Potassium intake

After reading the success stories about increasing potassium intake I thought I should give it a try. So for the last month I made sure to get about 3500-4000mg of potassium in food and if I don’t reach 4000 by the evening I am supplementing with 448 mg of potassium citrate (1/4 teaspoon powder from NOW). I am happy to say that I did not have any episodes since I started this regimen, but I went for several months without afib before so I can’t say for sure whether it is working yet.
But since I increased potassium intake considerably I thought it would be a good idea to have a blood test. And the result is a bit concerning. My BUN/Creatine ratio increased to 32.3 (reference range: 10.0-28.0). Everything else is normal: BUN 20, creatine 0.62, eGFR 95. The only other abnormality is a slightly elevated MPV of 12.2 (reference range: 9-12). I also want to mention that the increase in potassium did not affect the potassium level at all. It is constant at 4.2 mmol/L for the last five years. Doesn’t that mean that my kidneys are getting rid of excess potassium just fine? But why the high BUN/Creatine ratio?

I can't recall the details, but I read several years ago that some kidneys should not be 'irritated' or 'tested' by inordinate or unnecessary quantities of potassium because it's hard on them....some of them. My own creatinine level was deemed high, just out of range, about 12 years ago, but nobody told me about it. When I challenged my GP, he shrugged and said they kept an eye on it and it had stabilized, so nothing to worry about.

People eating nuts and some leafy green and root vegetables even once a week should have relatively robust levels of K, Mg, and C in their cells and in their serum. Some clearly do not, though. When I was put on amiodarone four years ago due to a chaotic rhythm, the first thing they had me take were two large white tablets for K, which was a surprise for me. Ever since, I salt my afternoon coffee with a little K salt, but I also have a handful of pistachios every day, I grow beets, and otherwise try to ensure I get enough.

But, to be direct with your question, my understanding is that the kidneys have to work harder to rid the system of high levels of K. This is reflected in higher indicators, but it might not be the only reason yours are high...it's worth inquiring.

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Edda
And the result is a bit concerning. My BUN/Creatine ratio increased to 32.3 (reference range: 10.0-28.0). Everything else is normal: BUN 20, creatine 0.62, eGFR 95.

What were BUN & creatinine individually before? I don't have medical training, but 0.62 creatinine looks low to me. How is your protein intake and muscle mass. I don't think the potassium, per se, would lower creatine (I take a few grams of postassium ( as citrate) daily as a supplement, Plus I get 3-4 grams/day of potassium in my food. I'm also male & have a fair amount of muscle mass and my last creatinine was 1.14. I'm guessing the ratio is high as because creatinine is low, as BUN looks like it is in range.

Healthy kidneys do a good job of getting rid of excess potassium & your 4.2 is indicative of this.

Thanks gloaming and George. The only time BUN was over 20, actually 21, was one month after I was diagnosed with afib in November 2019. Then it went slowly down, and from 2022 until 2025 it was between 11 and 13. Which makes me wonder whether the high BUN is a stress response. My creatine is pretty consistently between 0.72 and 0.62.
Potassium level is consistently between 4 and 4.2 during the last five years and during the month I increased my potassium intake. The increase in potassium through food and supplements did not make any difference

Good for you Edda!

Potassium should have been the first thing I tried 20 years ago not the last thing. But then I wouldn't have known whether it worked for me or not.

I've been taking 2+ grams of elemental potassium via gluconate or citrate every day for 2 years. My potassium blood plasma levels haven't changed much and Creatinine and BUN/creatinine ration are normal.

I'm so glad I started supplementing with potassium. It has changed my life. I plan to post here in November to celebrate what I hope will be 2 years of NSR (with 2 minor blips).

I am sad to say that last night I had another afib episode. I am now at a loss of what to do. I very consciously wrote down the potassium content of everything I ate and drank and when I reached 4000mg I decided not to take a supplement. Now I am wondering whether I should supplement even if I reach 4000mg in food?

bcampbell37211 how long where your minor blips? My episode last night was 4 hours

Has anyone asked their Dr. if there is a test to determine your potassium and magnesium levels at a cellular level? This is something I have not done myself but am going to because I believe that is more accurate than just checking your serum levels.

I also supplement with extra potassium and magnesium and my serum levels also don't change but I definitely notice I have less ectopic beats.
The majority of people fail to get the recommended 4-5 grams of potassium from food a day myself included and my serum level stays around 4.5.

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EricY
Has anyone asked their Dr. if there is a test to determine your potassium and magnesium levels at a cellular level?

For magnesium, yes. For potassium, not that I know of and I don't think such a test would be useful. Potassium is constantly moving between the vascular space, dissolved in plasma, and the intracellular space in muscle cells. When muscles cells contract and relax they pump K+ in and out of the cell, so the K+ levels in a cell change millisecond to millisecond. This is easily seen by measuring serum K+ levels before and after intense exercise. After exercise, your serum K+ levels will be elevated because muscle cells have "leaked" so much potassium while they worked. In athletes who are training hard, this change in serum levels can be dramatic. One study that measured K+ levels among football (soccer) players during practice found that some of the players reached serum K+ levels of 8.0, which would likely be fatal under any other circumstance. But the thing is, if you have normal kidney function the elevated levels will quickly return to normal.

There's a reason why people with ectopic beats and/or Afib turn to these sites because their Dr. may test their serum potassium and/or magnesium and highly likely will come back as normal and say there's no need to supplement. So, a person may turn to these sites like this one and hear stories of people who had great success with supplementing with extra magnesium and potassium. I remember mentioning to my cardiologist a few months ago that the recommended daily intake of potassium from food is around 4,700mg/day and he had no idea it was that much.

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EricY
Has anyone asked their Dr. if there is a test to determine your potassium and magnesium levels at a cellular level?

There was a test, called the Exa Test that did that for magnesium, potassium & calcium (f my memory serves). all at the same time It was an intracellular test done with a cheek swab. They had data that correlated with tests done on people undergoing open heart surgery. I had the test done in 2004 and it was a driver of my magnesium supplementation,. The company was around for a long time and many members here used it. However, I think they are now out of business and I've not looked for a replacement. For magnesium I think RBC magnesium is a second best. Serum potassium can change rapidly. Some peple have used agricultural meters to check saliva potassium & there is (was?) a correlation equation to relate the two.

Edda,

Sorry I'm slow to get back to you.

I had been in NSR for 6 months from Oct 1, 2024 when on Apr 6, 2025 I had the first blip for 14 hours and self-converted. The second occurred Jan 10, this year (on our 45th anniversary!) That one lasted 16 hours and self-converted. NSR since then.

I can't advise you on whether you should or shouldn't supplement with more K+.

I can say that I have become something of a nut about potassium.

My first episode was in 2004 and because of this forum I had been taking magnesium for 20 years. But I had been scared out of taking potassium by every health care professional I talked to until....I looked at the back of a bag of potato chips. I suggest every afibber look at the Nutrition label on the back of a large bag of potato chips! If 4 or 5+ grams of potassium would stop your heart there would be thousands of dead Americans in front of their TVs on Super Bowl Sunday!

I also found out that the average person on the Standard American Diet (SAD) gets maybe 3 grams of K+/day, so I figured I had at least 2 grams to play with. I even believe that I caused my own afib 20 years ago because I was on the Adkin's diet and cut out the two greatest sources of potassium, potatoes and fruit.

We all want a fix right away, but we all also know that healing takes time. It took months of supplementation with K+ for me to notice longer periods between episodes and shorter episodes. I don't know if I'm there yet but I'm sticking with it and wish you the best.