Effect of magnesium oxide or citrate supplements on metabolic risk factors in kidney stone formers with idiopathic hyperoxaluria: a randomized clinical trial.
Level 2 - randomized trial
Randomized, double-blind, placebo-controlled clinical trial
PubMed 39077820 · doi:10.1684/mrh.2024.0524
What was done
In a randomized, double-blind, placebo-controlled trial, 90 calcium stone formers with idiopathic hyperoxaluria were recruited from a tertiary stone prevention clinic. Participants were randomly assigned to three groups: 120 mg magnesium oxide (MgO), 120 mg magnesium citrate (MgCit), or placebo, taken three times per day with meals for eight weeks. Dietary factors were controlled with 24-hour food recalls. Analyses of 24-hour urine collections were performed at baseline and after eight weeks in the 76 patients who completed the study. Outcomes were changes in 24-hour urinary oxalate, magnesium, citrate, and calcium oxalate supersaturation.
What was found
After eight weeks, 24-hour urinary oxalate excretion decreased by -8.13 +- 16.45 in the MgO group and -16.99 +- 18.02 in the MgCit group compared to placebo. Decreases in 24-hour urinary oxalate and calcium oxalate supersaturation reached statistical significance versus placebo only in the MgCit group (p=0.011 and p=0.010, respectively). An increasing trend for 24-hour urine magnesium and citrate excretion was observed without significant differences between groups. MgCit had a significantly greater inhibitory effect on urinary oxalate in patients with normal baseline urine magnesium levels (p=0.021).
Why it matters
Oral magnesium citrate significantly lowers urinary oxalate excretion and calcium oxalate supersaturation in idiopathic hyperoxaluric stone formers, performing better than magnesium oxide.
Limits
The sample size is small with 76 completed patients and 14 dropouts from 90 recruited. Follow-up was limited to eight weeks, clinical stone recurrence events were not assessed, and measurement units for urine oxalate changes were not stated in the abstract.
Cited by
- partial Adequate magnesium intake, such as magnesium citrate and magnesium glycinate, helps prevent kidney stones.