{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,1]],"date-time":"2026-01-01T09:50:06Z","timestamp":1767261006032,"version":"build-2065373602"},"reference-count":38,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2025,10,22]],"date-time":"2025-10-22T00:00:00Z","timestamp":1761091200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Spanish government"},{"DOI":"10.13039\/501100004587","name":"Instituto de Salud Carlos III","doi-asserted-by":"crossref","award":["PI23\/01428"],"award-info":[{"award-number":["PI23\/01428"]}],"id":[{"id":"10.13039\/501100004587","id-type":"DOI","asserted-by":"crossref"}]},{"name":"European Funds","award":["PI21\/0654"],"award-info":[{"award-number":["PI21\/0654"]}]},{"name":"the Junta de Andaluc\u00eda and EUTOX","award":["PI-0183-2024"],"award-info":[{"award-number":["PI-0183-2024"]}]},{"name":"EUTOX","award":["RD24\/0004\/0004"],"award-info":[{"award-number":["RD24\/0004\/0004"]}]},{"name":"Cost action PerMedik","award":["CA21165"],"award-info":[{"award-number":["CA21165"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nutrients"],"abstract":"<jats:p>Background\/Objectives: It would be desirable to reduce the intake of inorganic phosphate (P), which is easily absorbed and is associated with cardiovascular disease. The phosphate-to-urea nitrogen ratio (P\/UUN) in urine should reflect the proportion of inorganic P ingested relative to protein intake. In this manuscript, we will refer to this parameter as P\/UUN, which is conceptually equivalent to the phosphate-to-urea ratio (P\/U). These studies aim to evaluate whether an increased intake of inorganic P translates into an increase in the P\/UUN. Methods: A total of 18 healthy volunteers (Study-1) and 18 chronic kidney disease patients (Study-2) were included. At baseline, all participants completed a 3-day dietary survey, and on the third day collected a 24 h urine sample. In Study-2, blood samples were also obtained. Participants were then stratified into three groups (6 per group) for a 3-day dietary intervention: control group: maintained their usual diet; soda group: consumed soda zero, a source of added inorganic P; and processed cheese group: consumed fresh processed cheese, which includes both organic and inorganic P additives. At last visit, all participants again completed a 3-day dietary survey and collected a 24 h urine sample (and blood samples in Study-2). Dietary P intake was estimated using two tools: the diet calibrator and the Spanish Food Composition Database (BEDCA). Results: After the intervention, neither BEDCA nor the diet calibrator was able to provide an accurate measurement of inorganic P ingested. However, only in the soda group, P\/UUN increased in both studies (p = 0.046 and 0.047). In Study-2, the levels of FGF23 and klotho remained unchanged (p = 0.9 and p = 0.7, respectively). Conclusions: These findings suggest that urinary P\/UUN ratio may be a useful biomarker to monitor changes in inorganic P intake and could help to individualize dietary recommendations to reduce inorganic P exposure without restricting protein intake.<\/jats:p>","DOI":"10.3390\/nu17213323","type":"journal-article","created":{"date-parts":[[2025,10,23]],"date-time":"2025-10-23T02:03:48Z","timestamp":1761185028000},"page":"3323","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["The Phosphate\/Urea Nitrogen Ratio in Urine\u2014A Method to Assess the Relative Intake of Inorganic Phosphate"],"prefix":"10.3390","volume":"17","author":[{"given":"Carlos","family":"Novillo","sequence":"first","affiliation":[{"name":"Unidad de Gesti\u00f3n Cl\u00ednica Nefrolog\u00eda, Reina Sofia University Hospital, 14004 Cordoba, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0001-8502-3564","authenticated-orcid":false,"given":"Raquel M.","family":"Garc\u00eda-Saez","sequence":"additional","affiliation":[{"name":"Instituto Maim\u00f3nides de Investigaci\u00f3n Biom\u00e9dica de C\u00f3rdoba (IMIBIC), Unidad de Gesti\u00f3n Cl\u00ednica Nefrolog\u00eda, Reina Sofia University Hospital, Department of Medicine, University of Cordoba, 14004 Cordoba, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Laura","family":"S\u00e1nchez-Molina","sequence":"additional","affiliation":[{"name":"Department of Medicine, 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":"Instituto Maim\u00f3nides de Investigaci\u00f3n Biom\u00e9dica de C\u00f3rdoba (IMIBIC), Unidad de Gesti\u00f3n Cl\u00ednica Nefrolog\u00eda, Reina Sofia University Hospital, Department of Medicine, University of Cordoba, 14004 Cordoba, Spain"},{"name":"Redes de Investigaci\u00f3n Cooperativa Orientadas a Resultados en Salud (RICORS), Instituto de Salud Carlos III, RD24\/0004\/0004, 28029 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1830-2096","authenticated-orcid":false,"given":"Andr\u00e9s","family":"Carmona","sequence":"additional","affiliation":[{"name":"Instituto Maim\u00f3nides de Investigaci\u00f3n Biom\u00e9dica de C\u00f3rdoba (IMIBIC), Unidad de Gesti\u00f3n Cl\u00ednica Nefrolog\u00eda, Reina Sofia University Hospital, Department of Medicine, University of Cordoba, 14004 Cordoba, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gonzalo","family":"Pinaglia-Tobaruela","sequence":"additional","affiliation":[{"name":"Instituto Maim\u00f3nides de Investigaci\u00f3n Biom\u00e9dica de C\u00f3rdoba (IMIBIC), Unidad de Gesti\u00f3n Cl\u00ednica Nefrolog\u00eda, Reina Sofia University Hospital, Department of Medicine, University of Cordoba, 14004 Cordoba, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Cristina","family":"Membrives-Gonz\u00e1lez","sequence":"additional","affiliation":[{"name":"Instituto Maim\u00f3nides de Investigaci\u00f3n Biom\u00e9dica de C\u00f3rdoba (IMIBIC), Unidad de Gesti\u00f3n Cl\u00ednica Nefrolog\u00eda, Reina Sofia University Hospital, Department of Medicine, University of Cordoba, 14004 Cordoba, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Daniel","family":"Jurado","sequence":"additional","affiliation":[{"name":"Instituto Maim\u00f3nides de Investigaci\u00f3n Biom\u00e9dica de C\u00f3rdoba (IMIBIC), Unidad de Gesti\u00f3n Cl\u00ednica Nefrolog\u00eda, Reina Sofia University Hospital, Department of Medicine, University of Cordoba, 14004 Cordoba, 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":"Instituto Maim\u00f3nides de Investigaci\u00f3n Biom\u00e9dica de C\u00f3rdoba (IMIBIC), Unidad de Gesti\u00f3n Cl\u00ednica Nefrolog\u00eda, Reina Sofia University Hospital, Department of Medicine, University of Cordoba, 14004 Cordoba, Spain"},{"name":"Redes de Investigaci\u00f3n Cooperativa Orientadas a Resultados en Salud (RICORS), Instituto de Salud Carlos III, RD24\/0004\/0004, 28029 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9341-0724","authenticated-orcid":false,"given":"Juan R.","family":"Mu\u00f1oz-Casta\u00f1eda","sequence":"additional","affiliation":[{"name":"Instituto Maim\u00f3nides de Investigaci\u00f3n Biom\u00e9dica de C\u00f3rdoba (IMIBIC), Unidad de Gesti\u00f3n Cl\u00ednica Nefrolog\u00eda, Reina Sofia University Hospital, Department of Medicine, University of Cordoba, 14004 Cordoba, Spain"},{"name":"Redes de Investigaci\u00f3n Cooperativa Orientadas a Resultados en Salud (RICORS), Instituto de Salud Carlos III, RD24\/0004\/0004, 28029 Madrid, 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":"Instituto Maim\u00f3nides de Investigaci\u00f3n Biom\u00e9dica de C\u00f3rdoba (IMIBIC), Unidad de Gesti\u00f3n Cl\u00ednica Nefrolog\u00eda, Reina Sofia University Hospital, Department of Medicine, University of Cordoba, 14004 Cordoba, Spain"},{"name":"Redes de Investigaci\u00f3n Cooperativa Orientadas a Resultados en Salud (RICORS), Instituto de Salud Carlos III, RD24\/0004\/0004, 28029 Madrid, 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Cordoba, 14004 Cordoba, Spain"},{"name":"Redes de Investigaci\u00f3n Cooperativa Orientadas a Resultados en Salud (RICORS), Instituto de Salud Carlos III, RD24\/0004\/0004, 28029 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Victoria","family":"Pend\u00f3n-RuizdeMier","sequence":"additional","affiliation":[{"name":"Instituto Maim\u00f3nides de Investigaci\u00f3n Biom\u00e9dica de C\u00f3rdoba (IMIBIC), Unidad de Gesti\u00f3n Cl\u00ednica Nefrolog\u00eda, Reina Sofia University Hospital, Department of Medicine, University of Cordoba, 14004 Cordoba, Spain"},{"name":"Redes de Investigaci\u00f3n Cooperativa Orientadas a Resultados en Salud (RICORS), Instituto de Salud Carlos III, RD24\/0004\/0004, 28029 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,10,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1016\/j.nefro.2018.09.002","article-title":"The Spanish Society of Nephrology (SENEFRO) commentary to the Spain GBD 2016 report: Keeping chronic kidney disease out of sight of health authorities will only magnify the problem","volume":"39","author":"Ortiz","year":"2019","journal-title":"Nefrologia"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1016\/j.kisu.2021.11.003","article-title":"Epidemiology of chronic kidney disease: An update 2022","volume":"12","author":"Kovesdy","year":"2022","journal-title":"Kidney Int. Suppl."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Santamar\u00eda, R., D\u00edaz-Tocados, J.M., Pend\u00f3n-Ruiz de Mier, M.V., Robles, A., Salmer\u00f3n-Rodr\u00edguez, M.D., Ruiz, E., Vergara, N., Aguilera-Tejero, E., Raya, A., and Ortega, R. (2018). Increased Phosphaturia Accelerates The Decline in Renal Function: A Search for Mechanisms. Sci. Rep., 8.","DOI":"10.1038\/s41598-018-32065-2"},{"key":"ref_4","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":"Isakowa","year":"2010","journal-title":"Kidney Int."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"i46","DOI":"10.1093\/ckj\/sfae434","article-title":"The true cost of phosphate control in chronic kidney disease","volume":"18","year":"2025","journal-title":"Clin. Kidney J."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"2627","DOI":"10.1161\/CIRCULATIONAHA.105.553198","article-title":"Cholesterol And Recurrent Events Trial Investigators Relation between serum phosphate level and cardiovascular event rate in people with coronary disease","volume":"112","author":"Tonelli","year":"2005","journal-title":"Circulation"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"879","DOI":"10.1001\/archinte.167.9.879","article-title":"Relations of Serum Phosphorus and Calcium Levels to the Incidence of Cardiovascular Disease in the Community","volume":"167","author":"Dhingra","year":"2007","journal-title":"Arch. Intern. Med."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"113","DOI":"10.1053\/j.ackd.2010.12.003","article-title":"Phosphate and Cardiovascular Disease","volume":"18","author":"Kendrick","year":"2011","journal-title":"Adv. Chronic Kidney Dis."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1060","DOI":"10.1016\/j.kint.2017.11.036","article-title":"Prevention and treatment of hyperphosphatemia in chronic kidney disease","volume":"93","author":"Vervloet","year":"2018","journal-title":"Kidney Int."},{"key":"ref_10","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":"J. Am. Soc. Nephrol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"416","DOI":"10.1053\/j.jrn.2011.04.004","article-title":"Differences Among Total and In Vitro Digestible Phosphorus Content of Plant Foods and Beverages","volume":"22","author":"Karp","year":"2012","journal-title":"J. Renal Nutr."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"257","DOI":"10.2215\/CJN.05040610","article-title":"Vegetarian Compared with Meat Dietary Protein Source and Phosphorus Homeostasis in Chronic Kidney Disease","volume":"6","author":"Moe","year":"2011","journal-title":"Clin. J. Am. Soc. Nephrol."},{"key":"ref_13","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. J. Am. Soc. Nephrol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1038\/nrneph.2016.164","article-title":"On behalf of the ERA\u2013EDTA Working Group on Chronic Kidney Disease\u2014Mineral and Bone Disorders and the European Renal Nutrition Working Group; The role of phosphate in kidney disease","volume":"13","author":"Vervloet","year":"2017","journal-title":"Nat. Rev. Nephrol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"101","DOI":"10.2337\/ds16-0048","article-title":"Phosphate Additive Avoidance in Chronic Kidney Disease","volume":"30","author":"Goldfarb","year":"2017","journal-title":"Diabetes Spectr."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"6","DOI":"10.3945\/ajcn.112.053934","article-title":"Public health impact of dietary phosphorus excess on bone and cardiovascular health in the general population","volume":"98","author":"Calvo","year":"2013","journal-title":"Am. J. Clin. Nutr."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Pend\u00f3n-Ruiz de Mier, M.V., Vergara, N., Rodelo-Haad, C., L\u00f3pez-Zamorano, M.D., Membrives-Gonz\u00e1lez, C., L\u00f3pez-Baltan\u00e1s, R., Mu\u00f1oz-Casta\u00f1eda, J.R., Caravaca, F., Mart\u00edn-Malo, A., and Felsenfeld, A.J. (2021). Assessment of inorganic phosphate intake by the measurement of the phosphate\/urea nitrogen ratio in urine. Nutrients, 13.","DOI":"10.3390\/nu13020292"},{"key":"ref_18","unstructured":"(2020, July 12). Spanish Food Composition Database Published by the BEDCA Network of the Ministry of Science and Innovation. Available online: https:\/\/www.bedca.net\/bdpub\/."},{"key":"ref_19","unstructured":"(2025, October 12). Research Center for Endocrinology and Clinical Nutrition: Diet Calibrator. Available online: https:\/\/calcdieta.ienva.org\/tu_menu.php."},{"key":"ref_20","unstructured":"Siegel, S., and Castellam, N.J. (1988). Nonparametric Statistics for the Behavioral Sciences, McGraw-Hill. [2nd ed.]."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Altman, D.G. (1991). Practical Statistics for Medical Research, Chapman and Hall.","DOI":"10.1201\/9780429258589"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Olza, J., Aranceta-Bartrina, J., Gonz\u00e1lez-Cross, M., Ortega, R., Serra-Majem, L., Varela-Moreiras, G., and Gil, \u00c1. (2017). Reported dietary intake, disparity between the reported consumption and the level needed for adequacy and food sources of calcium, phosphorus, magnesium and vitamin D in the spanish population: Findings from the ANIBES study. Nutrients, 9.","DOI":"10.3390\/nu9020168"},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Calvo, M.S., Dunford, E.K., and Uribarri, J. (2023). Industrial Use of Phosphate Food Additives: A Mechanism Linking Ultra-Processed Food Intake to Cardiorenal Disease Risk?. Nutrients, 15.","DOI":"10.3390\/nu15163510"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"542","DOI":"10.1053\/j.ajkd.2018.11.004","article-title":"Dietary Phosphate and the Forgotten Kidney Patient: A Critical Need for FDA Regulatory Action","volume":"73","author":"Calvo","year":"2019","journal-title":"Am. J. Kidney Dis."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"481","DOI":"10.1097\/MNH.0b013e3283621310","article-title":"The role of the gastrointestinal tract in phosphate homeostasis in health and chronic kidney disease","volume":"22","author":"Marks","year":"2013","journal-title":"Curr. Opin. Nephrol. Hypertens"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Ruiz, E., Avila, J., Valero, T., del Pozo, S., Rodriguez, P., Aranceta-Bartrina, J., Gil, \u00c1., Gonz\u00e1lez-Gross, M., Ortega, R.M., and Serra-Majem, L. (2016). Macronutrient distribution and dietary sources in the Spanish population: Findings from the ANIBES study. Nutrients, 8.","DOI":"10.3390\/nu8030177"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1202","DOI":"10.2215\/CJN.11181012","article-title":"24-Hour Urine Phosphorus Excretion and Mortality and Cardiovascular Events","volume":"8","author":"Palomino","year":"2013","journal-title":"Clin. J. Am. Soc. Nephrol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"176","DOI":"10.1038\/ki.2015.284","article-title":"Relationship of dietary phosphate intake with risk of end-stage renal disease and mortality in chronic kidney disease stages 3\u20135: The Modification of Diet in Renal Disease Study","volume":"89","author":"Selamet","year":"2016","journal-title":"Kidney Int."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1392","DOI":"10.3945\/ajcn.114.085498","article-title":"Effect of dietary phosphate intake on the circadian rhythm of serum phosphate concentrations in chronic kidney disease: A crossover study","volume":"100","author":"Ix","year":"2014","journal-title":"Am. J. Clin. Nutr."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1002","DOI":"10.2215\/CJN.00390118","article-title":"Twenty-Four-Hour Urine Phosphorus as a Biomarker of Dietary Phosphorus Intake and Absorption in CKD: A Secondary Analysis from a Controlled Diet Balance Study","volume":"13","author":"Stremke","year":"2018","journal-title":"Clin. J. Am. Soc. Nephrol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"582","DOI":"10.1159\/000371498","article-title":"The Effect of a Diet Containing 70% Protein from Plants on Mineral Metabolism and Musculoskeletal Health in Chronic Kidney Disease","volume":"40","author":"Moorthi","year":"2014","journal-title":"Am. J. Nephrol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"150","DOI":"10.1053\/j.ackd.2012.10.008","article-title":"Sodium- and Phosphorus-Based Food Additives: Persistent but Surmountable Hurdles in the Management of Nutrition in Chronic Kidney Disease","volume":"20","year":"2013","journal-title":"Adv. Chronic Kidney Dis."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"S1","DOI":"10.1053\/j.ajkd.2020.05.006","article-title":"KDOQI Clinical Practice Guideline for Nutrition in CKD: 2020 update","volume":"76","author":"Burrowes","year":"2020","journal-title":"Am. J. Kidney Dis."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1723","DOI":"10.1681\/ASN.V3111723","article-title":"Dietary protein and renal function","volume":"3","author":"King","year":"1993","journal-title":"J. Am. Soc. Nephrol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1331","DOI":"10.1038\/ki.2010.550","article-title":"Lower estimated glomerular filtration rate and higher albuminuria are associated with mortality and end-stage renal disease. A collaborative meta-analysis of kidney diseasepopulation cohorts","volume":"79","author":"Astor","year":"2011","journal-title":"Kidney Int."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"579","DOI":"10.1681\/ASN.2017070772","article-title":"Longitudinal FGF23 Trajectories and Mortality in Patients with CKD","volume":"29","author":"Isakova","year":"2018","journal-title":"J. Am. Soc. Nephrol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"15","DOI":"10.3390\/ijerph8010015","article-title":"Blocked randomization with randomly selected block sizes","volume":"8","author":"Efird","year":"2011","journal-title":"Int. J. Environ. Res. Public Health"},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Guo, Y., Logan, H.L., Glueck, D.H., and Muller, K.E. (2013). Selecting a sample size for studies with repeated measures. BMC Med. Res. Methodol., 13.","DOI":"10.1186\/1471-2288-13-100"}],"container-title":["Nutrients"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-6643\/17\/21\/3323\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,29]],"date-time":"2025-10-29T02:29:50Z","timestamp":1761704990000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-6643\/17\/21\/3323"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,10,22]]},"references-count":38,"journal-issue":{"issue":"21","published-online":{"date-parts":[[2025,11]]}},"alternative-id":["nu17213323"],"URL":"https:\/\/doi.org\/10.3390\/nu17213323","relation":{},"ISSN":["2072-6643"],"issn-type":[{"type":"electronic","value":"2072-6643"}],"subject":[],"published":{"date-parts":[[2025,10,22]]}}}