Screen Shot 2015-10-08 at 1.39.10 PMEver heard of Electrolytes? They are electrically-charged minerals/ions found in your body, usually blood and other body fluids, and their balance is critical for optimal function of all your cells and organs! The most common electrolytes are:

  • sodium

  • potassium

  • chloride

  • calcium

  • magnesium

  • phosphorus

And one thyroid and adrenal patient discovered the hard way how important potassium in particular was, how serum lab results don’t tell the whole story, and how low levels affected her with muscle spasms and weakness. She stated:

I have been to at least 6 doctors over the past seven years and read thousands of websites, hunting for the cause of my severe muscle spasms, explains Valerie. They all ruled out potassium, a potentially likely cause, because my serum lab result, 4.2, was right smack in the middle of the normal range.?

So she was forced to live with her worsening muscle issues, spasms, weakness and pain because all labs were normal and those that weren’t, didn’t pertain. Even her insulin-dependent Type 2 Diabetes was well-controlled. And she knew it was all threatening to put her out of work. It was bleak.

But a surprising change was to come. She states:

About 2 months ago, someone mentioned potassium helping with fluid retention, the latter I’ve had for the last 15 years and took Dyazide, a potassium sparing diuretic.

She also learned about getting an RBC (red blood cell) potassium lab as it shows what’s inside the cells rather than in serum (as usual labs show). And the results? It came back LOW.

At one point, she had to work her way up to 2850 mg, which might be too high for some, but she seemed to need that much. Potassium in a combination of chloride and gluconateand below, in her own words, were the results:

  • No more muscle spasms and the weakness and pain is leaving more daily!
  • My IBS suddenly STOPPED!
  • My insulin needs are HALF what they were before this supplement, and blood pressure & pulse are both down.
  • ALL fluid retention is gone! I dropped 18 pounds the first month in just fluid weight.

She concludes: I have since learned that being hypothyroid can cause potassium losses for some, as does ANY steroid which I had been on for necessary adrenal support. Diabetes with a low carb diet also predisposes us to lose intracellular potassium into the serum which is probably why my serum labs looked normal in the face of extreme shortage. I hope many will see this and at the very least get RBC potassium labs done and if you have high BP or fluid retention, reach for potassium before a diuretic!


Even without being inspired by the above patient’s discovery, there is good research out there for eating potassium rich foods or using supplementation if your levels are proven to be low with testing. The LA Times reported a study which stated that consuming twice as much potassium as sodium might halve your risk of dying from cardiovascular disease, stated by epidemiologist Paul Whelton, president and chief executive of the Loyola University Health System in Chicago and one of the authors of the study.

NOTE: Using BOTH the serum and RBC labs tests for potassium can be important to discuss with your doctor. Serum testing will help make sure your potassium levels aren’t too high, especially when on supplementation. High levels can be dangerous. The RBC labs can test the cellular level of potassium if you suspect you are low.

What do I look for in my labwork??

  • For healthy adrenal/thyroid function, sodium should be 142-144 ideally, we’ve noticed, though some are as low as 140 and seem fine.
  • Potassium seems to be ideal in the 4.0-4.5 range and wouldn’t need supplementation to the best of our knowledge.
  • RBC potassium needs to be in the 70-95 percent of it’s range for best health, as we understand it.

So remember to ask your doctor to do an Red Blood Cell (RBC) Potassium lab in addition to simply serum. The RBC will reveal your cellular level of potassium, which the serum tests don’t. And don’t assume you need to go as high as the patient above unless you have proof of low potassium and are working directly with your doctor.

P.S. Magnesium helps pump sodium out of your cells, and potassium into the cells….both good reasons to get magnesium tested as well. Janie, the author of the 2019 updated revision STTM book and creator of this website, found herself with bottom-of-the-range magnesium from the RBC test in early 2010, in spite of feeling quite well thyroid-wise.

Important note: STTM is an information-only site based on what many patients worldwide have reported in their treatment and wisdom over the years. This is not to be taken as personal medical advice, nor to replace a relationship with your doctor. By reading this information-only website, you take full responsibility for what you choose to do with this website's information or outcomes. See the Disclaimer and Terms of Use.