{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,31]],"date-time":"2025-10-31T21:58:52Z","timestamp":1761947932794,"version":"3.40.4"},"reference-count":15,"publisher":"S. Karger AG","issue":"2","license":[{"start":{"date-parts":[[2013,12,18]],"date-time":"2013-12-18T00:00:00Z","timestamp":1387324800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/www.karger.com\/Services\/SiteLicenses"},{"start":{"date-parts":[[2013,12,18]],"date-time":"2013-12-18T00:00:00Z","timestamp":1387324800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/www.karger.com\/Services\/SiteLicenses"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Neonatology"],"published-print":{"date-parts":[[2014]]},"abstract":"<b><i>Background: <\/i><\/b>The relative dose response (RDR) test, which quantifies the increase in serum retinol after vitamin A administration, is a qualitative measure of liver vitamin A stores. Particularly in preterm infants, the feasibility of the RDR test involving blood is critically dependent on small sample volumes. <b><i>Objectives:<\/i><\/b> This study aimed to assess whether the RDR calculated with retinol-binding protein 4 (RBP4) might be a substitute for the classical retinol-based RDR test for assessing vitamin A status in very preterm infants. <b><i>Methods:<\/i><\/b> This study included preterm infants with a birth weight below 1,500 g (n = 63, median birth weight 985 g, median gestational age 27.4 weeks) who were treated with 5,000 IU retinyl palmitate intramuscularly 3 times a week for 4 weeks. On day 3 (first vitamin A injection) and day 28 of life (last vitamin A injection), the RDR was calculated and compared using serum retinol and RBP4 concentrations. <b><i>Results:<\/i><\/b> The concentrations of retinol (p < 0.001) and RBP4 (p < 0.01) increased significantly from day 3 to day 28. On day 3, the median (IQR) retinol-RDR was 27% (8.4-42.5) and the median RBP4-RDR was 8.4% (-3.4 to 27.9), compared to 7.5% (-10.6 to 20.8) and -0.61% (-19.7 to 15.3) on day 28. The results for retinol-RDR and RBP4-RDR revealed no significant correlation. The agreement between retinol-RDR and RBP4-RDR was poor (day 3: Cohen's &#954; = 0.12; day 28: Cohen's &#954; = 0.18). <b><i>Conclusion:<\/i><\/b> The RDR test based on circulating RBP4 is unlikely to reflect the hepatic vitamin A status in preterm infants.<\/jats:p>","DOI":"10.1159\/000356773","type":"journal-article","created":{"date-parts":[[2013,12,18]],"date-time":"2013-12-18T08:34:49Z","timestamp":1387355689000},"page":"155-160","source":"Crossref","is-referenced-by-count":5,"title":["The Relative Dose Response Test Based on Retinol-Binding Protein 4 Is Not Suitable to Assess Vitamin A Status in Very Low Birth Weight Infants"],"prefix":"10.1159","volume":"105","author":[{"given":"Bettina","family":"Schmiedchen","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ann Carolin","family":"Longardt","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Christoph","family":"B\u00fchrer","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jens","family":"Raila","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Andrea","family":"Loui","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Florian J.","family":"Schweigert","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"127","published-online":{"date-parts":[[2013,12,18]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","DOI":"10.1136%2Fadc.2004.057547"},{"key":"ref2","doi-asserted-by":"publisher","DOI":"10.1007%2Fs00394-007-1001-z"},{"key":"ref3","doi-asserted-by":"publisher","DOI":"10.1017%2FS0007114509993072"},{"key":"ref4","doi-asserted-by":"publisher","DOI":"10.1097%2F00005176-198601000-00020"},{"key":"ref5","doi-asserted-by":"publisher","DOI":"10.1016%2F0378-3782%2892%2990143-5"},{"key":"ref6","doi-asserted-by":"publisher","DOI":"10.1067%2Fmpd.2003.214"},{"key":"ref7","doi-asserted-by":"publisher","DOI":"10.1056%2FNEJM199906243402505"},{"key":"ref8","doi-asserted-by":"publisher","DOI":"10.1006%2Fbmme.1995.1010"},{"key":"ref9","doi-asserted-by":"publisher","DOI":"10.1186%2F1475-2891-2-17"},{"key":"ref10","doi-asserted-by":"publisher","DOI":"10.1038%2Fsj.ki.5002372"},{"key":"ref11","doi-asserted-by":"publisher","DOI":"10.1093%2Fhumrep%2Fdeg249"},{"key":"ref12","doi-asserted-by":"publisher","DOI":"10.3945%2Fajcn.2009.27569"},{"key":"ref13","doi-asserted-by":"publisher","DOI":"10.1016%2FS0022-3476%2805%2981614-2"},{"key":"ref14","doi-asserted-by":"publisher","DOI":"10.1111%2Fj.1365-277X.2010.01072.x"},{"key":"ref15","doi-asserted-by":"publisher","DOI":"10.3748%2Fwjg.14.6133"}],"container-title":["Neonatology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/356773","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/356773","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,4,23]],"date-time":"2025-04-23T18:21:44Z","timestamp":1745432504000},"score":1,"resource":{"primary":{"URL":"https:\/\/karger.com\/article\/doi\/10.1159\/000356773"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2013,12,18]]},"references-count":15,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2014,2,1]]},"published-print":{"date-parts":[[2014,2,6]]}},"URL":"https:\/\/doi.org\/10.1159\/000356773","archive":["Portico"],"relation":{},"ISSN":["1661-7800","1661-7819"],"issn-type":[{"type":"print","value":"1661-7800"},{"type":"electronic","value":"1661-7819"}],"subject":[],"published":{"date-parts":[[2013,12,18]]}}}