From the Research
Normal urine magnesium levels typically range from 70 to 120 mg per day (or approximately 3 to 5 mmol per day) in adults on a standard diet. This range can vary slightly depending on dietary intake, as magnesium excretion reflects the balance between absorption and kidney function 1. Urine magnesium levels may be measured as part of an evaluation for magnesium deficiency, kidney stones, or certain metabolic disorders. Factors that can affect urine magnesium include:
- Diet (high magnesium foods like nuts, seeds, and leafy greens)
- Medications (especially diuretics)
- Kidney function
- Hormonal status Low urine magnesium may indicate deficiency or increased reabsorption by the kidneys, while high levels can suggest excessive intake or impaired renal reabsorption. Magnesium homeostasis is primarily regulated by the kidneys, which can increase or decrease excretion based on the body's needs, making urine levels an important indicator of overall magnesium status 2.
The most recent and highest quality study, which is from 2011 2, provides evidence that urine magnesium levels can be an important indicator of magnesium status, and that low levels may be associated with certain metabolic disorders, such as urolithiasis. However, the study also notes that the prevalence of urolithiasis in male patients was 65.8% and 34.2% in female patients, and that serum calcium, phosphorus, and uric acid levels were also significant in the development of urolithiasis.
In terms of the normal range of urine magnesium, the study from 1996 1 provides evidence that the median value for urinary magnesium was 127 mg per 24-hour specimen in healthy control subjects, while the study from 2011 2 notes that the magnesium level in urine was 131.4+/-86.9 in non-stone formers.
Overall, the normal range of urine magnesium is typically considered to be between 70 to 120 mg per day, but this can vary depending on individual factors, such as diet and kidney function 1, 2.