{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,8]],"date-time":"2026-07-08T18:03:57Z","timestamp":1783533837654,"version":"3.55.0"},"reference-count":48,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2021,12,25]],"date-time":"2021-12-25T00:00:00Z","timestamp":1640390400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Novartis (Spain)","award":["1"],"award-info":[{"award-number":["1"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nutrients"],"abstract":"<jats:p>Aim: Results from meta-analyses point to an association between vitamin D deficiency and the onset of diabetic retinopathy (DR). The objectives of the present study were to evaluate the association of vitamin D for the development of DR and to determine the levels of vitamin D associated with a greater risk of DR. Methods: Between November 2013 and February 2015, we performed a case-control study based on a sample of patients with diabetes in Spain. The study population comprised all patients who had at least one evaluable electroretinogram and recorded levels of 25(OH)D. We collected a series of analytical data: 25(OH)D, 1,25(OH)2D, iPTH, calcium, albumin, and HbA1c. Glycemic control was evaluated on the basis of the mean HbA1c values for the period 2009\u20132014. A logistic regression analysis was performed to identify the variables associated with DR. Results: The final study sample comprised 385 patients, of which 30 (7.8%) had DR. Significant differences were found between patients with and without DR for age (69.54 vs. 73.43), HbA1c (6.68% vs. 7.29%), years since diagnosis of diabetes (10.9 vs. 14.17), level of 25(OH)D (20.80 vs. 15.50 ng\/mL), level of 1,25(OH)2D (35.0 vs. 24.5 pg\/mL), treatment with insulin (14.9% vs. 56.7%), hypertension (77.7% vs. 100%), cardiovascular events (33.2% vs. 53.3%), and kidney failure (22.0% vs. 43.3%). In the multivariate analysis, the factors identified as independent risk factors for DR were treatment of diabetes (p = 0.001) and 25(OH)D (p = 0.025). The high risk of DR in patients receiving insulin (OR 17.01) was also noteworthy. Conclusions: Levels of 25(OH)D and treatment of diabetes were significantly associated with DR after adjusting for other risk factors. Combined levels of 25(OH)D &lt; 16 ng\/mL and levels of 1,25(OH)2D &lt; 29 pg\/mL are the variables that best predict the risk of having DR with respect to vitamin D deficiency. The risk factor with the strongest association was the treatment of type 2 diabetes mellitus. This was particularly true for patients receiving insulin, who had a greater risk of DR than those receiving insulin analogues. However, further studies are necessary before a causal relationship can be established.<\/jats:p>","DOI":"10.3390\/nu14010084","type":"journal-article","created":{"date-parts":[[2021,12,27]],"date-time":"2021-12-27T01:06:54Z","timestamp":1640567214000},"page":"84","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":25,"title":["Vitamin D Deficiency Is Significantly Associated with Retinopathy in Type 2 Diabetes Mellitus: A Case-Control Study"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1745-6333","authenticated-orcid":false,"given":"Jos\u00e9 M.","family":"Castillo-Ot\u00ed","sequence":"first","affiliation":[{"name":"Unidad Vigilancia Epidemiol\u00f3gica e Intervenci\u00f3n, 39120 Liencres, Spain"},{"name":"Grupo de Investigaci\u00f3n Salud Comunitaria IDIVAL, Primary Care Department, 39007 Santander, Spain"},{"name":"Facultad de Enfermer\u00eda, Universidad de Cantabria, 39008 Santander, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ana I.","family":"Galv\u00e1n-Manso","sequence":"additional","affiliation":[{"name":"Centro de Salud La Marina, 39009 Santander, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mar\u00eda R.","family":"Callejas-Herrero","sequence":"additional","affiliation":[{"name":"Centro de Salud La Marina, 39009 Santander, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lu\u00eds A.","family":"Vara-Gonz\u00e1lez","sequence":"additional","affiliation":[{"name":"Centro de Salud La Marina, 39009 Santander, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fernando","family":"Salas-Herrera","sequence":"additional","affiliation":[{"name":"Centro de Salud La Marina, 39009 Santander, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1387-2655","authenticated-orcid":false,"given":"Pedro","family":"Mu\u00f1oz-Cacho","sequence":"additional","affiliation":[{"name":"Grupo de Investigaci\u00f3n Salud Comunitaria IDIVAL, Primary Care Department, 39007 Santander, Spain"},{"name":"Unidad Docente de Medicina Familiar y Comunitaria, 39011 Santander, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,12,25]]},"reference":[{"key":"ref_1","first-page":"e339","article-title":"Causes of visi\u00f3n loss worldwide","volume":"1","author":"Bourne","year":"2013","journal-title":"Syst. 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