@datura - That's too bad your doctor can't help you with your refeeding concerns. I don't know what type of doctor would be best for that. It has occurred to me that doctors who specialize in anorexia might be very good for people with me/cfs because we have so many metabolic abnormalities and apparent problems with refeeding issues when we add in various supplements.
Re potassium: I'm assuming your potassium test measured potassium in the blood and not intracellularly. Most potassium tests measure potassium in the blood or sera. There is specialized testing which measures intracellular electrolytes:
http://www.exatest.com/physicians.htm I had it done once to measure intracellular magnesium.
So assuming your blood potassium was 4.3, yes that's in the normal range, but it does not tell you what your intracellular potassium was. It is possible to have normal potassium levels in the blood and low intracellular potassium. If you look at the link I provided in the first post I did above, it explains how people with me/cfs tend to be low in intracellular potassium despite normal blood work. I don't know if you have me/cfs though I expect others might have similar issues.
I'm not suggesting you take a potassium supplement. But I think it's possible you may have low intracellular potassium, particularly since you've started taking folate and B12, which are notorious for causing potassium levels to drop because they increase the need for potassium. Many on the board (including me) need more than the RDA of 4500 mg of potassium. So your 2 coconut waters just may not be enough, which is why I suggest adding in some low-sodium V8 or low-sodium vegetable juice which is high in potassium and low in sugar (the low in sugar part is important for me) and see if it helps. I would drink 2 or 3 glasses, in addition to your coconut water. It is next to impossible, if not impossible, to get too much potassium in foods. Also, the RDA is the minimum amount of potassium necessary.
Here's one study which mentions this issue:
https://www.ncbi.nlm.nih.gov/pubmed/3627537
Also check out this thread by user Freddd, who is extremely knowledgeable about methylation and folate and B12. He talks specifically about potassium and hypokalemia and methylcobalamin:
http://forums.phoenixrising.me/inde...es-to-healing-via-induced-deficiencies.41605/
If you did try the low-sodium V8 and saw an improvement, you might consider a potassium supplement. The 1000 mg I'm taking is less than 25% of the RDA. I titrated up to this dose over a couple of days, starting with around 400 mg in divided doses, until my symptoms abated. It is important not to take a large dose all at once.