Magnesium Deficiency and Cancer: A Silent Risk Factor You Can Fix Today

Learn which cancers are linked to low magnesium, how it impacts pain, sleep, immunity, and the form I trust most.

Researched and written by Keith Bishop, Clinical Nutritionist, Cancer Coach, Retired Pharmacist, and Founder of Prevail Over Cancer

Flashier nutrients in discussions about cancer often overshadow magnesium, yet it plays a foundational role in cellular health, immune regulation, and metabolic balance. Emerging research reveals that magnesium deficiency may not only increase cancer risk but also impair recovery, worsen treatment side effects, and disrupt quality of life. Let’s explore the science behind magnesium’s anticancer benefits—and why it deserves a central place in integrative oncology.

Magnesium’s Role in Cancer Biology

Magnesium is a cofactor in over 600 enzymatic reactions, including DNA repair, RNA synthesis, and ATP production. It regulates oxidative stress, inflammation, and calcium signaling—all of which are tightly linked to cancer development and progression.

• Magnesium supports genomic stability by activating DNA polymerases and repair enzymes. Deficiency leads to an increase in strand breaks and chromosomal aberrations.[i]
• It modulates key oncogenic pathways like PI3K/Akt and MAPK, which are often dysregulated in malignancies.
• Magnesium-dependent ion channels (e.g., TRPM7) influence tumor cell migration and invasion, especially in breast and pancreatic cancers.

Cancers Linked to Magnesium Deficiency

Multiple studies have identified specific cancers with elevated risk due to low magnesium intake or serum levels:

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Magnesium’s Supportive Role in Cancer Care

Beyond prevention, magnesium helps manage common symptoms and side effects during treatment:

🧠 Pain Management

• Magnesium modulates NMDA receptors and calcium channels, reducing neuropathic and inflammatory pain.
• It may enhance opioid efficacy and reduce tolerance development.

💩 Constipation

• Magnesium citrate and oxide act as osmotic laxatives, drawing water into the colon to ease bowel movements as they are not as well absorbed as other forms. But high doses of any magnesium will have similar effects. If stools become too loose, decrease the dose.

😰 Anxiety & Sleep

• Magnesium glycinate supports GABAergic activity, promoting calm and improving sleep quality.
• Deficiency is linked to elevated cortisol and disrupted circadian rhythms.

⚡ Energy & Fatigue

• Magnesium is essential for mitochondrial ATP production and glycolysis, directly impacting cellular energy.
• Supplementation may reduce cancer-related fatigue and improve vitality.

🍬 Blood Glucose Control

• Magnesium improves insulin sensitivity and glucose uptake, reducing risk of metabolic syndrome and treatment-induced hyperglycemia.

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💊 Why I Prefer Magnesium Glycinate

Among the many forms available, magnesium glycinate is my preferred choice. It’s:

• Highly bioavailable
• Gentle on the gut (less likely to cause diarrhea)
• Effective for calming the nervous system and supporting sleep

For patients undergoing cancer treatment, this form offers a well-tolerated option that supports both physical and emotional resilience.

My wife, Janay, and I take either one of the following magnesium glycinate twice a day:

• Magnesium Glycinate Capsules by Douglas
• Magnesium by Designs for Health.

📚 References

1. MDPI Nutrients: Magnesium in Cancer Therapy
2. Biology Insights: Magnesium & Tumor Biology
3. American Journal of Clinical Nutrition – Colorectal Cancer
4. Cancer Therapy Advisor – Magnesium & CRC Risk
5. Nature Scientific Reports – Pancreatic Cancer Risk
6. Journal of Health, Population and Nutrition – Immune Regulation
7. SAGE Journals – Magnesium & Pain
8. Mayo Clinic Press – Magnesium Supplement Types
9. Drugs.com – Magnesium & Sleep
10. NIH Office of Dietary Supplements – Magnesium Fact Sheet
11. BeatCancer.org – Magnesium Deficiency & Cancer
12. Magnesium & Metabolic Health – NIH Review

[i] Sambataro D, Scandurra G, Scarpello L, Gebbia V, Dominguez LJ, Valerio MR. A Practical Narrative Review on the Role of Magnesium in Cancer Therapy. Nutrients. 2025; 17(14):2272. https://doi.org/10.3390/nu17142272