Latest article: The magnesium-gut connection: Essential considerations for healthcare professionals

Article description 

This article examines the essential role of magnesium in gut physiology, highlighting its influence on motility, barrier integrity, energy production, and the microbiome. It explores how common medications, particularly PPIs and diuretics, may contribute to deficiency and why serum magnesium testing may not always be reliable. The article also outlines preferred magnesium supplementation strategies to support gastrointestinal and systemic health.

Author: Mick Alexander - B.Pharm, BHSc (Naturopathy)

Mick Alexander is an integrative pharmacist, naturopath, author, pharmacy educator, and industry presenter who embraces the benefits of combining natural supplements with conventional medicines. He is an Independent expert contributor for fx Medicine, BioCeuticals education platform. 

Reviewer: Brett Friedman - MSc (Med), ADNM

Brett Friedman is a qualified nutritional medicine practitioner and scientist with a master’s degree in medicine. He is a Senior Practitioner Learning Designer at BioCeuticals and fx Medicine. He was involved in reviewing this article. 

Learning objectives 

• Describe the role of magnesium in gut physiology.
• Evaluate clinical signs and symptoms associated with magnesium deficiency and identify high‑risk patients.
• Differentiate between magnesium supplement formulations based on bioavailability and gastrointestinal tolerability.
• Describe magnesium’s influence on gut microbiome composition and implications for clinical outcomes.
• Provide patient counselling on drug interactions affecting magnesium absorption.

Competency standards 1.1, 1.5, 3.1, 3.2, 3.5, 3.6, 5.3

To complete your Pharmacy CPD credits, please see the link at the end of the article.

Accreditation number: PSAX26003

Accreditation statement: This activity has been accredited for 0.75 hours of Group 2 CPD (or 1.5 CPD credits) on successful completion of relevant assessment activities.

Magnesium is the fourth most abundant cation in the human body and serves as a cofactor for over 600 enzymatic reactions, including those essential for gastrointestinal function.¹ Despite its critical importance, sub-clinical magnesium deficiency affects an estimated 10-30 percent of the general population, with higher prevalence in specific patient groups.²

The relationship between magnesium and gut health extends beyond simple muscle contraction. Emerging evidence suggests dietary deficiency could induce inflammation in rat and human intestines and the resulting inflammation could impair intestinal structural integrity.³ Furthermore, numerous commonly prescribed medications can deplete magnesium stores, creating a cascade of gastrointestinal symptoms that many patients, and very occasionally prescribers, may not attribute to a deficiency.

THE CRITICAL ROLE OF MAGNESIUM IN GUT PHYSIOLOGY

Magnesium's influence on gastrointestinal function operates through multiple complementary mechanisms. At the cellular level, magnesium acts as a natural calcium antagonist,⁴ regulating smooth muscle contraction throughout the gastrointestinal tract. This calcium-magnesium balance directly influences peristaltic activity, with adequate magnesium counterbalancing calcium’s contractility.⁴

In the colon, magnesium exerts an osmotic effect, drawing water into the intestinal lumen and softening stool consistency - the mechanism underlying its well-established laxative properties.⁵ However, magnesium's role extends far beyond simple stool softening. It is essential for adenosine triphosphate (ATP) production, the primary energy currency required for all active transport processes across intestinal epithelial cells.⁶