Background: Previous in vitro and in vivo studies have shown that enzymes that synthesize and metabolize vitamin D are magnesium-dependent. Recent observations suggest that magnesium intake significantly interacts with vitamin D on vitamin D status and risk of mortality. According to NHANES, 79% of US adults do not meet the recommended magnesium intake.
Objectives: The aim of this study was to test the hypothesis that magnesium supplementation differentially affects vitamin D metabolism depending on baseline 25-hydroxyvitamin D [25(OH)D] concentration.
Methods: The study included 180 participants aged 40-85 years and was an additional study independently funded by the National Cancer Institute as part of the Personalized Colorectal Cancer Prevention Trial (PPCCT) that enrolled 250 participants. The PPCCT was a double-blind, 2 × 2 factorial randomized controlled trial conducted at Vanderbilt University Medical Center. Both magnesium and placebo doses were determined based on baseline dietary intake. Subjects were randomly assigned to treatments using a permuted block randomization algorithm. Changes in plasma 25-hydroxyvitamin D3 [25(OH)D3], 25-hydroxyvitamin D2 [25(OH)D2], 1,25-dihydroxyvitamin D3, 1,25-dihydroxyvitamin D2, and 24,25-dihydroxyvitamin D3 [24] ,25(OH)2D3] were measured by liquid chromatography-mass spectrometry.
Results: The associations between magnesium treatment and plasma concentrations of 25(OH)D3, 25(OH)D2, and 24,25(OH)2D3 were significantly different depending on baseline 25(OH)D concentrations, and significant interactions persisted. After Bonferroni corrections. Magnesium supplementation increased 25(OH)D3 concentrations when baseline 25(OH)D concentrations approached 30 ng/mL, but decreased them when baseline 25(OH)D was higher (~30 to 50 ng/mL). Magnesium treatment significantly affected 24,25(OH)2D3 concentrations when baseline 25(OH)D concentrations were 50 ng/mL, but not 30 ng/mL. On the other hand, magnesium treatment increased 25(OH)D2 as baseline 25(OH)D increased.
Conclusion: Our results suggest that optimal magnesium status may be important for optimizing 25(OH)D status. This study was registered on clinical.gov as NCT03265483.
Source: https://pubmed.ncbi.nlm.nih.gov/30541089/
