Hence the relative influence of Mg is larger. Statistics on Mg should be based on the Mg water content of the working rather than the living area. There is a long history of Mg deficiency in cattle, mainly high-producing milk cows, with frequent occurrence of tetany and heart disease. Mg are affected, and the variety of symptoms also suggests a combination of factors, of which Mg deficiency is a very important one. In the human the relation of Mg and heart disease is somewhat different, at least quantitatively.
Magnesium has all the required properties to protect the heart.
It ensures the normal quiet heart rhythm. If this is unduly accelerated by toxic factors or other stress, Mg may reverse the effect. It also counteracts digitalis, epinephrine and other toxic agents used to induce heart disease experimentally in animals. In all of these conditions Mg restores the original rhythm and effective functioning of the heart. On the other hand, active Mg is lost from the ischaemic heart, even before loss of sodium occurs, and it is replaced later by inactive Mg, probably in the form of insoluble phosphate.