From the Guidelines
A normal level of magnesium (Mg) is between 1.3 to 2.2 mEq/L.
Normal Magnesium Levels
- The normal range for serum magnesium concentration is 1.3 to 2.2 mEq/L 1
- Levels below 1.3 mEq/L are considered hypomagnesemia, while levels above 2.2 mEq/L are considered hypermagnesemia 1
- It's worth noting that magnesium deficiency is common, and magnesium has been associated with benefits in treating certain cardiac conditions, such as Torsades de Pointes (TdP) 1
Clinical Considerations
- Hypomagnesemia can result from decreased absorption or increased loss of magnesium, and can be induced by certain medications, such as diuretics, or conditions like malnourishment 1
- Magnesium toxicity is less common, but can occur in patients with renal dysfunction or as an iatrogenic overdose, particularly in pregnant women receiving magnesium for preterm labor 1
From the Research
Normal Magnesium Levels
The normal level of magnesium (Mg) in the blood is a topic of discussion among researchers. According to various studies, the normal range for serum magnesium concentration is:
- 0.75 to 0.95 mmol/L (1.82 to 2.31 mg/dL) 2, 3
- However, some studies suggest that a lower limit of 0.85 mmol/L (2.07 mg/dL) should be used to define normal magnesium levels, as values below this may be associated with increased health risks 4, 2, 5
Factors Affecting Magnesium Levels
Several factors can affect magnesium levels, including:
- Dietary intake: a decrease in magnesium intake over the past century has led to chronic latent magnesium deficiency in many individuals 4
- Kidney function: the kidney plays a crucial role in regulating magnesium levels, and impaired kidney function can lead to hypermagnesemia or hypomagnesemia 3
- Age: normal serum magnesium ranges are similar across all ages 3
Diagnosis of Magnesium Deficiency
Diagnosing magnesium deficiency can be challenging, as serum magnesium levels may not always reflect the body's magnesium status. According to some studies:
- A low serum magnesium level is a definite sign of magnesium deficiency, but values within the reference range do not rule out deficiencies 2
- The use of a lower reference limit of 0.85 mmol/L can help prevent the inclusion of patients with chronic latent magnesium deficit (CLMD) in the normal range 5
- The current reference ranges for serum magnesium may underestimate the diagnosis of hypomagnesemia, highlighting the need for standardization 5, 6