From the Guidelines
Hypomagnesemia is a condition characterized by abnormally low levels of magnesium in the blood, typically defined as serum magnesium below 1.3 mEq/L, and its causes include poor dietary intake, gastrointestinal losses, alcoholism, certain medications, and kidney disorders, while symptoms can range from mild to severe, including weakness, muscle cramps, seizures, and cardiac arrhythmias. The condition can be treated with oral supplementation for mild cases, using magnesium oxide, magnesium citrate, or magnesium glycinate, and intravenous magnesium sulfate for moderate to severe cases, especially with symptoms like muscle cramps, seizures, or cardiac arrhythmias 1. Some of the key factors to consider in the management of hypomagnesemia include:
- Correcting water and sodium depletion to prevent secondary hyperaldosteronism 1
- Using oral magnesium preparations, such as magnesium oxide, to maintain adequate magnesium levels 1
- Reducing or avoiding excess lipid in the diet to minimize the risk of hypomagnesemia 1
- Considering the use of oral 1 alpha cholecalciferol to support magnesium absorption 1
- Monitoring for signs of magnesium toxicity, particularly in patients with renal dysfunction or those receiving magnesium supplements 1. It is essential to note that magnesium plays a crucial role in over 300 enzymatic reactions in the body, including energy production, protein synthesis, muscle and nerve function, blood glucose control, and blood pressure regulation, which explains the diverse symptoms when levels are low 1. Prevention of hypomagnesemia involves adequate dietary intake of magnesium-rich foods like nuts, seeds, whole grains, and leafy greens, and being aware of the potential causes and symptoms to ensure prompt treatment and management.
From the Research
Causes of Hypomagnesemia
- Inadequate magnesium intake 2, 3, 4
- Increased gastrointestinal losses 2, 5, 3, 4
- Increased renal losses 2, 5, 3, 4
- Redistribution from extracellular to intracellular space 2, 3
- Genetic or acquired renal disorders 2
- Drug-induced hypomagnesemia, particularly related to proton pump inhibitor (PPI) therapy 3, 4
- Short bowel syndrome 4
Symptoms of Hypomagnesemia
- Most patients with hypomagnesemia are asymptomatic 2, 3
- Symptoms usually do not arise until the serum magnesium concentration falls below 1.2 mg/dL 2
- Ventricular arrhythmia is one of the most life-threatening effects of hypomagnesemia 2
- Neuromuscular, cardiovascular, and metabolic features are common manifestations of symptomatic hypomagnesemia 3
- Hypokalemia, hypocalcemia, and metabolic acidosis are often associated with symptomatic magnesium depletion 3
Diagnosis and Treatment of Hypomagnesemia
- Measurement of fractional excretion of magnesium and urinary calcium-creatinine ratio can help determine the likely cause of hypomagnesemia 2
- Oral magnesium supplements are recommended for asymptomatic patients 2, 3
- Parenteral magnesium should be reserved for symptomatic patients with severe magnesium deficiency (< 1.2 mg/dL) 2
- Intravenous or intramuscular magnesium sulfate can be used for urgent correction of hypomagnesemia 5
- Laboratory tests, such as total serum magnesium measurement, can be used to diagnose hypomagnesemia 6