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Recognition of the potentially serious implications of this finding led to the identification of a pancreatic tumour which, by the time of diagnosis, had become too advanced for active management. We describe the metabolism of vitamin B12 in the context of hypervitaminosis B12 as a reflection of elevated transcobalamin consequent to underlying disease and the need to identify promptly the underlying cause.<\/jats:p>","DOI":"10.1136\/bcr-2024-262737","type":"journal-article","created":{"date-parts":[[2025,2,11]],"date-time":"2025-02-11T12:47:06Z","timestamp":1739278026000},"page":"e262737","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":1,"title":["Hypervitaminosis B12: an indicator of potential significant morbidity"],"prefix":"10.1136","volume":"18","author":[{"given":"Muzammil Munnawar","family":"Saeed","sequence":"first","affiliation":[{"name":"Respiratory Medicine, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0099-7918","authenticated-orcid":false,"given":"David","family":"Parr","sequence":"additional","affiliation":[{"name":"Respiratory Medicine, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2025,2,11]]},"reference":[{"key":"2025082702550388000_18.2.e262737.1","doi-asserted-by":"publisher","DOI":"10.3390\/nu2030299"},{"key":"2025082702550388000_18.2.e262737.2","doi-asserted-by":"publisher","DOI":"10.1258\/000456303321016187"},{"key":"2025082702550388000_18.2.e262737.3","doi-asserted-by":"crossref","first-page":"4476","DOI":"10.3390\/nu14214476","article-title":"High Plasma Vitamin B12 and Cancer in Human Studies: A Scoping Review to Judge Causality and Alternative Explanations","volume":"14","author":"Obeid","year":"2022","journal-title":"Nutrients"},{"key":"2025082702550388000_18.2.e262737.4","doi-asserted-by":"publisher","DOI":"10.1093\/qjmed\/hct051"},{"key":"2025082702550388000_18.2.e262737.5","doi-asserted-by":"crossref","DOI":"10.1371\/journal.pone.0045979","article-title":"Cobalamin related parameters and disease patterns in patients with increased serum cobalamin levels","volume":"7","author":"Arendt","year":"2012","journal-title":"PLoS One"},{"key":"2025082702550388000_18.2.e262737.6","doi-asserted-by":"crossref","first-page":"2220","DOI":"10.1111\/jgs.13687","article-title":"Hypervitaminosis B12 As an Additional Prognostic Indicator in Elderly Adults with a Neoplastic Disease: Report of a Case and Review of the Literature","volume":"63","author":"Zulfiqar","year":"2015","journal-title":"J American Geriatrics Society"},{"key":"2025082702550388000_18.2.e262737.7","doi-asserted-by":"crossref","first-page":"1330","DOI":"10.7150\/jca.18274","article-title":"Overexpression of Transcobalamin 1 is an Independent Negative Prognosticator in Rectal Cancers Receiving Concurrent Chemoradiotherapy","volume":"8","author":"Lee","year":"2017","journal-title":"J Cancer"},{"key":"2025082702550388000_18.2.e262737.8","doi-asserted-by":"crossref","first-page":"13361","DOI":"10.1038\/s41598-021-92945-y","article-title":"Persistent elevation of plasma vitamin B12 is strongly associated with solid cancer","volume":"11","author":"Lacombe","year":"2021","journal-title":"Sci Rep"},{"key":"2025082702550388000_18.2.e262737.9","doi-asserted-by":"crossref","first-page":"72","DOI":"10.1016\/j.ejso.2010.11.001","article-title":"Haptocorrin as marker of disease progression in fibrolamellar hepatocellular carcinoma","volume":"37","author":"Lildballe","year":"2011","journal-title":"EJSO"},{"key":"2025082702550388000_18.2.e262737.10","doi-asserted-by":"publisher","DOI":"10.1038\/bjc.2017.118"},{"key":"2025082702550388000_18.2.e262737.11","doi-asserted-by":"publisher","DOI":"10.1016\/S0885-3924(00)00169-X"},{"key":"2025082702550388000_18.2.e262737.12","doi-asserted-by":"publisher","DOI":"10.1111\/j.1532-5415.2010.02721.x"},{"key":"2025082702550388000_18.2.e262737.13","doi-asserted-by":"publisher","DOI":"10.1111\/bjh.12959"},{"key":"2025082702550388000_18.2.e262737.14","doi-asserted-by":"crossref","first-page":"365","DOI":"10.1046\/j.1365-2257.2001.00134.x","article-title":"High serum cobalamin levels in the clinical setting - clinical associations and holo-transcobalamin changes","volume":"23","author":"Carmel","year":"2001","journal-title":"Clinical & Laboratory Haematology"},{"key":"2025082702550388000_18.2.e262737.15","unstructured":"National Institute for Health and Care Excellence (NICE) . 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