{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,23]],"date-time":"2026-09-23T04:44:50Z","timestamp":1790138690430,"version":"4.0.1"},"reference-count":12,"publisher":"Bioscientifica","issue":"1","license":[{"start":{"date-parts":[[2026,1,1]],"date-time":"2026-01-01T00:00:00Z","timestamp":1767225600000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"content-domain":{"domain":["raf.bioscientifica.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2026,2,18]]},"abstract":"\n Graphical Abstract<\/jats:title>\n \n \n <\/jats:p>\n <\/jats:sec>\n \n Lay summary<\/jats:title>\n \n In the studies assessing the relationship between vitamin D levels and pregnancy outcomes in\n in vitro<\/jats:italic>\n fertilization, doctors sometimes collected and froze the follicular fluid (fluid around eggs in a woman\u2019s ovaries) so they can test it later for research. This study aimed to find out if freezing and storage changes the level of vitamin D in that fluid, which could affect how reliable the tests are. We collected follicular fluid of 20 women going through\n in vitro<\/jats:italic>\n fertilization. The samples were split into portions and were frozen at two different temperatures: \u221220 and \u221280\u00b0C. Vitamin D levels were analysed at baseline (before freezing), after 2 weeks and again after 7 months. The results showed that freezing and storage did not make a noticeable difference in vitamin D levels. That means storing the fluid this way for up to 7 months is an acceptable method for research.\n <\/jats:p>\n <\/jats:sec>","DOI":"10.1530\/raf-25-0170","type":"journal-article","created":{"date-parts":[[2026,2,18]],"date-time":"2026-02-18T14:12:27Z","timestamp":1771423947000},"update-policy":"https:\/\/doi.org\/10.1530\/crossmarkpolicy-13","source":"Crossref","is-referenced-by-count":1,"title":["Effect of freezing and cryostorage on follicular fluid vitamin D levels"],"prefix":"10.1530","volume":"7","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0475-0645","authenticated-orcid":true,"given":"Jennifer K Y","family":"Ko","sequence":"first","affiliation":[{"name":"Department of Obstetrics and Gynaecology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9385-4846","authenticated-orcid":true,"given":"Kevin K W","family":"Lam","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynaecology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tat On","family":"Chan","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynaecology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Raymond H W","family":"Li","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynaecology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ernest H Y","family":"Ng","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynaecology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"416","reference":[{"key":"bib1","article-title":"A proposal for strength-of-agreement criteria for Lin\u2019s concordance correlation","author":"McBride GB","year":"2005","unstructured":"McBride GB\n\n 2005 A proposal for strength-of-agreement criteria for Lin\u2019s concordance correlation. National Institute of Water & Atmospheric Reseach Ltd., New Zealand (https:\/\/www.medcalc.org\/download\/pdf\/McBride2005.pdf). Accessed on 2 May 2024."},{"key":"bib2","series-title":"Eur J Clin Nutr","first-page":"231","article-title":"Vitamin D testing: advantages and limits of the current assays","volume":"74","author":"Altieri B","year":"2020","unstructured":"Altieri B\n, \nCavalier E\n, \nBhattoa HP\n, et al.\n 2020 Vitamin D testing: advantages and limits of the current assays. Eur J Clin Nutr 74 231\u2013247. (https:\/\/doi.org\/10.1038\/s41430-019-0553-3)"},{"key":"bib3","series-title":"Endocr Connect","article-title":"100 years of vitamin D: effect of serum vitamin D level before ovarian stimulation on the cumulative live birth rate of women undergoing in vitro fertilization: a retrospective analysis","volume":"11","author":"Ko JKY","year":"2022","unstructured":"Ko JKY\n, \nShi J\n, \nLi RHW\n, et al.\n 2022 100 years of vitamin D: effect of serum vitamin D level before ovarian stimulation on the cumulative live birth rate of women undergoing in vitro fertilization: a retrospective analysis. Endocr Connect 11 e210444. (https:\/\/doi.org\/10.1530\/ec-21-0444)"},{"key":"bib4","series-title":"Sci Rep","article-title":"Effect of freezing and storage on serum vitamin D levels measured by mass spectrometry and immunoassay in reproductive age women","volume":"15","author":"Ko JKY","year":"2025","unstructured":"Ko JKY\n, \nChen SPL\n, \nLam KKW\n, et al.\n 2025 Effect of freezing and storage on serum vitamin D levels measured by mass spectrometry and immunoassay in reproductive age women. Sci Rep 15 21314. (https:\/\/doi.org\/10.1038\/s41598-025-02811-4)"},{"key":"bib5","series-title":"Nutrients","first-page":"3783","article-title":"Reducing storage-related bias in reproductive vitamin D research: towards a stable and reliable biomarker of ovarian vitamin D status","volume":"17","author":"Lara-Molina EE","year":"2025","unstructured":"Lara-Molina EE\n, \nFranasiak JM\n, \nDevesa-Peiro A\n, et al.\n 2025 Reducing storage-related bias in reproductive vitamin D research: towards a stable and reliable biomarker of ovarian vitamin D status. Nutrients 17 3783. (https:\/\/doi.org\/10.3390\/nu17233783)"},{"key":"bib6","series-title":"Gynecol Endocrinol","first-page":"28","article-title":"Vitamin D and anti-Mullerian hormone concentration in human follicular fluid individually aspirated from all patient follicles","volume":"38","author":"Skowronska P","year":"2022","unstructured":"Skowronska P\n, \nKunicki M\n, \nPastuszek E\n, et al.\n 2022 Vitamin D and anti-Mullerian hormone concentration in human follicular fluid individually aspirated from all patient follicles. Gynecol Endocrinol 38 28\u201332. (https:\/\/doi.org\/10.1080\/09513590.2021.1933934)"},{"key":"bib1","article-title":"A proposal for strength-of-agreement criteria for Lin\u2019s concordance correlation","author":"McBride GB","year":"2005","unstructured":"McBride GB\n\n 2005 A proposal for strength-of-agreement criteria for Lin\u2019s concordance correlation. National Institute of Water & Atmospheric Reseach Ltd., New Zealand (https:\/\/www.medcalc.org\/download\/pdf\/McBride2005.pdf). Accessed on 2 May 2024."},{"key":"bib2","series-title":"Eur J Clin Nutr","first-page":"231","article-title":"Vitamin D testing: advantages and limits of the current assays","volume":"74","author":"Altieri B","year":"2020","unstructured":"Altieri B\n, \nCavalier E\n, \nBhattoa HP\n, et al.\n 2020 Vitamin D testing: advantages and limits of the current assays. Eur J Clin Nutr 74 231\u2013247. (https:\/\/doi.org\/10.1038\/s41430-019-0553-3)"},{"key":"bib3","series-title":"Endocr Connect","article-title":"100 years of vitamin D: effect of serum vitamin D level before ovarian stimulation on the cumulative live birth rate of women undergoing in vitro fertilization: a retrospective analysis","volume":"11","author":"Ko JKY","year":"2022","unstructured":"Ko JKY\n, \nShi J\n, \nLi RHW\n, et al.\n 2022 100 years of vitamin D: effect of serum vitamin D level before ovarian stimulation on the cumulative live birth rate of women undergoing in vitro fertilization: a retrospective analysis. Endocr Connect 11 e210444. (https:\/\/doi.org\/10.1530\/ec-21-0444)"},{"key":"bib4","series-title":"Sci Rep","article-title":"Effect of freezing and storage on serum vitamin D levels measured by mass spectrometry and immunoassay in reproductive age women","volume":"15","author":"Ko JKY","year":"2025","unstructured":"Ko JKY\n, \nChen SPL\n, \nLam KKW\n, et al.\n 2025 Effect of freezing and storage on serum vitamin D levels measured by mass spectrometry and immunoassay in reproductive age women. Sci Rep 15 21314. (https:\/\/doi.org\/10.1038\/s41598-025-02811-4)"},{"key":"bib5","series-title":"Nutrients","first-page":"3783","article-title":"Reducing storage-related bias in reproductive vitamin D research: towards a stable and reliable biomarker of ovarian vitamin D status","volume":"17","author":"Lara-Molina EE","year":"2025","unstructured":"Lara-Molina EE\n, \nFranasiak JM\n, \nDevesa-Peiro A\n, et al.\n 2025 Reducing storage-related bias in reproductive vitamin D research: towards a stable and reliable biomarker of ovarian vitamin D status. Nutrients 17 3783. (https:\/\/doi.org\/10.3390\/nu17233783)"},{"key":"bib6","series-title":"Gynecol Endocrinol","first-page":"28","article-title":"Vitamin D and anti-Mullerian hormone concentration in human follicular fluid individually aspirated from all patient follicles","volume":"38","author":"Skowronska P","year":"2022","unstructured":"Skowronska P\n, \nKunicki M\n, \nPastuszek E\n, et al.\n 2022 Vitamin D and anti-Mullerian hormone concentration in human follicular fluid individually aspirated from all patient follicles. Gynecol Endocrinol 38 28\u201332. (https:\/\/doi.org\/10.1080\/09513590.2021.1933934)"}],"container-title":["Reproduction and Fertility"],"original-title":[],"link":[{"URL":"https:\/\/raf.bioscientifica.com\/view\/journals\/raf\/7\/1\/RAF-25-0170.xml","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/raf.bioscientifica.com\/downloadpdf\/journals\/raf\/7\/1\/RAF-25-0170.xml","content-type":"text\/html","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/raf.bioscientifica.com\/downloadpdf\/journals\/raf\/7\/1\/RAF-25-0170.xml","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,26]],"date-time":"2026-03-26T18:11:38Z","timestamp":1774548698000},"score":1,"resource":{"primary":{"URL":"https:\/\/raf.bioscientifica.com\/view\/journals\/raf\/7\/1\/RAF-25-0170.xml"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,1,1]]},"references-count":12,"journal-issue":{"issue":"1"},"URL":"https:\/\/doi.org\/10.1530\/raf-25-0170","relation":{},"ISSN":["2633-8386"],"issn-type":[{"value":"2633-8386","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,1,1]]}}}