New clinical evidence indicates that a widely used supplement may alter gut microbes involved in vitamin D biology and colorectal cancer processes.
Researchers at Vanderbilt University Medical Center have shown in a precision-focused clinical trial that taking a magnesium supplement can increase certain gut bacteria in people. These bacteria are known to produce vitamin D and to play a role in limiting the development of colorectal cancer.
The effect was seen mainly in women. The researchers suggest this difference may be linked to estrogen, which can influence how magnesium moves from the bloodstream into cells.
Genetics determine who benefits most
To understand who benefits most, the team examined gut microbiome data and colonoscopy findings from participants grouped according to their TRPM7 genotype. This gene is important for controlling how the body absorbs magnesium and calcium.
In earlier work from the same randomized trial, the investigators found that magnesium boosts vitamin D production and raises vitamin D levels in the blood. The new results indicate that magnesium also promotes vitamin D production directly within the gut. This locally produced vitamin D does not enter the bloodstream and instead acts where it is made.
These results from the Personalized Prevention of Colorectal Cancer Trial were recently published in The American Journal of Clinical Nutrition.
Gut microbes link magnesium to cancer risk
“Our previous study showed magnesium supplementation increased blood levels of vitamin D when vitamin D levels were low,” said Qi Dai, MD, PhD, professor of Medicine. “The current study reveals that magnesium supplementation also increases the gut microbes, which have been shown to synthesize vitamin D in the gut without sunlight and locally inhibit colorectal cancer development.”
The participants were divided into two groups: one that received the magnesium supplement and another that received a placebo. Their gut microbiome was analyzed from stools, rectal swabs, and rectal tissues. Among participants with adequate TRPM7 function, the magnesium supplement increased Carnobacterium maltaromaticum and Faecalibacterium prausnitzii, which were previously found to work synergistically to increase vitamin D and decrease colorectal carcinogenesis. Among those with inadequate TRPM7 function, the magnesium supplement reduced the abundance of F. prausnitzii in rectal mucosa.
From microbiome shifts to prevention strategies
Among 236 participants who all had a history of colorectal polyps, 124 underwent colonoscopies after completing the trial with a 3.5-year median follow-up time. A higher abundance of F. prausnitzii in rectal mucosa was associated with an almost threefold increase in developing additional polyps.
The findings suggest that magnesium supplementation treatment may decrease colorectal cancer risk in individuals with inadequate TRPM7 function. All together, these findings provide new insights into the interplays between nutrition and gut microbiome contributing to colorectal carcinogenesis and establish the foundation for a precision-based strategy for prevention of colorectal cancer in high-risk populations.
Reference: “Magnesium treatment increases gut microbiome synthesizing vitamin D and inhibiting colorectal cancer: results from a double-blind precision-based randomized placebo-controlled trial” by Elizabeth Sun, Xiangzhu Zhu, Reid M. Ness, M. Andrea Azcarate-Peril, Martha J. Shrubsole, and Qi Dai, November 2025, The American Journal of Clinical Nutrition.
DOI: 10.1016/j.ajcnut.2025.09.011
The researchers received support from the National Cancer Institute (R01 DK110166, R01 CA149633 and R03 CA 189455) and the Vanderbilt-Ingram Cancer Center Endowment Fund. Dai and Martha Shrubsole, PhD, Ingram Professor of Cancer Research and research professor of Medicine, are principal investigators of the grant that funded the microbiome research from the National Institute of Diabetes and Digestive and Kidney Diseases (DK110116).
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10 Comments
I take 400mg magnesium and 50 mg B3 at bedtime yet I have gut issues and anal cancer cells. I’ve had anal surgery twice at Concord hospital, New Hampshire. I feel nauseous all the time and my stomach floats whether I eat or not. What else should I do.
Check out Chris Beat Cancer. There is a wealth of information there.
Synthetic drugs will never help you ! What are the actual ingredients and ricks ! Since the medical has failed you ! Start your lawsuit now the medical manufacturer will get you a bigger payout ! As for your synthetic drugs ! Get a better doctor maybe out of America. Take care . I love you 😘
You should be evaluated for mast cell activation disorder and maybe try cromolyn
If possible, identify the cause. Then eliminate the cause, if possible. These two steps are critically important and too often not completed. This is important when treating any and all medical problems.
I’ve dealt with similar issues. I’ve been told to increase fiber in my diet. The colorless, flavorless fiber powder helps tremendously. I add it to almost everything. My stomach no longer feels sloshy and unsettled.
What form of magnesium were the participants given?
Great question! This article is so lackluster. Here’s additional information for you and others:
Based on the clinical study referenced in the article, the type of magnesium used was magnesium glycinate.
The article discusses findings from the “Personalized Prevention of Colorectal Cancer Trial” (PPCCT), conducted by researchers at Vanderbilt University Medical Center. In this randomized controlled trial (registered as NCT01105169), participants were administered magnesium glycinate to study its effects on gut bacteria, vitamin D synthesis, and colorectal cancer risk.
Key details from the study:
* Supplement Used: Magnesium glycinate.
* Mechanism: The study found that magnesium supplementation increased the abundance of specific gut bacteria (Carnobacterium maltaromaticum and Faecalibacterium prausnitzii) that synthesize vitamin D. This locally produced vitamin D helps inhibit the development of colorectal cancer cells.
* Trial Name: Personalized Prevention of Colorectal Cancer Trial (PPCCT).
* Publication: The results were published in The American Journal of Clinical Nutrition (November 2025).
Synthetic drug has death written all over them ! The medical professions know what it was going to do to us patients and never changed too the name Brands too see if it would make us better ! Scientists have all the answers but pharmaceutical paid out in the trillions of dollars not too tell a soul ! Colleges have to test drugs just to check the results if we die off in seconds hours days weeks months years ! LUKE 6:31 ! Now that we have completely included GOD LETS START THE TRUTH !
I wonder why they didn’t simply suggest that people take vitamin D supplements….?