Vitamin A Deficiency Increases the Risk and Severity of Diabetic Retinopathy

Vitamin A inhibits angiogenesis, inflammation and fibrosis, which can benefit the health of patients with type 2 diabetes by reducing their risk of developing diabetic retinopathy. Photo: Jay Haynie, OD. Click image to enlarge. Particular nutrients can have a more profound effect on certain parts of the body compared to others and it has been well documented that vitamin A deficiency is associated with diabetic retinopathy. However, as researchers haven’t conclusively determined its relationship in specific types of diabetes—for instance, type 2—a team from China gathered data to compare vitamin A levels in healthy patients and type 2 diabetes patients, with and without diabetic retinopathy.This comparative study assigned a 2:1 ratio of subjects (1,020 with type 2 diabetes and 470 healthy controls). There were 500 diabetic patients without diabetic retinopathy and 520 patients with ocular involvement. Each participant went through multiple tests, including laboratory studies and serum sampling, to allow the researchers to better understand the relationship between vitamin A deficiency and diabetic retinopathy. Approximately 44% of the study’s population was then diagnosed with deficient vitamin levels (<1.0 μmol/L).In this study, the results showed that vitamin A deficiency was associated with diabetic retinopathy in patients with type 2 diabetes, especially for patients who smoked, had hypertension or had HbA1c levels >7.7%. However, patients with a vitamin A level >1.0 μmol/L had a significantly reduced risk of developing diabetic retinopathy compared to those with a deficiency. The researchers also discovered that lower vitamin levels increased the severity of diabetic retinopathy.“Our finding that higher vitamin A levels decreased the risk of developing diabetic retinopathy can be explained by the mechanism involved in the development of the condition and the mechanism of action for vitamin A,” stated the authors in their paper. “Vitamin A has anti-angiogenesis, anti-inflammation and anti-fibrotic effects, which protect against the onset of DR.”Although the study’s findings offer further insight into the relationship between vitamin A deficiency and diabetic retinopathy, the researchers suggest that more investigations into this correlation should be conducted. They made this inference due to the lack of nutritional data and the exclusion of the duration of type 2 diabetes. Furthermore, the study did not extensively document vitamin A supplementation, with only 5.3% of the subjects adhering to a regimen.“Vitamin A correlates with a high risk of developing diabetic retinopathy in type 2 diabetes patients, more closely in those who are smokers, have hypertension or have an HbA1c level of greater than 7.7 percent,” concluded the authors. “However, the observed association is also likely confounded by glycemic control, metabolic status, and dietary factors, making it difficult to attribute an independent role to vitamin A in diabetic retinopathy pathogenesis.”Click here for the journal source. Zhang MJ, Cheng F. Association between low serum vitamin A level and diabetic retinopathy in patients with type 2 diabetes: A hospital-based study. J Inflamm Res 2025;18:7097-7104.