Vit B12 and folic acid

[Louise9999]

Hi everyone

My names Amy, i wasnt sure what community to post this is as i havent been diagnosed with pernicious anemia but was today told i had lower than normal B12, folic acid and vitiam d which was very low. Anyhow i have been perscribed folic acid tablets and B12 tablets, i was reading my folic acid tablets and it says dont take if you have B12 Deficiency. I don’t understand?

Thank you

[Galixie]

The reason the tablets have that warning is because both folate deficiency and B12 deficiency can cause macrocytic anemia. B12 deficiency can also cause some additional symptoms/problems that folate deficiency doesn't cause. Taking folic acid tablets can correct macrocytic anemia but it won't address any of the other problems that a B12 deficiency can cause, and those problems shouldn't be ignored. So if you take the folic acid and your doctor sees that your blood tests look normal (no macrocytic anemia) they might not realize that damage is still occurring due to the B12 deficiency.

That being said, your doctor is already aware that you are deficient in both B12 and folate, so it should be ok to take the tablets *on the condition that your doctor has already determined the cause of your B12 deficiency* (which they probably haven't).

If you have an absorption problem, then B12 tablets will not help you and taking both folate and B12 at the same time might make it difficult to determine if the B12 tablets are really helping or not. You might want to question your doctor about exactly what they've diagnosed. Unless you are vegan, it is unlikely that you lack B12 in your diet, so there might be an absorption problem that is going undiagnosed.

[Gambit62 Administrator in reply to Galixie]

Actually I think the warning is more to do with the very small risk of precipitating neurological damage if you take folic acid whilst B12 deficient - however the risk is very small and is more a matter of making sure that you have got your B12 levels up before taking the folic acid. The processes that lead to anaemia are not involved in this instance.

[Galixie in reply to Gambit62]

This is what I was referring to: ncbi.nlm.nih.gov/pubmed/145...

Specifically this:

"There is a risk that if folic acid is given to people who have undiagnosed deficiency of vitamin B12 it may lead to neurological damage. Vitamin B12 deficiency produces both an anaemia identical to that of folate deficiency but also causes irreversible damage to the central and peripheral nervous systems. Folic acid will correct the anaemia of vitamin B12 deficiency and so delay diagnosis but will not prevent progression to neurological damage."

[Gambit62 Administrator in reply to Galixie]

Thanks Galixie - there are also a few reported cases where it is suspected that administering folic acid to a patient who was B12 deficient actually lead to a step change in neurological problems.

Whilst there haven't been any specific studies in humans there have been studies in fruit bats showing that administering large doses of folic acid in the presence of a B12 deficiency causes spinal chord problems.

[Louise9999 in reply to Galixie]

Thank you. No the cause hasnt be determined and i was just told told to take the tablets and have a repeat blood test im 3 months

[spacey1 in reply to Louise9999]

Repeat bloods might be helpful for your folic acid levels, but if you take supplements, your B12 will likely show up as through the roof, even if your body isn't able to access any of it to use. That could be an issue if you really need injections because you're not absorbing what you need - it would look like you had plenty when you really didn't.

[Louise9999 in reply to spacey1]

Thank you for all your information I requested my test results and my b12 was 182 folate 2.4

[Gambit62 Administrator]

if you have both folate and B12 deficiencies that suggests that you have an absorption problem which means that tablets are unlikely to be effective in treating the B12 deficiency. Even if they are very high (1000mcg +) they are going to be a very slow way of getting your B12 levels back up again.

Where are you based Louise? If in the UK then please go back to your GP and ask them to take a look at the BCSH guidelines on diagnosis and treatment of cobalamin and folate disorders which they can access through the BNF but can also be accessed here

onlinelibrary.wiley.com/doi...

key things to draw to their attention are

a) that folate and B12 deficiency together suggests and absorption problem

b) B12 absorption problems should be treated with injections - loading dose and then maintenance - with different regimes if you have neurological symptoms

c) B12 deficiency should be corrected first - and then start the folate 24-48 hours after your first B12 shot.

[Louise9999]

Thanks everyone called the doc and he said to take them. Doesnt need further tests to check if i cant asorb b12 although i highly doubt its diet releated as i eat a lot of foods containing B12