Magnesium Supplementation Shows Promise as Adjunct Therapy in Type 2 Diabetes, suggests research

A new study published in the journal of Frontiers in Endocrinology found that magnesium oxide supplementation improved magnesium status and showed favorable trends in glycemic control without safety concerns, although the median reduction in glycated hemoglobin (HbA1c) was not statistically significant. These findings suggest that magnesium supplementation may be a safe adjunct to long-term management of type 2 diabetes mellitus (T2DM), particularly in selected patient subgroups, while acknowledging the study's limitations.

This trial enrolled 247 adults with T2DM, all of whom had HbA1c levels of at least 7.0% and adequate kidney function. Participants were randomly assigned to receive either 500 mg of magnesium oxide, providing 302 mg of elemental magnesium, or a matching placebo over a 12-month period. This research evaluated biochemical and clinical outcomes at baseline and during three follow-up visits using both intention-to-treat and per-protocol analyses.

The study population had a median age of 58 years and had been living with diabetes for a median of 16 years. At the start of the trial, approximately 7–8% of participants were found to have hypomagnesemia based on ionized and total magnesium measurements.

Despite the reduction in HbA1c not reach statistical significance, the magnesium group experienced a greater median decline in HbA1c than the placebo group (-0.30% versus -0.05%). More notably, 14% of participants receiving magnesium achieved the recommended HbA1c target of below 7%, when compared to only 6% in the placebo group, representing a statistically significant improvement.

Also, magnesium supplementation significantly lowered fasting blood glucose levels in a subgroup of participants. The greatest benefits were observed among individuals who had low magnesium levels at baseline, where HbA1c declined by 0.60% when compared to a 0.25% increase in the placebo group. Participants with a diabetes duration of 15 years or less also demonstrated more favorable improvements in glycemic control than those receiving placebo.

Also, magnesium supplementation did not significantly influence other metabolic markers or clinical outcomes. Importantly, no increase in adverse drug reactions was reported, reinforcing the safety profile of long-term magnesium oxide supplementation. Overall, magnesium supplementation effectively improved magnesium status and showed favorable trends toward better glycemic control, in selected patient subgroups. 

Reference: 

Al-Maqbali, J. S., Al Alawi, A. M., Osman, A., Al-Farqani, A., Kumar, S., Al Futisi, A., Al-Mamari, A., Al-Zakwani, I., & Al Za'abi, M. (2026). The effect of oral magnesium supplementation on glycemic control and metabolic parameters in type 2 diabetes mellitus: a double-blind randomized controlled trial. Frontiers in Endocrinology, 17, 1883483. https://doi.org/10.3389/fendo.2026.1883483