I don't take near those levels, yet I've still had noticeable improvements especially with respect to the Raynaud's syndrome I was experiencing. Since I started the Ca, Mg, Zn, and D3 combo it has yet to reoccur (and it's been 1.5 years since).

NHE
Zn plays a clear role in the synthesis, storage and secretion of insulin as well as conformational integrity of insulin in the hexameric form, the decreased Zn, which affects the ability of the islet cell to produce and secrete insulin, might then compound the problem...
The behaviour of proinsulin and insulin in the presence of zinc suggests it plays an important role in insulin's production in the B-cell for the vast majority of animal species...
with magnesium it's best absorbed in the lower intestine and supplements get dealt with higher up. so really, it's best to try to get as much as you can from food, mmm chard spinach and pumpkin seeds... (ugh, i'll take the spinach thanks lol!)...it appears that zinc can induce an increase in glucose transport into cells and potentiate insulin-induced glucose transport, likely acting through the insulin-signaling pathway.
Magnesium deficiency has been associated with insulin resistance (IR) and increased risk for type 2 diabetes in adults...
Magnesium (Mg) is one of the most abundant ions present in living cells and its plasma concentration is remarkably constant in healthy subjects. Plasma and intracellular Mg concentrations are tightly regulated by several factors. Among them, insulin seems to be one of the most important. In vitro and in vivo studies have demonstrated that insulin may modulate the shift of Mg from extracellular to intracellular space...
The World Health Organisation estimates that a third of the global human population, including in developed countries, is zinc deficient.
Arterial vascular tissue is composed largely of smooth muscle, which regulates constriction and dilation of the blood vessel, and a single layer of endothelial cells, which line the luminal surface and are in direct contact with the circulating blood
we have given these mice diets similar in composition to human western type, high fat foods with zinc levels across the range consumed by many adults in the UK. Our preliminary results show that within 13 weeks of eating the diet, marginal zinc deficiency encourages the development of atherosclerotic lesions in the aorta