Cerebrospinal fluid magnesium

Magnesium is the second cation in the intracellular fluid. Adults contain 20-30g of magnesium, about 2/3 of which are distributed in bone tissue, and the rest are distributed in muscle and other soft tissues. Plasma magnesium content is very small, and striated muscle, heart, liver, kidney, brain and other tissues contain 6-10 times the magnesium content of plasma. Free magnesium in plasma accounts for about 2/3, and the other 1/3 is called magnesium when it is combined with protein. However, only 1/3 of the intracellular magnesium is in a free state, and it is not easy to escape from the cells. The daily magnesium requirement of normal people is about 200mg. It comes from food, is absorbed by the small intestine, and excreted by the kidneys.