{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,8]],"date-time":"2026-07-08T16:47:23Z","timestamp":1783529243178,"version":"3.55.0"},"reference-count":44,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2023,12,28]],"date-time":"2023-12-28T00:00:00Z","timestamp":1703721600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nutrients"],"abstract":"<jats:p>Background: Vitamin D testing (VDT) and supplement use (VDS) are on the rise, but most patients remain deficient (&lt;30 ng\/mL-VDD). We designed the present real-world study to assess this paradox. Methods: We reviewed data from all patients visiting our clinics between 2014 and 2022. We estimated the rate of patients with vitamin D adequacy (\u226530 ng\/mL) (VDA) by year and month of testing, the dose of VDS (low (\u22641200 IU\/day), medium (1201\u20133000 I\/day) and high dose (&gt;3000 IU\/day)), intake duration (short-term (&lt;12 months) and long-term use (\u226512 months)), and timing of use (current use, former use, no use). Results: We enrolled n = 6912 subjects with vitamin D measurements: n = 5195 females (75.2%), age 44.0 \u00b1 16.8 years, BMI 27.9 \u00b1 6.5 kg\/m2; never users: n = 5553 (80.3%), former users: n = 533 (7.7%), current users: n = 826 (12.0%). Current use of VDS was higher in females. VDT rose from 42.1% in 2014 to 92.7% in 2022, and VDA rose from 14.8% to 25.5% for the same time. VDA was found overall in n = 1511 (21.9%); Never users: n = 864 (15.6%), Former users: n = 123 (23.2%); and Current users: n = 370 (44.8%). The maximal VDA (67.9%) was found in subjects using high-dose VDS in the long term. Conclusions: Despite the significant rise in VDT and VDS use, VDA was found in a minority of patients. Prolonged use of high-dose supplements produces modest improvements in VDA.<\/jats:p>","DOI":"10.3390\/nu16010111","type":"journal-article","created":{"date-parts":[[2023,12,28]],"date-time":"2023-12-28T09:35:21Z","timestamp":1703756121000},"page":"111","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Intense Testing and Use of Vitamin D Supplements Leads to Slow Improvement in Vitamin D Adequacy Rates: A Cross-Sectional Analysis of Real-World Data"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2804-0859","authenticated-orcid":false,"given":"Rodis D.","family":"Paparodis","sequence":"first","affiliation":[{"name":"Endocrinology, Diabetes and Metabolism Clinics, Private Practice, 26221 Patras, Greece"},{"name":"Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Toledo, OH 43614, USA"},{"name":"Hellenic Endocrine Network, 10682 Athens, Greece"},{"name":"Department of Medicine, Edward Hines, Jr. VA Hospital, Loyola University Chicago, Hines, IL 60141, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dimitra","family":"Bantouna","sequence":"additional","affiliation":[{"name":"Hellenic Endocrine Network, 10682 Athens, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Evangelos","family":"Karvounis","sequence":"additional","affiliation":[{"name":"Endocrine Surgery Center of Excellence, Euroclinic Hospital, 11528 Athens, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4077-7407","authenticated-orcid":false,"given":"Ioannis","family":"Zoupas","sequence":"additional","affiliation":[{"name":"School of Medicine, University of Athens, 11527 Athens, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sarantis","family":"Livadas","sequence":"additional","affiliation":[{"name":"Hellenic Endocrine Network, 10682 Athens, Greece"},{"name":"Division of Endocrinology, Diabetes and Metabolism, Athens Medical Center, 11528 Athens, Greece"},{"name":"Endocrinology, Diabetes and Metabolism Clinics, Private Practice, 11528 Athens, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8901-7161","authenticated-orcid":false,"given":"Nicholas","family":"Angelopoulos","sequence":"additional","affiliation":[{"name":"Hellenic Endocrine Network, 10682 Athens, Greece"},{"name":"Endocrinology, Diabetes and Metabolism Clinics, Private Practice, 65302 Kavala, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4700-5370","authenticated-orcid":false,"given":"Shahnawaz","family":"Imam","sequence":"additional","affiliation":[{"name":"Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Toledo, OH 43614, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6083-3560","authenticated-orcid":false,"given":"Dimitrios T.","family":"Papadimitriou","sequence":"additional","affiliation":[{"name":"Hellenic Endocrine Network, 10682 Athens, Greece"},{"name":"Medical School, University of Thessaly, 41223 Larisa, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Juan C.","family":"Jaume","sequence":"additional","affiliation":[{"name":"Department of Medicine, Edward Hines, Jr. VA Hospital, Loyola University Chicago, Hines, IL 60141, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,12,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Holick, M.F. 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