{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,2]],"date-time":"2026-10-02T23:31:26Z","timestamp":1790983886490,"version":"4.1.0"},"reference-count":50,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2026,5,5]],"date-time":"2026-05-05T00:00:00Z","timestamp":1777939200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100009553","name":"AZV grant project","doi-asserted-by":"publisher","award":["NU22-07-00126"],"award-info":[{"award-number":["NU22-07-00126"]}],"id":[{"id":"10.13039\/501100009553","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Institutional support program","award":["RVO VFN64165"],"award-info":[{"award-number":["RVO VFN64165"]}]},{"name":"Charles University COOPERATIO program"},{"id":[{"id":"https:\/\/ror.org\/024d6js02","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJNS"],"abstract":"<jats:p>Neonatal vitamin B12 (B12) deficiency can cause neurodevelopmental harm, and newborn screening (NBS) may enable early detection and treatment. We conducted a multicenter pilot project in four Prague university hospitals between 1 June 2022 and 30 June 2025. Algorithms included the determination of propionylcarnitine-derived primary markers using flow-injection tandem mass spectrometry and second-tier methylmalonic acid (MMA), with total homocysteine measured only when MMA was increased. Of 34,302 screened newborns with consent, 1365 (3.98%) triggered second-tier testing; 9 had MMA &gt; 2.5 \u00b5mol\/L, of which 8 met the case definition after confirmatory testing, giving a birth frequency of 1:4228 (95% CI 1:2176\u20131:9931). Positive predictive value was 0.59% (95% CI 0.25\u20131.15%) and 88.89% (95% CI 51.75\u201399.72%) for the primary test and second-tier MMA, respectively, with a false positive rate of 0.00292% (95% CI 0.000074\u20130.01625%). All affected infants were treated orally with cyanocobalamin. Maternal work-up identified confirmed B12 deficiency in four of eight mothers and premalignant gastric changes in two of four positive women. These data support the feasibility, low cost, and clinical utility of incorporating B12 deficiency into Czech NBS, with benefits extending beyond newborn health.<\/jats:p>","DOI":"10.3390\/ijns12020030","type":"journal-article","created":{"date-parts":[[2026,5,6]],"date-time":"2026-05-06T07:36:23Z","timestamp":1778052983000},"page":"30","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Pilot Newborn Screening for Vitamin B12 Deficiency in the Czech Republic: Results and Detailed Studies on Identified Babies and Their Mothers"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0009-0005-2188-7936","authenticated-orcid":false,"given":"Samuel","family":"Stanovsk\u00fd","sequence":"first","affiliation":[{"name":"Department of Pediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital, 128 08 Prague, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Josef","family":"B\u00e1rtl","sequence":"additional","affiliation":[{"name":"Department of Pediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital, 128 08 Prague, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4404-6513","authenticated-orcid":false,"given":"Petr","family":"Chrastina","sequence":"additional","affiliation":[{"name":"Department of Pediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital, 128 08 Prague, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5820-5277","authenticated-orcid":false,"given":"Viktor","family":"Ko\u017eich","sequence":"additional","affiliation":[{"name":"Department of Pediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital, 128 08 Prague, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jakub","family":"Krijt","sequence":"additional","affiliation":[{"name":"Department of Pediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital, 128 08 Prague, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Krist\u00fdna","family":"Nelicov\u00e1","sequence":"additional","affiliation":[{"name":"Department of Pediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital, 128 08 Prague, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0453-3336","authenticated-orcid":false,"given":"Jitka","family":"Sokolov\u00e1","sequence":"additional","affiliation":[{"name":"Department of Pediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital, 128 08 Prague, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6840-283X","authenticated-orcid":false,"given":"Truong An","family":"Nguyen","sequence":"additional","affiliation":[{"name":"Department of Gynecology, Obstetrics and Neonatology, First Faculty of Medicine, Charles University and General University Hospital, 128 08 Prague, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Richard","family":"Plavka","sequence":"additional","affiliation":[{"name":"Department of Gynecology, Obstetrics and Neonatology, First Faculty of Medicine, Charles University and General University Hospital, 128 08 Prague, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kv\u011bta","family":"Pelinkov\u00e1","sequence":"additional","affiliation":[{"name":"Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University and General University Hospital, 128 08 Prague, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4756-0585","authenticated-orcid":false,"given":"Drahom\u00edra","family":"Springer","sequence":"additional","affiliation":[{"name":"Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University and General University Hospital, 128 08 Prague, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kl\u00e1ra","family":"Berkov\u00e1","sequence":"additional","affiliation":[{"name":"Department of Neonatology, Third Faculty of Medicine, Charles University and Institute for the Care of Mother and Child, 147 00 Prague, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7095-3198","authenticated-orcid":false,"given":"Zbyn\u011bk","family":"Stra\u0148\u00e1k","sequence":"additional","affiliation":[{"name":"Department of Neonatology, Third Faculty of Medicine, Charles University and Institute for the Care of Mother and Child, 147 00 Prague, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0684-375X","authenticated-orcid":false,"given":"Jan","family":"Janota","sequence":"additional","affiliation":[{"name":"Neonatal Unit, Motol and Homolka University Hospital, 150 06 Prague, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Katar\u00edna","family":"Tich\u00e1","sequence":"additional","affiliation":[{"name":"Neonatal Unit, Motol and Homolka University Hospital, 150 06 Prague, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ji\u0159\u00ed","family":"Zach","sequence":"additional","affiliation":[{"name":"Neonatal Unit, Thomayer University Hospital, 140 59 Prague, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tom\u00e1\u0161","family":"Honz\u00edk","sequence":"additional","affiliation":[{"name":"Department of Pediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital, 128 08 Prague, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,5,5]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"106","DOI":"10.1093\/nutrit\/nuu011","article-title":"Vitamin B12 in Meat and Dairy Products","volume":"73","author":"Gille","year":"2015","journal-title":"Nutr. 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