The effect of magnesium supplementation on vascular calcification in chronic kidney disease—a randomised clinical trial (MAGiCAL-CKD): essential study design and rationale

Randomized, placebo-controlled clinical trial in 250 adults with predialysis chronic kidney disease stage 3b-4. Enrollment was stratified by diabetes status and study site across 10 nephrology centers in Denmark and Norway.

Oral slow-release magnesium hydroxide (Mablet 360 mg) was tested at a daily dose of 30 mmol elemental magnesium, given as 2 tablets per day for 52 weeks, compared with placebo.

This paper presents the trial design and rationale rather than efficacy results. The primary endpoint is the difference in change in coronary artery calcification score from week 0 to week 52 between magnesium and placebo, measured by CT using the Agatston method. Secondary endpoints include cf-PWV, PWA, BMD, mineral metabolism markers, eGFR decline, major adverse cardiovascular events, all-cause and cardiovascular mortality, adverse events, and ESRD. The authors conclude that the study will test whether increasing magnesium uptake can slow vascular calcification progression in predialysis CKD, but coronary artery calcification is a surrogate endpoint and the trial is not powered for cardiovascular events or mortality.

No clinical efficacy results are reported in this design paper. Coronary artery calcification is a surrogate endpoint, and the trial is not powered to assess cardiovascular events or mortality. Per-arm sample sizes and demographic details are not specified in the source packet.