{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,17]],"date-time":"2026-10-17T06:41:54Z","timestamp":1792219314276,"version":"4.4.0"},"reference-count":23,"publisher":"Wiley","license":[{"start":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T00:00:00Z","timestamp":1792108800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"},{"start":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T00:00:00Z","timestamp":1792108800000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"content-domain":{"domain":["bjui-journals.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["BJU International"],"abstract":"\n Objectives<\/jats:title>\n To explore the relationship between diet, mission phase, urinary calcium, and urinary oxalate during long\u2010duration spaceflight.<\/jats:p>\n <\/jats:sec>\n \n Subjects and Methods<\/jats:title>\n Dietary intake of calcium and oxalate and 24\u2010h urine parameters from 12 astronauts during long\u2010duration spaceflight while consuming controlled diets were analysed. Mixed\u2010effects models assessed differences in urinary calcium and oxalate levels, adjusting for daily intake of calcium and oxalate, and for in\u2010flight status relative to pre\u2010flight status.<\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n \n From pre\u2010flight to in\u2010flight, median urinary calcium increased from 178.9 to 270.3\u2009mg\/day (\n P<\/jats:italic>\n \u2009<\u20090.01) and urinary oxalate from 37.9 to 42.3\u2009mg\/day (\n P<\/jats:italic>\n \u2009<\u20090.05). Post\u2010flight, urinary calcium decreased to 185.8\u2009mg\/day (\n P<\/jats:italic>\n \u2009<\u20090.01) and urinary oxalate to 31.5\u2009mg\/day (\n P<\/jats:italic>\n \u2009<\u20090.01), relative to in\u2010flight values. Dietary oxalate remained similar pre\u2010flight and in\u2010flight (382.0 vs 339.4\u2009mg\/day;\n P<\/jats:italic>\n \u2009\u2265\u20090.05) but decreased post\u2010flight to 241.6\u2009mg\/day (\n P<\/jats:italic>\n \u2009<\u20090.01). Adjusted in\u2010flight urinary oxalate was 10.71\u2009mg\/day higher than pre\u2010flight and increased by 0.050\u2009mg\/day per 1\u2010mg\/day increase in dietary oxalate (95% confidence interval 0.036\u20130.064;\n P<\/jats:italic>\n \u2009<\u20090.001); dietary calcium was not associated with urinary oxalate (\n P<\/jats:italic>\n \u2009\u2265\u20090.05).\n <\/jats:p>\n <\/jats:sec>\n \n Conclusions<\/jats:title>\n Hyperoxaluria was observed during long\u2010duration spaceflights and persisted throughout the in\u2010flight phase under controlled dietary conditions. Although high dietary oxalate was the strongest predictor, evidence of inter\u2010individual susceptibility was observed, with some astronauts exhibiting elevated oxalate pre\u2010flight levels, which increased further during flight. Assessment of oxalate content in current astronaut food systems, mitigation of dietary oxalate load through timed calcium intake, and further investigation of microgravity\u2010related effects on oxalate absorption and metabolism are required.<\/jats:p>\n <\/jats:sec>","DOI":"10.1111\/bju.70484","type":"journal-article","created":{"date-parts":[[2026,10,17]],"date-time":"2026-10-17T06:05:57Z","timestamp":1792217157000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Urinary oxalate excretion in astronauts during long\u2010duration spaceflight: an exploratory analysis"],"prefix":"10.1111","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0700-5686","authenticated-orcid":false,"given":"Juliana","family":"Villanueva\u2010Congote","sequence":"first","affiliation":[{"name":"Department of Urology Massachusetts General Hospital Boston MA USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-8390-8026","authenticated-orcid":false,"given":"Stephanie","family":"Smith","sequence":"additional","affiliation":[{"name":"University of Minnesota Medical School Minneapolis MN USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3368-9938","authenticated-orcid":false,"given":"Nathaniel","family":"Hansen","sequence":"additional","affiliation":[{"name":"Department of Urology Brigham and Women's Hospital Boston MA USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5946-4991","authenticated-orcid":false,"given":"Raeann","family":"Dalton","sequence":"additional","affiliation":[{"name":"Division of Urologic Surgery Maine Medical Center Portland ME USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Evelyn","family":"James","sequence":"additional","affiliation":[{"name":"Tufts University School of Medicine Boston MA USA"},{"name":"Division of Urologic Surgery Maine Medical Center Portland ME USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4591-4431","authenticated-orcid":false,"given":"Jay","family":"Buckey","sequence":"additional","affiliation":[{"name":"Geisel School of Medicine at Dartmouth Hanover NH USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2913-0418","authenticated-orcid":false,"given":"Daniel A.","family":"Wollin","sequence":"additional","affiliation":[{"name":"Department of Urology Brigham and Women's Hospital Boston MA USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0448-4765","authenticated-orcid":false,"given":"David W.","family":"Sobel","sequence":"additional","affiliation":[{"name":"Tufts University School of Medicine Boston MA USA"},{"name":"Division of Urologic Surgery Maine Medical 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