I have just been looking at the documentation (SPC and PIL) for a number of Folic Acid products. It appears they contain the following words – or similar:
4.4 Special warnings and precautions for use
Folic acid should not be administered for treatment of pernicious anaemia or undiagnosed megaloblastic anaemia without sufficient amounts of cyanocobalamin (vitamin B12) as folic acid alone will not prevent and may precipitate development of subacute combined degeneration of the spinal cord. Therefore a full clinical diagnosis should be made before initiating treatment.
I can't for the life of me understand why the specific reference to cyanocobalamin is there. Especially given standard PA treatment is hydroxocobalamin injections.
Any sensible ideas?
Written by
helvella
To view profiles and participate in discussions please or .
I was prescribed folic acid long before my low B12 result then I came across this.........
Before you start taking folic acid, your GP will check your vitamin B12 levels to make sure they're normal. This is because folic acid treatment can sometimes improve your symptoms so much that it masks an underlying vitamin B12 deficiency.
Maybe it was the prescribing of folic acid as to why my low B12 was missed and my neurological symptoms still persist even though I now inject B12 daily !
It is almost at the level of trivial to follow that advice about checking B12. (If it weren't the phlebotomy but just, say, a urine dipstick test, it would be totally trivial.)
I've certainly lost count of the number of times I have pointed out not to start folate/folic acid before checking B12 over on Thyroid UK forum.
It was my heamatologist (top lead in London ) who put me on the folic acid ! When a couple of years later I explained to her my B12 was lowand I had been started on B12 injections her reply was she new nothing of B12 deficiency. That was *loody obvious. 🤬
I told my MP that 'he was like a car salesman' he was good with the sales technique but he didn't have a clue what went on under the bonnet. His reply was he found me very offensive.
My heamo is apparently just a poor anticoagulist ! Aw, poor love.
My neurologist was so pleased that I was on a regime of B12 injections he wrote to my GP saying so. The problem with that was the GP had told me I was poisoning myself 🤣😂🤣
Even if cyanocobalamin were the only form available, it's not as if the lab measures cyano- in your blood and ignores hydroxo-!
And if it is a convention of some sort, about time it got changed. Anyone reading that who hadn't been expressly inducted into the interpretation of that "special convention" would get misled or confused. Or both.
I don't have a ready answer either. Now you have me curious and i will fall into a rabbit hole of checking all the folic acid leaflets from every country 😆
The Dutch Teva 5mg f.a. only talks about "untreated b12 deficiency" as a contraindication without mentioning treatment.
The Belgian Folavit 4mg f.a. is similar & talks about untreated b12d and PA, and goes on to mention risk of nerve damage if "B12" is not given, and that they should be treated together. Type of b12 not specified.
The Turkish Folbiol 5mg is very similar to the belgian one. They refer to "B12" or the generic "cobalamin".
All 3 countries mainly use Cyano though hydroxy is available.
Will have to check the German ones tomorrow from my computer.
Maybe this is a UK specific thing??? Which would make it even stranger!
Confusing, isn't it? I suspect the chance use of 'Cyano' instead of 'Hydrox' etc is a simple slip of the fingers, and it might have been better to simply say 'Cobalamin'. But the important thing is it's alluding to the well-known risk of treatment with folate when the B12 level is low. Start off with low B12, take folate, use up the remaining bit of B12 you had left and end up in a wheelchair, or words to that effect.
An aside: When it came to measuring B12 in the laboratory 'in the old days' by microbiological assay, the first part of the process involved separating the B12 from the binding proteins, in an acid buffer in an autoclave, and converting it all to cyanocobalamin, using potassium cyanide. Making up that buffer, with cyanide, always gave me the shivers!
The Old Days? Well, we were using the Lactobacillus Leichmanii assay in 1968 when I started. We were experimenting with radioisotopic assays at that time too, but they required a reliable source of Intrinsic Factor as a binder, so it was a nightmare. Then, commercial assays came in certainly by the 1970s, using isotopes, and we were able to assay B12 and folate in a single step [Simultrac] which made life simpler, although whilst we could understand what went on in the microbiological assay [still in use in some places] we were getting further and further from the science and more into automated systems. The later assays are non-isotopic and very, very slick! However, there are several manufacturers, making different kits, which all work very reliable but they're all different, which is why it's best to stick to one lab for your samples if you want to follow the results.
I had a temporary job as a hospital cleaner in early 1970s. Used to do the path labs - and what a nightmare! So many things to avoid touching by accident. Plastic tubes and pumps everywhere.
At a guess, this is US-sourced material, even if supplied with UK-packaged medicines, where cyanocobalamin is the usual form? But yes, they really ought to add e.g., and even better reference hydroxycobalamin for Europe.
standard in the UK is hydroxocobalamin but in many countries it is cyanocobalamin. If the article was written by researchers in the US then it's likely they are only aware of cyanocobalamin - seems to be a blindness there to the fact that there are other forms.
But it wasn't! This is UK documentation approved by the MHRA.
Obviously, it could be quoting something originally written by anyone, anywhere. But it looks like the sort of thing that should be picked up by each company, and by the MHRA, as they documents are produced and approved.
I’ve been on Cyanocobalamin for over 40 years for my pernicious anaemia and haven’t had any problems apart from one doctor stopping it for several years cause he said I didn’t need it anymore 😡. Hope this helps. Take care
Helps me Hedgehog! Thank you for this - I inject with cyanocobalamin because of the cost and ease of acquiring it & it was what I received at my doctor's office.
But I only have one kidney, sometimes that sits in the back of my mind. So boy do I appreciate that your post came from helvella's pamphlet curiosity.
I have lots of other work to do, so of course I'm now procrastinating looking this up .
The NHS itself talks about who cannot take it "have low vitamin B12 levels (vitamin B12 deficiency anaemia) or pernicious anaemia" nhs.uk/medicines/folic-acid...
Now I'm curious, in which folic acid product(s) have you actually read the "treat with cyanocobalamin" phrase?
------
German folic acid - at least Folsan 5mg - only mentions not treating in the presence of B12 deficiency, megaloblastic anemia, and to find the cause first.
The NIH fact page at least mentions the risk of supplementing folate when B12 is low and/or there's megaloblastic anemia. ods.od.nih.gov/factsheets/F... This paragraph has references to papers discussing this risk. Handy to show the doctor when they prescribe high doses of folate without treating B12D!
Large amounts of folate can correct the megaloblastic anemia, but not the neurological damage, that can result from vitamin B12 deficiency. Some experts have therefore been concerned that high intakes of folate supplements might “mask” vitamin B12 deficiency until its neurological consequences become irreversible. Questions about this possibility still remain, but the focus of concern has shifted to the potential for large amounts of folate to precipitate or exacerbate the anemia and cognitive symptoms associated with vitamin B12 deficiency [2,85,148-153].
Folic acid should not be administered for treatment of pernicious anaemia or undiagnosed megaloblastic anaemia without sufficient amounts of cyanocobalamin (vitamin B12) as folic acid alone will not prevent and may precipitate development of subacute combined degeneration of the spinal cord. Therefore a full clinical diagnosis should be made before initiating treatment.
What is considered a large amount of folate? My folate was 24 and my B12 was 252 when I asked to be tested for deficiency. I have neurological symptoms such as pulsatile tinnitus, tingling in legs and feet. Other symptoms include digestive issues, breathlessness, heart rate spikes. Because I have no evidence of anemia, and my level is still in the normal range, I’m having difficulty convincing doctors that I have a deficiency. I am not vegan or vegetarian, am on no meds that would cause my level to be that low, and do not have any other underlying health issues. Iron and thyroid are normal. Only other level that was below range was my white blood cell count. So I am wondering if my folate is masking my B12 deficiency….
Any amount of folate could potentially mask deficiency but i think they normally refer to doses of 1000mcg and higher. The 'masking' they refer to is a normalization of homocysteine and enlarged blood cells (high MCV).
But up to 20-30% of people with b12 deficiency & neurological symptoms never develop abnormal red blood cells.
I suggest you copy/paste your question into a new post , it will be easier for all to follow. I or someone else will add more info about appropriate testing and treatment. Your levels sound low. Please also add the ranges for your results, because they vary from lab to lab.
Thank you for your reply. I was not supplementing with folate at the time of testing, which I thought was odd that it was that high. I believe anything below 200 is considered B12 deficiency as I’m in the US. I have been given injections (12 since January) but not frequent enough to keep symptoms at bay. I have been through 3 doctors so far, with the 3rd being a hematologist that I had to beg for four more weekly injections before he put me on monthly (even though I’m still having some symptoms). I have a follow up with him next month so I would like to go into that appointment armed with info. I am also reading Could it be B12.
I do urge you to create a brand new post to discuss your specific issues.
And it is important to state the units in which B12 (and other) tests are measured. Not everywhere uses the same units. Nor are reference intervals (ranges) the same between labs, let alone across continents.
Not abnormal at all, if there's not enough circulating B12, the folate will just sit around waiting. The two go hand-in-hand.
It is difficult to get proper treatment, as many of us know.
Please do start a new post. You will get many more replies and useful info to arm you for your appointment. Right now, your question is hidden in a post with 41 replies, and no one will see it (or only the very few interested in the intricacies of folic acid leaflets, LOL).
Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.
Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.
)
Cyanocobalamin Tablets
Hydroxocobalamin and Cyanocobalamin 
CYANOCOBALAMIN injection?
Cyanocobalamin & Methylcobalamin Injections
