Low Magnesium Levels Linked to DR Risk

In a meta-analysis of 17 studies including 1,100 patients with diabetic retinopathy and 1,132 diabetic controls, serum magnesium levels were significantly lower in DR. Levels were further reduced in proliferative vs. nonproliferative DR, supporting magnesium as a potential biomarker for disease severity and risk stratification. Photo: Qunol. April 17, 2026. Click image to enlarge. Diabetic retinopathy (DR) affects approximately 80% of patients with diabetes, and is one of the leading causes of preventable blindness. Magnesium, an intracellular cation implicated in metabolism and insulin signaling, may have an association with insulin resistance, endothelial dysfunction and increased oxidative stress in the background of type 2 diabetes. Small observational studies have reported a link between low magnesium and diabetic retinopathy risk; however, a more robust study recently published in the journal Nutrients further supports this connection, suggesting that magnesium level may be a widely accessible and inexpensive biomarker for risk stratification in DR. The meta-analysis included a total of 17 studies collected from a literature search, all of which investigated magnesium levels in patients with type 2 diabetes with and without DR. This ultimately comprised 1,100 patients with DR and 1,132 diabetic controls without DR. A majority of the studies were conducted in Asia (14) and India (11), with the remainder conducted in Pakistan (1), Bangladesh (1), Iraq (1), Africa (2) and Turkey (1). According to their results, the random-effects model indicated significantly lower magnesium levels in patients with DR compared to diabetic controls. The standardized mean deviation (SMD) between the groups was -1.19; SMD was used  to pool data from disparate sources. When comparing magnesium levels in cases with proliferative DR to cases with nonproliferative DR, levels were found significantly lower in cases with proliferative disease (SMD = -1.41). The researchers also conducted subgroup analyses to identify possible sources of heterogeneity. The results showed significantly lower magnesium levels among patients with DR in both groups. The Asian subgroup showed an SMD of -1.34, while the non-Asian subgroup showed SMD of -0.41.The causes of low magnesium levels in diabetic patients may result from inadequate dietary intake or increased urinary magnesium loss, both of which are common in diabetes, wrote the authors in their paper. “Clinical trials investigating magnesium supplementation in diabetic populations have demonstrated beneficial outcomes in terms of lowering oxidative stress markers, improving insulin resistance indices, lowering fasting glucose and glycated hemoglobin levels,” they continued. “Collectively, these beneficial effects of magnesium support the view that magnesium is a potentially modifiable factor for diabetic retinopathy. However, to date, no clinical trial has directly evaluated magnesium supplementation for the prevention or progression of diabetic retinopathy.”The authors referenced other research on magnesium supplementation, which shows some reduction in the progression or prevention of DR, including a clinical trial meta-analysis that showed a dose-response effect of magnesium supplementation on the reduction in both fasting blood glucose and glycated hemoglobin. “These premises indicate a beneficial effect of magnesium supplementation on improving glycemic control, intracellular stress levels and modulating inflammation,” the authors wrote in the journal. “Hence, we can deduce that magnesium can, indirectly, slow or prevent the progression of diabetic retinopathy.”In terms of possible limitations, they noted that dietary magnesium intake was not assessed in most studies, neither were renal function and urinary magnesium. All included studies were observation, precluding causal inference, and finally, temporal relationships cannot be excluded, they wrote.“The principal finding of this study is that patients with diabetic retinopathy exhibit significantly lower circulating magnesium levels compared with diabetic patients without retinopathy,” they concluded. Eye doctors as well as primary care physicians and endocrinologists “are urged to consider assessing and correcting magnesium levels in patients with diabetes,” the researchers advised, and pointed out that “randomized controlled trials are needed to determine the impact of magnesium supplementation on the prevention or slowing the progression of diabetic retinopathy.”Click here for the journal source. Kubbara EA, Hamdan SZ, Hajali TA, Rezk MY, Hamdan HZ. Association between levels of magnesium and diabetic retinopathy in diabetic patients with type 2 diabetes mellitus: An updated systematic review and meta-analysis. Nutrients. April 5, 2026. [Epub ahead of print.] This article was developed by the editorial staff in conjunction with experts in the field. In the process, AI may have been among the editorial tools used to meet the goals of human editors, who approved all content.