Magnesium Treatment on Vitamin D Metabolism in Participants Completed Personalized Prevention of Colorectal Cancer Trial

Not Applicable

Completed

Conditions: Colorectal Cancer

Registration Number: NCT03265483

Lead Sponsor: Vanderbilt University Medical Center

Brief Summary: One striking observation is that a large portion of the inter-person variation in serum 25-hydroxyvitamin D (25(OH)D) levels is unexplained. In vitro and in vivo studies indicate vitamin D synthesizing and metabolizing enzymes are Mg-dependent. Magnesium (Mg) supplementation substantially reversed the resistance to vitamin D treatment in patients with magnesium-dependent vitamin-D-resistant rickets. The investigators reported in 2013 from observational studies conducted in the general US population that Mg intake significantly interacted with vitamin D intake in affecting vitamin D status as well as interacted with serum 25(OH)D in risk of cardiovascular disease mortality and, maybe, colorectal cancer mortality. The potential interaction between Mg and vitamin D was supported by two subsequent studies, including a Finnish cohort study and a mouse study.

In the parent study (Personalized Prevention of Colorectal Cancer Trial, NCT01105169), the investigators proposed to measure blood concentration of total 25(OH)D as a secondary aim using Elisa approach. However, following the novel finding of Mg-vitamin D interaction published by the investigators in 2013, they submitted a separate grant application to NCI which was funded in 2014. In the new study, the investigators proposed to use a LC-MS approach, which is more accurate and specific than an Elisa method, to measure 5 vitamin D metabolites. This new ancillary study allows the investigators to evaluate whether Mg supplementation differentially affects vitamin D synthesis and metabolism dependent on baseline serum 25(OH)D levels using existing biospecimens collected in our double-blind placebo-controlled randomized chemoprevention trial.

Detailed Description: Not available

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 180

Inclusion Criteria

Participants from our parent study (Personalized Prevention of Colorectal Cancer Trial, NCT#01105169, IRB#100106);
Participants who had completed the above study before the time of the sample selection (October 2015);
Participants consent to store/share samples for future research in colorectal tumors.

Exclusion Criteria

Participants cannot provide their blood samples in the parent study.

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Comparisons of the Changes of Blood 25-Hydroxyvitamin D2 (25(OH)D2) Between Magnesium Treatment and Placebo Arm, Stratified by the Baseline 25-hydroxyvitamin D (25(OH)D) Levels	12 weeks	25(OH)D2 was extracted from plasma by liquid extraction and measured by using a novel liquid chromatography-mass spectrometry (LC-MS) method. The baseline 25(OH)D were measured by: the baseline value of 25(OH)D2 + the baseline value of 25(OH)D3. The changes of 25(OH)D2 were measured as: the post-treatment value of 25(OH)D2 (at Week 12) - the pre-treatment value of 25(OH)D2 (at baseline).
Comparisons of the Changes of Blood 25-Hydroxyvitamin D3 (25(OH)D3) Between Magnesium Treatment and Placebo Arm, Stratified by the Baseline 25-hydroxyvitamin D (25(OH)D) Levels	12 weeks	25(OH)D3 was extracted from plasma by liquid extraction and measured by using a novel liquid chromatography-mass spectrometry (LC-MS) method. The baseline 25(OH)D were measured by: the baseline value of 25(OH)D2 + the baseline value of 25(OH)D3. The changes of 25(OH)D3 were measured as: the post-treatment value of 25(OH)D3 (at Week 12) - the pre-treatment value of 25(OH)D3 (at baseline).
Comparisons of the Changes of Blood 24,25-dihydroxyvitamin D3 (24,25(OH)2D3) Between Magnesium Treatment and Placebo Arm, Stratified by the Baseline 25-hydroxyvitamin D (25(OH)D) Levels	12 weeks	24,25(OH)2D3 was extracted from plasma by liquid extraction and detected by using a novel liquid chromatography-mass spectrometry (LC-MS) method. The baseline 25(OH)D were measured by: the baseline value of 25(OH)D2 + the baseline value of 25(OH)D3. The changes of 24,25(OH)2D3 were measured as: the post-treatment value of 24,25(OH)2D3 (at Week 12) - the pre-treatment value of 24,25(OH)2D3 (at baseline).

Secondary Outcome Measures

Name	Time	Method

Trial Locations

Locations (1): Vanderbilt University Medical Center
🇺🇸
Nashville, Tennessee, United States
Vanderbilt University Medical Center
🇺🇸Nashville, Tennessee, United States