Magnesium deficiency is a condition in which patients have a low level of dietary magnesium in the blood. Magnesium is a mineral which is important for many processes in the body, including regulating muscle and nerve function, blood sugar levels and blood pressure, and making protein, bone and DNA. 

A deficiency in magnesium is uncommon in people who are otherwise healthy and have a normal intake of magnesium in their diet but it can be caused by low levels of dietary intake, or excessive loss or poor absorption due to some medical conditions, chronic alcoholism or the use of certain medication.

Symptoms of magnesium deficiency include dizziness, fatigue, muscle weakness, leg cramps, hormonal imbalance, bone weakening and irregular heartbeat. Magnesium deficiency can increase the risk of hypertension, cardiovascular disease, type 2 diabetes, osteoporosis, and migraine headaches.

Anyone who is taking calcium supplements should also take magnesium to ensure their calcium intake is properly metabolized and avoid the risk of arterial calcification and cardiovascular disease, as well as kidney stones.

Magnesium deficiency is usually treated by including foods with high magnesium content in the diet and with magnesium supplements.