@bassetmom thank you taking the time to add your experiences to this thread.
I have had this condition for about 8 years now.
Magnesium is the one supplement that has consistently had a positive effect on the nocturnal leg cramps. However, if I take a strong anti inflammatory I can forgo the magnesium and not get the cramps. This suggests to me that inflammation is playing a part in what I believe is a multi faceted issue.

Finding I had B6 toxicity (after taking magnesium with 25mg of B6 in it) was a big surprise. Here (in Australia) the safe dose of B6 has been lowered from 100mg to 10mg per day.

I had surgery on my left ankle that preceded the onset of the cramps. Initially the cramps were in that lower leg and I blamed it on the surgery. That is when I started taking the magnesium (with the B6), in 2017. I discovered the B6 toxicity in January 2025 when it started to become recognised as a ‘thing’ and the symptoms matched mine and I got tested. The B6 dropped back to normal levels within a few months of stopping all supplements but the cramps returned - interestingly in both lower legs.

I have found a supplement containing just magnesium that has eliminated the cramps unless I get inflammation in my feet by standing too long, wearing shoes that do not roll my arches out, or sitting too long and my lower back gets inflamed (an earlier car accident injury).

I believe I have many co-conditions that cannot be treated in isolation.

Peripheral neuropathy caused by the B6 toxicity has contributed to what I believe to be vascular disease in my feet. Massage helps.

Burning mouth is exacerbated by sugar and alcohol.

I believe blood pressure has a direct effect on nocturnal leg cramps.
I’d be interested to know if those in this group who find heat pads helpful have high blood sugar (warmth dilates your blood vessels and decreases blood pressure). I have low blood pressure and I find cooling them helps.
I was asked to take medication to slow my heart rate, to take an image (angiogram) of my heart and the cramps that night were the worst I’ve ever had.

My current leg cramp cure includes daily magnesium, good hydration, gentle exercise, no alcohol at least 3 hours before bed, no sugar after noon, shoes with good arch support (that roll my ankles outwards) and stretching my lower back before sleeping.

I think my nocturnal leg cramp issues are vascular and linked to blood distribution and inflammation levels.

Homocysteine levels may be elevated due to low B3, B6 and B12 levels due to MTHFR mutation which affects metabolism of these vitamins.

I have found leg cramps to be a multifaceted problem that is a symptom of a larger issue that requires a process of elimination, and it’s unlikely to be a single source cure.

I really appreciate all of the input others have put into this discussion. Everyone has been helpful in shining a light in another dark corner where I had not previously looked.
I am most grateful to everyone who has contributed. May you all find comfort and good health.