{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,18]],"date-time":"2026-06-18T20:17:30Z","timestamp":1781813850954,"version":"3.54.5"},"reference-count":29,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2013,9,5]],"date-time":"2013-09-05T00:00:00Z","timestamp":1378339200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nutrients"],"abstract":"<jats:p>Use of hormonal contraceptives (HC) may influence total plasma concentrations of vitamin D metabolites. A likely cause is an increased synthesis of vitamin D binding protein (VDBP). Discrepant results are reported on whether the use of HC affects free concentrations of vitamin D metabolites. Aim: In a cross-sectional study, plasma concentrations of vitamin D metabolites, VDBP, and the calculated free vitamin D index in users and non-users of HC were compared and markers of calcium and bone metabolism investigated. Results: 75 Caucasian women aged 25\u201335 years were included during  winter season. Compared with non-users (n = 23), users of HC (n = 52) had significantly higher plasma concentrations of 25-hydroxyvitamin D (25OHD) (median 84 interquartile range: [67\u2013111] vs. 70 [47\u201383] nmol\/L, p = 0.01), 1,25-dihydroxyvitamin D (1,25(OH)2D) (198 [163\u2013241] vs. 158 [123\u2013183] pmol\/L, p = 0.01) and VDBP (358 [260\u2013432] vs. 271 [179\u2013302] \u00b5g\/mL, p &lt; 0.001). However, the calculated free indices (FI-25OHD and FI-1,25(OH)2D) were not significantly different between groups (p &gt; 0.10). There were no significant differences in indices of calcium homeostasis (plasma concentrations of calcium, parathyroid hormone, and calcitonin, p &gt; 0.21) or bone metabolism (plasma bone specific alkaline phosphatase, osteocalcin, and urinary NTX\/creatinine ratio) between groups. In conclusion: Use of HC is associated with 13%\u201325% higher concentrations of total vitamin D metabolites and VDBP. This however is not reflected in indices of calcium or bone metabolism. Use of HC should be considered in the interpretation of plasma concentrations vitamin D metabolites.<\/jats:p>","DOI":"10.3390\/nu5093470","type":"journal-article","created":{"date-parts":[[2013,9,5]],"date-time":"2013-09-05T10:54:54Z","timestamp":1378378494000},"page":"3470-3480","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":66,"title":["Increased Plasma Concentrations of Vitamin D Metabolites and Vitamin D Binding Protein in Women Using Hormonal Contraceptives: A Cross-Sectional Study"],"prefix":"10.3390","volume":"5","author":[{"given":"Ulla","family":"M\u00f8ller","sequence":"first","affiliation":[{"name":"Department of Endocrinology and Internal Medicine, THG, Aarhus University Hospital,  Tage Hansens Gade 2, DK, Aarhus 8000, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Susanna","family":"Streym","sequence":"additional","affiliation":[{"name":"Department of Endocrinology and Internal Medicine, THG, Aarhus University Hospital,  Tage Hansens Gade 2, DK, Aarhus 8000, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lars","family":"Jensen","sequence":"additional","affiliation":[{"name":"Department of Clinical Physiology, Glostrup University Hospital, Copenhagen DK-2900, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Leif","family":"Mosekilde","sequence":"additional","affiliation":[{"name":"Department of Endocrinology and Internal Medicine, THG, Aarhus University Hospital,  Tage Hansens Gade 2, DK, Aarhus 8000, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Inez","family":"Schoenmakers","sequence":"additional","affiliation":[{"name":"MRC Human Nutrition Research, Cambridge CB1 9NL, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shailja","family":"Nigdikar","sequence":"additional","affiliation":[{"name":"MRC Human Nutrition Research, Cambridge CB1 9NL, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lars","family":"Rejnmark","sequence":"additional","affiliation":[{"name":"Department of Endocrinology and Internal Medicine, THG, Aarhus University Hospital,  Tage Hansens Gade 2, DK, Aarhus 8000, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2013,9,5]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"73","DOI":"10.1016\/j.annepidem.2007.12.001","article-title":"Vitamin D status: Measurement, interpretation, and clinical application","volume":"19","author":"Holick","year":"2009","journal-title":"Ann. 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