Symptoms
Possible symptoms of clinically manifest magnesium deficiency include:
- Neuromuscular symptoms such as a tremor, muscle spasms, fasciculations (involuntary muscle movements), seizures
- Central disorders: Apathy, fatigue, dizziness, delirium, coma.
- Cardiovascular disorders: ECG changes, cardiac arrhythmias, palpable heartbeats, hypertension.
- Osteoporosis, Altered glucose homeostasis.
Magnesium deficiency is often accompanied by calcium and potassium deficiency. However, many patients are also asymptomatic. Magnesium deficiency can promote the development of type 2 diabetes and lead to worsening of the disease.
Causes
Magnesium is a mineral and a cofactor of numerous enzymes. It is involved in hundreds of metabolic reactions. Magnesium is a physiological calcium antagonist and reduces acetylcholine release at skeletal muscle. It is found in humans primarily in cells, bone, and muscle. The extracellular amount is small. Magnesium is involved in bone mineralization, muscle relaxation, energy production and signal transmission in the brain, and stabilizes DNA. Causes of deficiency are (examples):
- Insufficient absorption, for example, in malnutrition, alcohol dependence, vomiting and malabsorption.
- Medications, for example, diuretics (e.g., loop diuretics, thiazides), proton pump inhibitors (PPI), laxatives, ciclosporin, cisplatin, and aminoglycosides.
- Redistribution in the body, increased demand.
- Increased excretion, for example, due to diarrhea or kidney disease. The kidneys play an important role in excretion and regulation.
- Genetic alterations, for example, mutations in genes encoding transport systems such as TRPM-6 and TRPM-7. These are involved in the absorption of magnesium in the intestine.
Diagnosis
Diagnosis is made on the basis of patient history, clinical symptoms, with an ECG, laboratory methods and other tests. This is to identify the exact cause. Because only a small fraction of total magnesium is found in the blood, serum concentrations may be within the normal range even in the presence of a deficiency.
Nonpharmacologic treatment
- Therapy of the cause
- Adjustment of drug treatment, for example, administration of ranitidine instead of a proton pump inhibitor
- Magnesium-rich foods
Drug treatment
For drug therapy, magnesium is available in various dosage forms, for example, effervescent tablets, granules, capsules and tablets. Intravenous injection preparations are also commercially available for acute treatment. In general, renal function must be taken into account. Caution is advised when taking other drugs at the same time, because magnesium can reduce their absorption into the body. Possible adverse effects include soft stools and diarrhea. Other deficiencies (e.g., calcium, potassium) should also be corrected.
