{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,10]],"date-time":"2026-01-10T19:26:36Z","timestamp":1768073196890,"version":"3.49.0"},"reference-count":44,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2021,1,20]],"date-time":"2021-01-20T00:00:00Z","timestamp":1611100800000},"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>In chronic kidney disease (CKD) patients, it would be desirable to reduce the intake of inorganic phosphate (P) rather than limit the intake of P contained in proteins. Urinary excretion of P should reflect intestinal absorption of P(inorganic plus protein-derived). The aim of the present study is to determine whether the ratio of urinary P to urinary urea nitrogen (P\/UUN ratio) helps identify patients with a high intake of inorganic P.A cross-sectional study was performed in 71 patients affected by metabolic syndrome with CKD (stages 2\u20133) with normal serum P concentration. A 3-day dietary survey was performed to estimate the average daily amount and the source of P ingested. The daily intake of P was 1086.5 \u00b1 361.3 mg\/day; 64% contained in animal proteins, 22% in vegetable proteins, and 14% as inorganic P. The total amount of P ingested did not correlate with daily phosphaturia, but it did correlate with the P\/UUN ratio (p &lt; 0.018). Patients with the highest tertile of the P\/UUN ratio &gt;71.1 mg\/g presented more abundant inorganic P intake (p &lt; 0.038).The P\/UUN ratio is suggested to be a marker of inorganic P intake. This finding might be useful in clinical practices to identify the source of dietary P and to make personalized dietary recommendations directed to reduce inorganic P intake.<\/jats:p>","DOI":"10.3390\/nu13020292","type":"journal-article","created":{"date-parts":[[2021,1,20]],"date-time":"2021-01-20T12:16:18Z","timestamp":1611144978000},"page":"292","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":15,"title":["Assessment of Inorganic Phosphate Intake by the Measurement of the Phosphate\/Urea Nitrogen Ratio in Urine"],"prefix":"10.3390","volume":"13","author":[{"given":"Mar\u00eda Victoria","family":"Pend\u00f3n-Ruiz de Mier","sequence":"first","affiliation":[{"name":"Maimonides Institute for Biomedical Research of Cordoba (IMIBIC), Reina Sofia University Hospital, Nephrology Service, University of Cordoba, 14004 Cordoba, Spain"},{"name":"Spanish Renal Research Network (REDinREN), Institute of Health Carlos III, 28029 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Noem\u00ed","family":"Vergara","sequence":"additional","affiliation":[{"name":"Maimonides Institute for Biomedical Research of Cordoba (IMIBIC), Reina Sofia University Hospital, Nephrology Service, University of Cordoba, 14004 Cordoba, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8139-3840","authenticated-orcid":false,"given":"Cristian","family":"Rodelo-Haad","sequence":"additional","affiliation":[{"name":"Maimonides Institute for Biomedical Research of Cordoba (IMIBIC), Reina Sofia University Hospital, Nephrology Service, University of Cordoba, 14004 Cordoba, Spain"},{"name":"Spanish Renal Research Network (REDinREN), Institute of Health Carlos III, 28029 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mar\u00eda Dolores","family":"L\u00f3pez-Zamorano","sequence":"additional","affiliation":[{"name":"Nephrology Service, Reina Sofia University Hospital, 14004 Cordoba, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Cristina","family":"Membrives-Gonz\u00e1lez","sequence":"additional","affiliation":[{"name":"Maimonides Institute for Biomedical Research of Cordoba (IMIBIC), Reina Sofia University Hospital, Nephrology Service, University of Cordoba, 14004 Cordoba, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rodrigo","family":"L\u00f3pez-Baltan\u00e1s","sequence":"additional","affiliation":[{"name":"Maimonides Institute for Biomedical Research of Cordoba (IMIBIC), Reina Sofia University Hospital, Nephrology Service, University of Cordoba, 14004 Cordoba, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9341-0724","authenticated-orcid":false,"given":"Juan Rafael","family":"Mu\u00f1oz-Casta\u00f1eda","sequence":"additional","affiliation":[{"name":"Maimonides Institute for Biomedical Research of Cordoba (IMIBIC), Reina Sofia University Hospital, Nephrology Service, University of Cordoba, 14004 Cordoba, Spain"},{"name":"EUTOXandCKD-MBD groups of the ERA-EDTA, Spanish Renal Research Network (REDinREN), Institute of Health Carlos III, 28029 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Francisco","family":"Caravaca","sequence":"additional","affiliation":[{"name":"Nephrology Service, Infanta Cristina Hospital, 06080 Badajoz, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8010-7187","authenticated-orcid":false,"given":"Alejandro","family":"Mart\u00edn-Malo","sequence":"additional","affiliation":[{"name":"Maimonides Institute for Biomedical Research of Cordoba (IMIBIC), Reina Sofia University Hospital, Nephrology Service, University of Cordoba, 14004 Cordoba, Spain"},{"name":"Spanish Renal Research Network (REDinREN), Institute of Health Carlos III, 28029 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Arnold J.","family":"Felsenfeld","sequence":"additional","affiliation":[{"name":"Department of Medicine, Veterans Affairs Greater Los Angeles Healthcare System and the David Geffen School of Medicine, University of California, Los Angeles, CA 90073, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Eugenio J.","family":"De la Torre","sequence":"additional","affiliation":[{"name":"General Medicine, Miguelturra Clinic, 13170 Miguelturra\/Ciudad Real, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sagrario","family":"Soriano","sequence":"additional","affiliation":[{"name":"Maimonides Institute for Biomedical Research of Cordoba (IMIBIC), Reina Sofia University Hospital, Nephrology Service, University of Cordoba, 14004 Cordoba, Spain"},{"name":"Spanish Renal Research Network (REDinREN), Institute of Health Carlos III, 28029 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2627-1445","authenticated-orcid":false,"given":"Rafael","family":"Santamar\u00eda","sequence":"additional","affiliation":[{"name":"Maimonides Institute for Biomedical Research of Cordoba (IMIBIC), Reina Sofia University Hospital, Nephrology Service, University of Cordoba, 14004 Cordoba, Spain"},{"name":"Spanish Renal Research Network (REDinREN), Institute of Health Carlos III, 28029 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mariano","family":"Rodr\u00edguez","sequence":"additional","affiliation":[{"name":"Maimonides Institute for Biomedical Research of Cordoba (IMIBIC), Reina Sofia University Hospital, Nephrology Service, University of Cordoba, 14004 Cordoba, Spain"},{"name":"EUTOXandCKD-MBD groups of the ERA-EDTA, Spanish Renal Research Network (REDinREN), Institute of Health Carlos III, 28029 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,1,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"947","DOI":"10.1038\/ki.2010.281","article-title":"FGF23 or PTH: Which comes first in CKD?","volume":"78","author":"Isakova","year":"2010","journal-title":"Kidney Int."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1407","DOI":"10.1681\/ASN.2012030223","article-title":"Effects of Phosphate Binders in Moderate CKD","volume":"23","author":"Block","year":"2012","journal-title":"JASN"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"519","DOI":"10.2215\/CJN.06080809","article-title":"Understanding sources of dietary phosphorus in the treatment of patients with chronic kidney disease","volume":"5","author":"Gutekunst","year":"2010","journal-title":"Clin. 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