B12 & B Complex confusion: Hello I am a member... - Thyroid UK

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B12 & B Complex confusion



I am a member of both the PA group & Thyroid UK (I have Hashimotos)

3 months ago my B12 was 295 (211-911).

Following advice from members from both groups I was advised to supplement with 5000mcg B12 for a few months alongside a B Complex, then reduce to 1000mcg as a maintenance dose for the rest of my life, again with a B Complex supplement too. The suggested brands of B Complex were Jarrows & Thorn Basic B.

My confusion lies with whether of not the B Complex' suggested are actually too strong, many , if not all of the RDAs are way over 100%. In some conversations, folk have been refered to the NHS page for Vitamin guidance, I have seen suggestions of getting Tesco's own B Complex where RDAs are 100% (which contains B12, but I'm not sure in which form) and I continue to see the ones I was told about recommended.

I just want to improve & maintain my B12 levels and try to ensure that I can protect myself as much as possible against any neurological damage. I'm convinced that my B12 supplementing has helped with my pain, brain fog, tripping on words, etc (although this seems to have returned since I stopped supplementing for the IF test, which came back as 2 (0-24), I assume that is good news.

My B12 was tested again and the result this time was 830 (211-911), although I realise supplementing will have skewed that result. My Ferritin levels had improved to a perfect level following 4 weeks of supplementing, latest Folate result has got lost but was 9.49 (>5.38) 3 months ago so I am hoping my B Complex would have improved that too.

My plan was to reduce to 1000mcg B12 and carry on with a B Complex, but I need to know which B Complex to aim for. Also, if the B Complex also has B12 in, I was hoping for the Methly' version., so any suggestions there would be helpful.

If anyone can 'unconfuse' me, I would be hugely grateful....Thank you.

I have also posted this in the PA group ☺

10 Replies

Complex topic. Lots to know.

First, everyone has different needs for B vitamins based on genetic differences and environmental factors. The RDAs or DVs are set to avoid beriberi, pellagra, etc. for the population at large and have very little to do with your health. You likely need much more than 100%.

I have some interesting genetics and my body has been under multiple stresses, and my body is sucking up large quantities of Bs. I take 1,000 to 100,000% of the DV of most Bs. Irs not right for everyone but it's what I need now.

My doctor monitors my status through these tests:



Methylmalonic acid (MMA)

RBC folate




Best of all is a Genova Diagnostics NutrEval, which is most comprehensive, though it takes 3-4 weeks for results.

A word of caution - to much or too little folate can be bad. Very bad. Best to know how much you need. And what type you do best with. Many people don't do well with folic acid, which can build up to toxic levels in some people. Most people do well with a form called 5-methyltetrahydrofolate, or 5-MTHF.

For many people I know, it's best to start up the B12, or methionine cycle, by adding B!2 til your levels are good. 8-900 is fine, you can go higher, too, on a standard test. The MMA is far more accurate for determining your need.

Then, if you're short of folate, add it. I find when I get enough B12, it starts pulling folate out of the folate cycle and I start to become depressed, which is how Know whether I need more folate. Once the depression goes, I back off on the folate.

You also need B2, B6, and B1 as cofactors for the folate and B12 cycles. This whole process is called methylation and it's essential in every cell in your body, helping you properly copy DNA, detoxify heavy metals, etc. The other Bs are helpful, too.

So, if you haven't done all the tests I mentioned, what should you do? Taking the 1mg of methyl B12 to keep your level around 800-1000 is a good idea, as well as the Thorne Basic B or Stress B. Or there's Thorne B complex #12 which emphasizes more B12 for those who need it. Thorne is very trustworthy and uses the most bioavailable forms of Bs, not the cheaper, less useful versions. They have the Bs in good ratios to keep the cycles going... you don't want too little if one ingredient so everything comes to a screeching halt. Taking some magnesium citrate, glycinate, or malate is a good idea, too.

Having your homocysteine around 6-8 and your MCV below 93 would be good values to watch. The tests are relatively easy to get. I do the NutrEval once a year, and its been an essential tool at figuring out what's going on.

And, if you feel anxious or depressed, it's likely something isn't balanced correctly. Time to do some testing or experiment to find out what works better.

Good luck, I hope this helps you.

in reply to Learner1

Thanks for a sensible and comprehensive post.

in reply to Hidden

You are quite welcome!

in reply to Learner1

Thank you Gambit62 and @Learner1 .... for your detailed replies. In the Thorns Basic B Complex that I have been taking, the B6 is10mg (500%) DV, which in the US and the EU would then not be seen as a possible cause for concern, whereas here in the UK, it would be seen as hugely overdoing it if their reccommendations are 12.5mcg.

The Folate in the Thorns is L5 Methly' (100%DV), the Tesco version is Folic acid (100% RDA)

See why I am so confused???😂

This is where I am at the moment (mentally & physically)

I feel my thyroid medication has finally kicked in and is at the right dose. I feel that my B12 supps are having a positive impact on my body and mind. I have cut out gluten, I have looked at my diet and nutrition and have made huge efforts to get rid of the rubbish. I am sleeping better, have always had plenty of exercise, fresh air, etc.

My biggest issue, always has been, is being a worrier, stressing about everything and anything. These 2 forums (PA & TUK) have been a lifeline in my recovery this year ......ABSOLUTELY NO THANKS TO MY GP! My last remaining goal is to de-stress and that's the reason for this post.

I feel good at the mo' (fingers/toes crossed) and I planned to just slink away and get on with living life, which I haven't done for the last year. I thought I was doing the right thing with my B12 supps, B Complex and Thyroid meds, until replies in other folks posts said diferently from what I had read and been advised myself.

I understand that we are all different....therein lies the problem I guess.

So am I still confused? Yes. ☺

in reply to janey1234

Sounds like you're on the right track - keep up the good work!

You might look into mindfulness if you haven't already - it would fit in well with the changes you've shared.

As for the Bs, I understand the confusion. 😉

I'd stay away from folic acid or anything fortified with it and focus on eating dark leafy greens and taking 5-MTHF.

As for B6, there are reports of toxicity at 200mg. However, I developed sideroblastic anemia, where the body is so deficient in B6 it can't properly make hemoglobin in red blood cells, on 180mg and so have been taking 300mg for the past year. I ran out a few months back and forgot to replace it immediately and couldn't sleep well until I went back on it. So 12.5 mg is pretty ridiculous in this context.

So, I encourage you to find the amounts that are right for your body, especially if you have anxiety, depression, fatigue, or brain fog, which are telling you you haven't found the right balance.

Good luck!

in reply to Learner1

Thank you Learner1 .

I think I will stick with the Thorn Basic B which has 10mg of B6 & 400mcg Folate (100% DV)... Decision made 🤗

I was actually talking to my daughter about Mindfulness the other day, so will definitely look into that further.

Now....I must saddle up, ride off into the sunset and get my life back on track.

I wish you well and thank you again xx

sorry ..my post won't really help you... I got confused when I read that your IF result came back as 2. I got a print out of my results and it just says Normal. Why is '2' good news? I am sorry I don't know much about IF. Thanks!

in reply to VickyB12

Hi VickyB12 ... whilst googling I found an earlier post on this forum where somebody asked much the same question about their IF bloodtest result meaning. Their result was 6 or 7 in the same range as my print out of (0-24) and apparently that was a 'normal' result, higher or over 24 would have meant otherwise. So that's why assumed my result was normal too ☺

in reply to janey1234

Thank you... I am confused because I don't have a figure..just saying Normal..but you know sometimes very low or very high is not really 'normal'! x

in reply to VickyB12

Perhaps it depends on the lab or your GP as to how the results are given.

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