{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,31]],"date-time":"2026-10-31T15:26:02Z","timestamp":1793460362238,"version":"4.5.0"},"reference-count":45,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2021,8,19]],"date-time":"2021-08-19T00:00:00Z","timestamp":1629331200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Endocrinol."],"abstract":"<jats:p>Vitamin D deficiency could play an important role in the pathogenesis of type 2 diabetes mellitus (T2DM) as it may alter several crucial processes in the development of diabetes and its complications, such as pancreatic insulin secretion, peripheral insulin resistance, persistence of systemic \u201esterile\u201d inflammation and immune activation. Vitamin D may also have an antioxidant effect through the inhibition of free radicals generation. The reported study was designed with eligible consecutively recruited patients with T2DM on standard metformin therapy (n=130), randomized in 1:1 ratio, considered to have undergone Vitamin D supplementation according to the guidelines proposed by the Endocrine Society, or to have continued with metformin only. The potential benefit was monitored through the influence on glycemia level, glycated haemoglobin (HbA1c), insulin resistance index (calculated as homeostatic model assessment; HOMA-IR), Castelli Risk Index I and Tryglicerides\/Thiobarbituric acid<jats:italic>-<\/jats:italic>reactive substances (TG\/TBARS) Index in a 6-month follow up period. Our study indicates that oral daily doses of vitamin D improve HbA1c levels over the 3-month and 6-month period, followed by a significant decrease in advanced oxidation protein products levels over the 3-month period when higher vitamin D doses are given. The effect of vitamin D on HOMA-IR index, malondialdehyde levels and TG\/TBARS index was not statistically significant. Further investigation should consider defining the doses of vitamin D in patients with T2DM which may attenuate the oxidative stress risk, the risk of metabolic syndrome and the risk of related cardiovascular events.<\/jats:p>","DOI":"10.3389\/fendo.2021.610893","type":"journal-article","created":{"date-parts":[[2021,8,19]],"date-time":"2021-08-19T15:05:16Z","timestamp":1629385516000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":112,"title":["The Effects of Vitamin D Supplementation on Metabolic and Oxidative Stress Markers in Patients With Type 2 Diabetes: A 6-Month Follow Up Randomized Controlled Study"],"prefix":"10.3389","volume":"12","author":[{"given":"Milena","family":"Cojic","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Radivoj","family":"Kocic","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aleksandra","family":"Klisic","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gordana","family":"Kocic","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2021,8,19]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"1","DOI":"10.2478\/v10011-012-0025-y","article-title":"The D-Lightful Vitamin D for Health","volume":"32","author":"Holick","year":"2013","journal-title":"J Med Biochem"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMra070553","article-title":"Vitamin D Deficiency","volume":"357","author":"Holick","year":"2007","journal-title":"N Engl J Med"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.2337\/diaspect.24.2.113","article-title":"Vitamin D and Diabetes","volume":"24","author":"Martin","year":"2011","journal-title":"Diabetes Spectr"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1093\/ajcn\/87.4.1080S","article-title":"Vitamin D Deficiency: A Worldwide Problem With Health Consequences","volume":"87","author":"Holick","year":"2008","journal-title":"Am J Clin Nutr"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.5633\/amm.2019.0116","article-title":"The Role of Vitamin D in Treating Patients With Type 2 Diabetes Mellitus","volume":"58","author":"Coji\u0107","year":"2019","journal-title":"Acta Med Median"},{"key":"B6","doi-asserted-by":"publisher","first-page":"22","DOI":"10.4103\/1735-1995.200278","article-title":"Role of Vitamin D on Glycemic Control and Oxidative Stress in Type 2 Diabetes Mellitus","volume":"22","author":"Saif-Elnasr","year":"2017","journal-title":"J Res Med Sci"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.1210\/jc.2017-01024","article-title":"The Effect of Improved Serum 25-Hydroxyvitamin D Status on Glycemic Control in Diabetic Patients: A Meta-Analysis","volume":"102","author":"Mirhosseini","year":"2017","journal-title":"J Clin Endocrinol Metab"},{"key":"B8","doi-asserted-by":"publisher","DOI":"10.1210\/jc.2007-0298","article-title":"The Role of Vitamin D and Calcium in Type 2 Diabetes: A Systematic Review and Meta-Analysis","volume":"92","author":"Pittas","year":"2007","journal-title":"J Clin Endocrinol Metab"},{"key":"B9","doi-asserted-by":"publisher","DOI":"10.1111\/j.1464-5491.2012.03672.x","article-title":"Effect of Vitamin D Supplementation on Glycaemic Control and Insulin Resistance: A Systematic Review and Meta-Analysis","volume":"29","author":"George","year":"2012","journal-title":"Diabetes Med"},{"key":"B10","doi-asserted-by":"publisher","DOI":"10.1210\/jc.2014-2136","article-title":"Effect of Vitamin D3 Supplementation on Improving Glucose Homeostasis and Preventing Diabetes: A Systematic Review and Meta-Analysis","volume":"99","author":"Seida","year":"2014","journal-title":"J Clin Endocrinol Metab"},{"key":"B11","doi-asserted-by":"publisher","DOI":"10.1210\/jc.2011-0385","article-title":"Evaluation, Treatment, and Prevention of Vitamin D Deficiency: An Endocrine Society Clinical Practice Guideline","volume":"96","author":"Holick","year":"2011","journal-title":"J Clin Endocrinol Metab"},{"key":"B12","doi-asserted-by":"publisher","DOI":"10.12861\/jrip.2014.10","article-title":"Efficacy of Supplementary Vitamin D on Improvement of Glycemic Parameters in Patients With Type 2 Diabetes Mellitus; A Randomized Double Blind Clinical Trial","volume":"3","author":"Nasri","year":"2013","journal-title":"J Renal Inj Prev"},{"key":"B13","doi-asserted-by":"publisher","DOI":"10.2337\/dc11-S011","article-title":"American Diabetes Association. 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