{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,27]],"date-time":"2026-04-27T20:32:20Z","timestamp":1777321940137,"version":"3.51.4"},"reference-count":33,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2026,4,27]],"date-time":"2026-04-27T00:00:00Z","timestamp":1777248000000},"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>Background\/Objectives: The prevalence of allergic diseases has markedly increased in developed countries, with environmental and dietary factors considered important contributors. Folic acid is an essential micronutrient involved in one-carbon metabolism and DNA methylation, playing a key role in epigenetic regulation of immune function. Both high and low folate exposure have been associated with allergic outcomes, but the data on postnatal folate status in paediatric populations remain limited. This study aimed at assessing serum folate status in children with atopic diseases compared with children without chronic allergic disease in Croatia. Methods: This cross-sectional study included 292 paediatric patients from the University Hospital in Split and a paediatric primary care practice between January 2024 and January 2025. Serum folic acid concentrations were measured using electrochemiluminescence immunoassay. Additional laboratory parameters included vitamin B12, total IgE levels, and eosinophil counts. Demographic and clinical data were obtained from medical records. Statistical analyses included Chi-square tests, Mann\u2013Whitney U tests, linear regression modelling, and analysis of covariance with statistical significance set at p &lt; 0.05. Results: Folic acid deficiency was present in 66.4% of all participants. Children with atopic diseases were significantly more likely to have folate deficiency and had lower mean serum folate concentrations compared to children without allergic disease. There were no significant differences in folate levels between children with and without asthma. Lower folate levels were associated with higher IgE levels, higher eosinophil counts, and older age. When controlling for the effects of age on folic acid levels, the differences between participants with and without atopic diseases remained significant. Conclusions: Folic acid deficiency is highly prevalent among children in the Mediterranean region of Croatia and is significantly associated with atopic diseases and markers of allergic inflammation. These findings highlight a potential role of folate status in paediatric allergic disease and support the need for longitudinal studies to clarify causality and potential clinical implications.<\/jats:p>","DOI":"10.3390\/nu18091368","type":"journal-article","created":{"date-parts":[[2026,4,27]],"date-time":"2026-04-27T19:24:51Z","timestamp":1777317891000},"page":"1368","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Folic Acid Level of Children with Atopy\/Asthma and Children Without Chronic Allergic Disease\u2014Should We Consider Nutritional Fortification?"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4677-9622","authenticated-orcid":false,"given":"Marijana","family":"Rogulj","sequence":"first","affiliation":[{"name":"Department of Paediatrics, University Hospital of Split, Spinciceva 1, 21000 Split, Croatia"},{"name":"School of Medicine, University of Split, 21000 Split, Croatia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4951-0592","authenticated-orcid":false,"given":"Karolina","family":"Mali\u0107 Tudor","sequence":"additional","affiliation":[{"name":"Department of Paediatrics, University Hospital of Split, Spinciceva 1, 21000 Split, Croatia"},{"name":"School of Medicine, University of Split, 21000 Split, Croatia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tina","family":"Brali\u0107","sequence":"additional","affiliation":[{"name":"Department of Paediatrics, University Hospital of Split, Spinciceva 1, 21000 Split, Croatia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jelena","family":"Juki\u0107 Gu\u0107","sequence":"additional","affiliation":[{"name":"Health Center of Split-Dalmatia Conty, Kavanjinova 2, 21000 Split, Croatia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3801-1026","authenticated-orcid":false,"given":"Marin","family":"Ogorevc","sequence":"additional","affiliation":[{"name":"Department of Pathology, Forensic Medicine and Cytology, University Hospital of Split, Spinciceva 1, 21000 Split, Croatia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Josipa","family":"\u0106ubeli\u0107","sequence":"additional","affiliation":[{"name":"Department of Paediatrics, University Hospital of Split, Spinciceva 1, 21000 Split, Croatia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Snje\u017eana","family":"Kapor Jeri\u010devi\u0107","sequence":"additional","affiliation":[{"name":"Paediatric Clinic, Trh Hrvatske Bratske Zajednice 4, 21000 Split, Croatia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,4,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1253","DOI":"10.1016\/j.jaci.2009.03.007","article-title":"Higher serum folate levels are associated with a lower risk of atopy and wheeze","volume":"123","author":"Matsui","year":"2009","journal-title":"J. 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