Overview of magnesium deficiency
Magnesium deficiency is a mineral abundant in the body that is obviously present in many foods, and available as a dietary supplement. Magnesium is a cofactor in more than 300 enzyme systems that control various biochemical reactions in the body, including protein synthesis, nerve function, blood glucose control, and blood pressure regulation. Magnesium is necessary for energy production, oxidative phosphorylation, and glycolysis. It contributes to the structural growth of bones and is necessary for the synthesis of DNA, RNA, and the antioxidant glutathione. Magnesium also shows a role in the active transport of calcium and potassium ions across cell membranes, a process that is important for nerve impulse conduction, muscle contraction, and normal heart rhythm.
Symptoms of magnesium deficiency
Early signs of low magnesium include:
- Decreased appetite
As magnesium deficiency worsens, symptoms may include:
- Muscle cramps
- Muscle spasticity
- Personality changes
- Abnormal heart rhythms
Causes of magnesium deficiency
Low magnesium is typically due to decreased absorption of magnesium in the gut or increased excretion of magnesium in the urine. Low magnesium levels in otherwise healthy people are uncommon. This is because magnesium levels are largely controlled by the kidneys. The kidneys increase or decrease excretion (waste) of magnesium-based on what the body needs.
Continually low dietary intake of magnesium, excessive loss of magnesium, or the presence of other chronic conditions can lead to hypomagnesemia.
Hypomagnesemia is also more common in people who are hospitalized. This may be due to their illness, having certain surgeries, or taking certain types of medication. Very low magnesium levels have been linked to poorer outcomes for severely ill, hospitalized patients.
Conditions that increase the risk of magnesium deficiency include gastrointestinal (GI) diseases, advanced age, type 2 diabetes, use of loop diuretics (such as Lasix), treatment with certain chemotherapies, and alcohol dependence.
Celiac disease, Crohn’s disease, and chronic diarrhoea can affect magnesium absorption or lead to increased magnesium loss.
Type 2 diabetes
Higher blood glucose levels can cause the kidneys to excrete more urine. This also causes a greater loss of magnesium.
Alcohol dependence can lead to:
- Poor dietary intake of magnesium
- Increased urination and fatty stools
- Liver disease
- Throwing up
- Renal insufficiency
All of these conditions have the potential to consequence in hypomagnesemia.
Diagnosis of magnesium deficiency
Your doctor will diagnose hypomagnesemia based on a physical exam, symptoms, medical history, and a blood test. A blood magnesium level doesn’t tell you the amount of magnesium your body has stored in your bones and muscle tissue. But it’s still helpful for indicating whether you have hypomagnesemia. Your doctor will likely also check your blood calcium and potassium levels.
A normal serum (blood) magnesium level is 1.8 to 2.2 milligrams per deciliter (mg/dL). Serum magnesium lower than 1.8 mg/dL is considered low. A magnesium level below 1.25 mg/dL is considered very severe hypomagnesemia.
Hypomagnesemia is typically treated with oral magnesium supplements and increased intake of dietary magnesium.
An estimated 2 per cent of the general population has hypomagnesemia. This percentage is much higher in hospitalized people. Studies estimate that nearly half of all Americans and 70 to 80 per cent of those over the age of 70 aren’t meeting their daily recommended magnesium needs. Getting your magnesium from food is best unless your doctor tells you otherwise.
Examples of magnesium-rich foods include:
- Whole-grain cereal
- Black beans
- Whole wheat bread
- Baked potato with the skin
If your hypomagnesemia is severe and includes symptoms such as seizures, you may receive magnesium intravenously, or by IV.
If left untreated, this condition can lead to:
- Heart attack
- Respiratory failure
Treating the condition that is causing low magnesium levels can help.
If you play sports or other vigorous activities, drink fluids such as sports drinks. They cover electrolytes to keep your magnesium level in a healthy range.
Outlook for low magnesium
Hypomagnesemia can be caused by a variety of underlying conditions. It can be treated very effectively with oral or IV magnesium. It’s important to eat a balanced diet to ensure you’re getting enough magnesium. If you have conditions such as Crohn’s disease or diabetes or take diuretic medications, work with your doctor to ensure that you don’t develop low magnesium. If you have symptoms of low magnesium, it’s important to see your doctor prevent the development of complications.