This is my educated guess, partly because potassium helps me. This mostly concerns long covid with fatigue.
Part of the reason why long covid and CFS runs into potassium deficiency so much is that potassium is pumped into cells with a sodium-potassium ATP pump. Almost all the potassium is inside the cell while almost all of the sodium is outside the cell. That is how cells like neurons store potential energy, it is like a battery, all the potassium wants to flow out of the cell and all of the sodium wants to flow into the cell. If a neuron needs to gain positive charge it lets in sodium, if it wants to lose positive charge it lets out potassium. Of course other electrolytes are used but sodium and potassium are the main ones.
In fact, all cells expend a large fraction of the ATP they produce (typically 30% and up to 70% in nerve cells) to maintain their required cytosolic Na and K concentrations. For neurons, the Na⁺/K⁺-ATPase can be responsible for up to 3/4 of the cell's energy expenditure.
What this means is that when energy gets very low, the pumps cannot function well and blood potassium rises, then the kidneys excrete it because they are supposed to excrete high blood potassium. Then when energy in the cells rises again and potassium is pumped back into the cell, a blood deficiency is triggered.
Then because potassium is low, muscles cramp up and microcirculation is lowered, triggering hypoxia, which further impacts cell energy production.
Taking things like anti oxidants, B vitamins or magnesium can also boost ATP production and cell metabolism, causing them to intake more potassium, leading to blood deficiency. If I take any of those I usually get symptoms of potassium deficiency such as fatigue, constipation and ADHD symptoms.
This is part of how refeeding syndrome works. Severe starvation followed by food intake can cause major electrolyte deficiencies that can cause death. Obviously people with CFS and Long Covid are not that serious, this post is about minor electrolyte deficiencies.
Sources of potassium are milk, bananas, avocados, potatoes. You can also get it as salt substitutes such as "no salt" which are just potassium chloride, 1/4 teaspoon is equal to around 700mg of potassium. Salt substitutes are available at some supermarkets and on amazon, just look for potassium on the back label. I take 1/4 teaspoon and wash it down with water every night before bed, I take it before bed so that my body can balance electrolytes overnight. The daily recommended daily dose of potassium is between 2,000mg and 5,000 mg.
I had a nasty bout of COVID beginning 3.5 weeks ago. Started testing negative around 12 days after symptoms began. I had pretty bad symptoms but wasn't hospitalized. Although I did go to the ER a few days ago because I didn't seem to be improving much, bad fatigue, rapid heart rate, dizziness when standing up. The ER said my chest x-ray and blood work all came back normal and sent me home without a clear diagnosis.
Anyhow, my heart rate goes up like crazy from just sitting up, or even worse, standing up. It doesn't decrease and normalize after a few minutes. I also feel very faint and dizzy upon standing.
My resting heart rate goes from about mid 60s when relaxed to around 110 just standing still. If I walk around it goes up even more.
I used to be able to take brisk mile long walks and my heart rate would be around 110 to 120.
Have any of you folks experienced this? If so, how long did it take for you to get better? What helps with recovery?
I’m 3 months 1 week since testing positive and have been pretty housebound and bedbound for the past two months. Some days I can manage a few small walks and making food and doing chores, working a few hours, but the fatigue, neurological shit is awful and I feel like I don’t have enough energy to power my body.
I’m really scared that I’m never going to get better and just get worse and worse. Can anybody offer some hope please. I’ve lost five years already due to a bad reaction to a medication that made my nervous system really fragile. I’m pretty depressed and wanting to give up and wonder if hanging on is worth it.
Please nothing negative my brain can’t take it