Poranne skurcze łydek

Spróbuję podbić potas. Co do badań z krwi: magnez i potas są głównie poza krwią („Less than 1% of total magnesium is in blood serum, and these levels are kept under tight control” [https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/], „Total body potassium is approximately 55 mEq/kg body weight. Of this amount, 98% is in the intracellular compartment (primarily in the muscle, skin, subcutaneous tissue, and red blood cells) and 2% is in the extracellular compartment” [https://www.ncbi.nlm.nih.gov/books/NBK307/]) i celowość ich oznaczania z krwi jest kwestionowana. Jedynie sód z krwi ma jakieś znaczenie bo jest go poza komórkami aż 50% („The mean body content of sodium in the adult male is 92 g, half of which (46 g) is located in the extracellular fluid” [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3951800/]).