Hello Ferg,
Welcome to the group. If I recall correctly, that's exactly what my doctors told me (that nothing could be done about it) when the right bundle branch block showed up. I was surprised (and so were my doctors) when it disappeared.
As I recall, I was taking a misrepresented product when the magnesium deficiency developed. I was taking 200 mg of magnesium glycinate from Vitacost. I found out later (after they lost a lawsuit) that the magnesium was "buffered" with about 50 % magnesium oxide.
The explanation can be read here).
The reason why I was taking 200 mg when I thought I was taking 400 mg is because I misread the label. It said 200 mg on the front label, so I assumed that each tablet contained 200 mg of magnesium glycinate. But this was a mistake. It actually contained 100 mg per tablet (200 mg was considered the dose) and 50 % of that was magnesium oxide. Magnesium oxide is virtually worthless as a supplement because humans can absorb only about 4 % of it. So for years, even though I thought I was getting 400 mg of magnesium, I was only getting about 100 mg.
So when I figured out the problem, I increased the dose to 600–800 mg of magnesium glycinate (Doctor's Best brand) and magnesium citrate (both are highly absorbable, but too much magnesium citrate acts as a laxative, so I made sure that I never took more than 300–400 mg of it). Magnesium should be scattered throughout the day of course, with meals. So that resolved my magnesium deficiency problem. I cut back to about 400–500 mg after 5 or 6 months.
But that's not the end of the story. Vitamin D enhances the uptake of magnesium. I always try to keep my vitamin D level in the 40–80 ng/dL range in order to optimize the function of my immune system. Taking that much magnesium is OK, as long as your kidneys are working well so that they can eliminate any excess amount in the blood. But if the functioning of your kidneys should become compromised, then blood levels of magnesium can build up to excess levels rather quickly (especially if you have optimum vitamin D levels).
Magnesium is a vital electrolyte. It not only works with insulin to transport nutrients to cells during food digestion, but it also helps to regulate vital cardiovascular functions, breathing, body temperature regulation, muscle contraction/relaxation and several hundred other chemical processes in the body. So too little or too much in circulation can affect all these processes. It can cause a heart attack for example, if things get too far out of hand either way.
The years of magnesium deficiency apparently damaged my kidneys. Doctors don't monitor kidney function anywhere near as well as they should. In March of 2016 my heart began to skip beats — a lot of beats. My doctors couldn't see any reason, but when I looked at my eGFR (estimated Glomerullar Filtration Rate) it was rather obvious that my kidneys weren't able to handle large amounts of magnesium in the blood, so my serum magnesium was probably spiking at times, damaging my heart. I cut my dose to 300 mg of magnesium glycinate and my heart promptly returned to functioning normally. About three weeks later I had a stroke. Maybe it was just a coincidence, but I can't help but believe that it's all tied together. I had had some mini-strokes over the years prior to this.
Anyway my point is — be careful with magnesium. It's a vital but potent medicine.
Again, welcome to the forum, and please feel free to ask anything
Tex
