u. Truthfully, I'm in a quandary about it but it is such a vital hormone that I am anxious to raise my level. After I test again to see if any of these later attempts work, I will probably get the high dose prescription.

Yes, I think you are right Heloise, hypothyroidism and low Vit D seem to go hand in hand. Mine did raise quicker, but I'm going to keep a close eye on them, especially as my GP seems to be phobic of prescribing Levo!

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