Under ideal circumstances, magnesium should come form a well balanced diet. Magnesium is involved in many biological processes that can range fm bone health to blood pressure control to protein synthesis. It is one of the supplements in my top ten list.
I can tell you that nearly half of Americans do not reach their minimum Magnesium requirement. It is 420 mg for men and 320 mg for women. You can have a serving of almonds, cashews, or spinach to get 20% of your daily needs. It should be supplemented. It is a vital nutrient.
Magnesium has many roles, but one not discussed is its role in better digestion. Magnesium can help relax the intestinal wall and draw water into the colon. This is why the magnesium form of magnesium citrate is in laxatives.
Magnesium is also great for calmness and for sleep. It helps regulate the heart rhythm.