Timing of magnesium supplementation in patients with nephrolithiasis: A randomized controlled trial.
Level 2 - randomized trial
Individual randomized controlled pilot trial
PubMed 39913253 · doi:10.5414/CN111168
What was done
A single-institution, prospective, randomized controlled pilot trial evaluated the effect of magnesium supplementation timing in patients with a history of calcium oxalate stones and isolated hyperoxaluria. Eight patients were provided a controlled diet and randomized (1:1, n=4 per arm) to take magnesium supplements either with meals or while fasting for 7 days. Changes in 24-hour urinary biochemistry (oxalate, magnesium, citrate) were assessed from pre- to post-intervention.
What was found
Patients taking magnesium with meals had a median decrease in urinary oxalate of 17.8 mg/d, an increase in urinary magnesium of 33.6 mg/d, and an increase in urinary citrate of 134.8 mg/d. Patients taking magnesium while fasting had an average decrease in urinary oxalate of 8.5 mg/d, an increase in urinary magnesium of 21.8 mg/d, and an increase in urinary citrate of 116.6 mg/d. The abstract did not report p-values or confidence intervals.
Why it matters
Co-administering magnesium with meals may optimize intestinal binding of oxalate and improve urinary lithogenic profiles compared to fasting administration for stone prevention.
Limits
The sample size is extremely small (n = 8 total, 4 per group), the study duration was very brief (7 days), and statistical significance (p-values or confidence intervals) was not reported in the abstract. Clinical stone recurrence outcomes were not assessed.
Cited by
- supports Adequate magnesium intake, such as magnesium citrate and magnesium glycinate, helps prevent kidney stones.