Magnesium plays a foundational role in animal health, yet its importance is often overlooked in companion animal nutrition. In this Real Science Webinar, Stephen Ashmead, Senior Fellow of Research & Development at Balchem, provides a comprehensive look at magnesium as a crucial macromineral and its role in supporting hundreds of biological processes across species.
This session begins by positioning magnesium as a light, alkaline earth element with broad biological significance, essential for over 300 enzymatic reactions, including energy generation in animals and photosynthesis in plants. From there, Ashmead explores how magnesium is absorbed, regulated, and utilized in the body—highlighting the importance of both dietary intake and physiological control mechanisms.
Understanding Magnesium Absorption and Regulation
A key focus of the webinar is how magnesium is absorbed in mammals. While a small portion is taken up through active transport via the TRPM pathway—primarily when dietary magnesium is limited—the majority (80–90%) is absorbed through a paracellular pathway. This non-saturable process allows magnesium to pass between intestinal cells, meaning absorption increases with intake. The kidneys then play a vital role in maintaining balance, filtering excess magnesium while reabsorbing what is needed to keep serum levels stable.
Why Magnesium Matters: Core Physiological Functions
Ashmead categorizes magnesium’s function into three critical areas:
– Energy Production – Magnesium acts as a cofactor in ATP generation, supporting glycolysis and fat metabolism. Without it, cellular energy production cannot function efficiently.
– Structural Support – Roughly half of the body’s magnesium is stored in bone, contributing to skeletal integrity alongside calcium and phosphorus. It also plays a key role in muscle relaxation, helping prevent cramps, tremors, and spasms.
– Neurological and Cardiac Function – Magnesium helps regulate nerve signaling and supports healthy cardiac rhythm by balancing calcium and potassium activity. It also modulates NMDA receptors, which may contribute to calming effects in certain animals.
Formulation Considerations and Bioavailability
While clinical magnesium deficiency is rare in animals fed complete diets, optimizing magnesium intake can still deliver performance and health benefits—especially in functional treats and supplements.
A central takeaway from the webinar is that not all magnesium sources are equal:
– Inorganic sources (e.g., magnesium oxide) provide high mineral content but have poor solubility and absorption.
– Soluble salts (e.g., magnesium sulfate) improve solubility but may cause gastrointestinal issues.
– Chelated magnesium sources (e.g., magnesium glycinate) offer superior bioavailability and tolerability while protecting the mineral from antagonists like phytates.
Special considerations are also required when formulating for cats. Diets that raise urinary pH above 6.4 can increase the risk of struvite crystal formation, making source selection and formulation strategy especially important in feline products.
Key Takeaways from the Webinar
– Magnesium absorption is primarily driven by dietary intake through a non-saturable paracellular pathway, with the kidneys maintaining tight homeostatic control.
– It is essential for hundreds of biological processes, including energy production, muscle function, and nerve signaling.
– The form of magnesium significantly impacts bioavailability, making chelated sources a preferred choice in many applications.
– Feline nutrition requires careful formulation to avoid unintended urinary health risks.
Audience Q&A Highlights
During the session, attendees explored several practical and technical questions, including:
– The importance of magnesium balance with potassium for nerve conduction
– Challenges in measuring magnesium status due to tight biological regulation
– The role of red blood cell magnesium and urinary excretion in assessing bioavailability
– Considerations when transitioning from inorganic to chelated mineral sources
– Why magnesium is often overlooked due to the lack of clear clinical deficiency markers
