That's useful; thanks, Crux. Salt does seem to work like a charm for my muscle twitches. With lots of people talking about magnesium highlighting a potassium deficiency - which can also cause cramps - it gets rather confusing. I'm going to try magnesium glycinate, perhaps. As for compromised cell membranes, this would make sense. In the Methylation Panel I have high serum folic acid, which he also suggests might be related to compromised membranes.