Hi, Jude. I have a long experience with foot and leg cramps -
I get F&L cramps if I have too much wine. I get F&L cramps if I have too much exercise. I get F&L cramps if I make a radical change in my diet. I used to do an allergy treatment that required a total change in diet for a couple of days before and after - and although I was still eating proteins, carbs and fats (not much fats) - I would cramp up. Driving a long trip gives me F&L cramps. I always have a bottle of the Hyland homeopathic remedy for F&L cramps on my bedside table and in my purse.
What I THINK is happening is that there is a slight diuretic tendency with MMS - and so our minerals can become a little out of balance - it's why I tell people I'm working with to be sure to get enough water - not just the water with their MMS. Also, for me, I find that when I'm actively on MMS (or CDS) my food "desires" change - I don't seem to want as much sugar - I definitely had no desire for wine - and that shift in diet could cause my cramps. They usually don't recur night after night - just in that initial rebalancing period. But this is my personal theory from what I've observed in myself.
Definitely, you may want to take an extra mineral tablet or capsule, along with your vitamins. It will support your immune system. You might do a sole (or solay, as some people pronounce it) Or, get some Quinton sea water (not cheap....) and take a bit of it each day. Quinton has a LOT of minerals.