By Dr. Liji Thomas, MD Reviewed by Lauren Hardaker Feb 13 2026 A carefully controlled trial finds that magnesium can lower fasting glucose in older adults with magnesium deficiency, but stopping diabetes progression may require more than correcting a single mineral. Study: Oral magnesium supplementation improves glycemic control in older Chinese adults with pre-diabetes and hypomagnesemia: a randomized controlled trial . Image credit: Pixel-Shot/Shutterstock.com Prediabetes is a state marked by