Folate & Potassium - ADMIN NOTE: do n... - Pernicious Anaemi...

Pernicious Anaemia Society

32,627 members23,989 posts

Folate & Potassium - ADMIN NOTE: do not take large doses of Potassium unless under medical supervision

rachelabc profile image
11 Replies

There are two things I wanted to start a discussion on with regards to B12 dosing: folate and potassium. I'll start with potassium, because I think it's more important.

Many people on this board rightly advise newcomers to monitor potassium levels when beginning B12 supplementation. However, in my medical textbook under B12 supplementation the following warning is given:

"Hypokalemia and sudden death have occurred in severe megaloblastic anemia treated intensely. Serum potassium levels should be carefully monitored, and supplementation provided as needed."

I took a small dose of B12, unwittingly B12 deficient, as my labs did not reflect this. Within 7 hours I became exhausted, I had heart palpitations, and I passed out. I was only 25 years old. Luckily, I remembered reading the bit about potassium and when I regained consciousness, I took some and called an ambulance. Once at the hospital, they monitored my potassium levels and found they fell another 0.6 within a couple hours, while the B12 did it's thing. That is massive.

I needed very large doses to keep myself out of the hospital - 80meq per day. That is the equivalent of about 80 bananas. So, for people suggesting a banana suffice for potassium loss, I have to say I strongly disagree and potassium levels should be closely monitored when beginning B12 supplementation. Most, thankfully, won't react as violently as my levels did, but everyone should know that making new Rbcs and DNA synthesis requires a TON of potassium.

I'm too tired now to add the folate bit, but will do so tomorrow.

Written by
rachelabc profile image
rachelabc
To view profiles and participate in discussions please or .
Read more about...
11 Replies
Gambit62 profile image
Gambit62Administrator

rachelabc - you would seem to be at a particular extreme - and I've never come across a similar case. It is likely to be more to do with the way your body processes potassium than the B12.

What exactly was the dose of B12 that you took and was it oral or injected?

I would not advise anyone to take the quantities of potassium you mention without medical supervision as in the vast majority of people they would lead to an overdose - hyperkalemia - which can be just as damaging.

Gambit62 profile image
Gambit62Administrator in reply toGambit62

also, do you know for sure that you had megaloblastic anaemia?

rachelabc profile image
rachelabc in reply toGambit62

It is not the way I process potassium; as stated, it is clearly documented in medical literature to occur in some cases of B12 depletion, due to rapid RBC synthesis.

Also, I did not recommend that anyone take such high doses of potassium. I gave my dose strictly as an example of what an extreme case looked like, and instead urged that people have their potassium levels closely monitored by a doctor.

The dose of b12 was only 1mg and it was taken sublingually.

fbirder profile image
fbirder in reply torachelabc

The depletion of potassium due to rapid reticulocyte formation happens over days, not hours. So it’s extremely unlikely that yours was caused by that. emedicine.medscape.com/arti...

Reticulocytosis starts in 3-4 days and peaks at 1 week.

If your labs didn’t reflect a B12 deficiency how did you decide you were deficient.

If your labs didn’t indicate macrocytic anaemia then you wouldn’t have undergone any rapid reticulocyte formation. So it couldn’t cause and potassium loss.

RachelSinCO profile image
RachelSinCO in reply tofbirder

That's actually not true Fbirder. We are actually taught in med school to closely monitor potassium levels after B12 repletion in those with severe deficiency for the first few days, as this is when the acute (and potentially dangerous) reaction will occur, if it is to.

Labs are not reliable indicators of B12 deficiency. There are several reasons that things like B12 deficiencies and anemias are masked, or missed, in labwork. Thus, B12 deficiency is to be treated based on symptoms and response to treatment.

And, on the topic of potassium: potassium *can* be dangerous - if you take too much at one time, have issues with kidney function or are taking medications which impair potassium excretion. The dosages mentioned in this thread are at the higher end for daily supplementation, but the dosage is not in itself dangerous. Nearly 50meq (from food) is the RDA, for the purpose of perspective. At 99mg per over the counter pill, it would take 50 of these pills to equal the RDA, let alone the 80 required for an 80meq dose.

I think the takeaway here is simply raising awareness for the fact that yes, in a small population of B12 deficient patients, a serious and life-threatening situation can develop upon initial repletion of B12 stores if potassium is not monitored and supplemented as needed. However, most people won't notice symptoms of potassium deficiency until after a couple weeks; this type of slower depletion is much less dangerous and easier to correct.

Frodo profile image
Frodo

Well, there's a bit of a problem in that it's highly unlikely a person will get any medical advice or monitoring of potassium, folate, or iron while having B12 injections, and definitely not if taking an OTC tablet or sublingual. Maybe if you ask for it, or if you were in hospital, but otherwise I've never heard of anyone being monitored like this.

fbirder profile image
fbirder in reply toFrodo

When I have a blood test for my diabetic screening I always have a potassium level measured. The last one (Monday) was 4.3 mmol/L - smack in the middle of the range. That’s a total of roughly 25 mmol or just under 1 g in total.

Frodo profile image
Frodo in reply tofbirder

That's good. But have you had one in relation to having B12 injections?

I don't think I've ever had one unless it's part of the complete blood count or whatever they're called. Maybe with the endocrinologist 6 years ago.

RachelSinCO profile image
RachelSinCO in reply toFrodo

You're right, most won't. But, that's why it's important to be your own advocate and ask to be tested. If the doctor is supplying B12 injections, they should at least be aware of the interactions B12 has with potassium, and I can't see a reason for them denying this request for testing. As an aside, potassium shouldn't need monitored for longer than the first week; the first month would be ultra conservative and likely unnecessary. I guess if you made it past the first week of (high dose) B12 supplementation, you're likely in the clear.

Frodo profile image
Frodo in reply toRachelSinCO

I had mine at weekly intervals, not loading doses over a week, and was aware of potassium and the symptoms of low potassium so was watchful. My GP didn't bring it up. I would have asked had there been a problem. Needing extra or regular monitoring is one of the things that I assume would make getting B12 treatment more of an issue with the current pressures many surgeries are facing.

Bellabab profile image
Bellabab

The one small banana a day is to ensure sufficient potassium in the Newcastle diet which is very extreme. It is a good insurance and works well with most people.

Not what you're looking for?

You may also like...

How to take B12 injections....

Can someone pls tell me how should I take vitamin B12 injections? My internal medicine doctor...
sa1234 profile image

Checking on my understanding of Folic Acid

The friend I am giving information to and not advising has Serum Folate test results of 3.3 ug/l....
WIZARD6787 profile image

Need some help re B12 metabolism

Hi started my B12 loading dose yesterday (yay!) and have 6 in total lined up. I've read a few...
Onefish profile image

B12 217ng/L low folate/serum ferritin

Hello,I have been suffering with exhaustion, lighted head and occasionally hard to catch my breath....
Sotired3 profile image

Folder levels high

Hi all! It's been awhile since I posted anything. I've been doing about 5 injections of...
ndodge profile image

Moderation team

See all
Foggyme profile image
FoggymeAdministrator
Gambit62 profile image
Gambit62Administrator
taka profile image
takaAdministrator

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.