Blood clotting (intravascular thrombosis, heart attacks and strokes)

Clotting is a normal response to blood vessel damage. When a blood vessel wall is damaged, tiny blood cells called platelets activate. These platelets adhere to a damaged surface and release sealing agents like fibrin. Magnesium regulates the activation of these platelets by controlling calcium levels and maintaining cell receptors. That’s why magnesium is sometimes called an anticoagulant.

Magnesium deficiencies increase the risk of unnecessary platelet activation, forming more clots in blood vessels. These clots may block blood flow to the brain or heart, increasing the risk of strokes and heart attacks. 

High Blood Pressure

Besides preventing blood clots, magnesium also acts as a natural vasodilator. Magnesium, as a calcium antagonist, allows the heart muscles and the smooth muscles of the arteries to rest and relax, reducing blood pressure. If there is insufficient magnesium, these blood vessels constrict, raising blood pressure.

Magnesium’s role in maintaining healthy blood pressure has a lot to do with its ability to activate the sodium-potassium pump. Even if a magnesium deficiency occurred and a sufficient supply of potassium was available, it would likely not make it into the cell to allow for proper sodium regulation.

Arrhythmia

Like elsewhere in the body, magnesium regulates concentrations of potassium and calcium in the heart as well. These concentrations control and coordinate the rhythm of electrical signal and muscle contractions.

The Canadian Cardiovascular Society recommends that hospitals administer magnesium intravenously in order to reduce the risks of atrial fibrillation.