Neoplasms

Digestive System Diseases

All Conditions

Colorectal Neoplasms

Intestinal Neoplasms

Gastrointestinal Neoplasms

Digestive System Neoplasms

Gastrointestinal Diseases

Colonic Diseases

Intestinal Diseases

Rectal Diseases

Micronutrients

All Drugs and Chemicals

Bone Density Conservation Agents

Vitamins

Vitamin D

Cholecalciferol

Vitamin D3

Calciferol

Participants who have the GG genotype will be assigned to magnesium glycinate

Participants who have the GG genotype will be assigned to placebo group

Participants who have the GA/AA genotype will be assigned to magnesium glycinate

Participants who have the GA/AA genotype will be assigned to placebo group

Oral administration of magnesium glycinate daily for 12 weeks

Magnesium glycinate

Oral administration of identical-appearing placebo daily for 12 weeks

Placebo

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.

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

Effect of Magnesium Treatment on Vitamin D Resistance

25-Hydroxyvitamin D3 was extracted from plasma by liquid extraction and measured by using a novel liquid chromatography-mass spectrometry (LC-MS) method.

25-Hydroxyvitamin D3 was extracted from plasma by liquid extraction, and measured by using a novel liquid chromatography-mass spectrometry (LC-MS) method

24,25-dihydroxyvitamin D3 was extracted from plasma by liquid extraction, and detected by using a novel liquid chromatography-mass spectrometry (LC-MS) method.

1,25-dihydroxyvitamin D3 was extracted from plasma using ALPCO immunoextraction kit following manufacturer's protocols. It was detected by a liquid chromatography-mass spectrometry (LC-MS) method.

1,25-dihydroxyvitamin D2 were extracted from plasma using ALPCO immunoextraction kit following manufacturer's protocols. It was detected by a liquid chromatography-mass spectrometry (LC-MS) method.

Study title	NCT ID	Conditions	Interventions	Eligibility	Organization	Link
Magnesium Treatment on Vitamin D Metabolism in Participants Completed Personalized Prevention of Colorectal Cancer Trial	NCT03265483	Colorectal Canc...	Magnesium glyci... Placebo	40 Years - 85 Years	Vanderbilt University Medical Center
Magnesium Treatment on Vitamin D Metabolism in Participants Completed Personalized Prevention of Colorectal Cancer Trial	NCT03265483	Colorectal Canc...	Magnesium glyci... Placebo	40 Years - 85 Years	Vanderbilt University Medical Center

Spots Global Cancer Trial Database for vitamin d metabolism and synthesis