{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T21:32:12Z","timestamp":1789680732562,"version":"4.0.1"},"reference-count":23,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2023,3,6]],"date-time":"2023-03-06T00:00:00Z","timestamp":1678060800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Background: Vitamin B12 (cobalamin CBL) is a water-soluble vitamin required to form hematopoietic cells (red blood cells, white blood cells, and platelets). It is involved in the process of synthesizing DNA and myelin sheath. Deficiencies of vitamin B12 and\/or folate can cause megaloblastic anemia (macrocytic anemia with other features due to impaired cell division). Pancytopenia is a less frequent exordium of severe vitamin B12 deficiency. Vitamin B12 deficiency can also cause neuropsychiatric findings. In addition to correcting the deficiency, an essential aspect of management is determining the underlying cause because the need for additional testing, the duration of therapy, and the route of administration may differ depending on the underlying cause. Methods: Here, we present a series of four patients hospitalized for megaloblastic anemia (MA) in pancytopenia. All patients diagnosed with MA were studied for a clinic-hematological and etiological profile. Results: All the patients presented with pancytopenia and megaloblastic anemia. Vitamin B12 deficiency was documented in 100% of cases. There was no correlation between the severity of anemia and deficiency of the vitamin. Overt clinical neuropathy was present in none of the cases of MA, while subclinical neuropathy was seen in one case. The etiology of vitamin B12 deficiency was pernicious anemia in two cases and low food intake in the remaining cases. Conclusion: This case study emphasizes the role of vitamin B12 deficiency as a leading cause of pancytopenia among adults.<\/jats:p>","DOI":"10.3390\/jcm12052059","type":"journal-article","created":{"date-parts":[[2023,3,6]],"date-time":"2023-03-06T02:28:34Z","timestamp":1678069714000},"page":"2059","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Pancytopenia Secondary to Vitamin B12 Deficiency in Older Subjects"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2269-0439","authenticated-orcid":false,"given":"Giulia","family":"Costanzo","sequence":"first","affiliation":[{"name":"S.C. di Medicina Interna, Policlinico Universitario Monserrato \u201cDuilio Casula\u201d\u2014AOU di Cagliari, 09123 Cagliari, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Giada","family":"Sambugaro","sequence":"additional","affiliation":[{"name":"Scuola Specializzazione Allergologia e Immunologia Clinica, Universita\u2019 di Cagliari, 09124 Cagliari, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Giulia","family":"Mandis","sequence":"additional","affiliation":[{"name":"Scuola Specializzazione Medicina Interna, Universita\u2019 di Cagliari, 09124 Cagliari, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sofia","family":"Vassallo","sequence":"additional","affiliation":[{"name":"Scuola Specializzazione Allergologia e Immunologia Clinica, Universita\u2019 di Cagliari, 09124 Cagliari, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4784-5441","authenticated-orcid":false,"given":"Angelo","family":"Scuteri","sequence":"additional","affiliation":[{"name":"S.C. di Medicina Interna, Policlinico Universitario Monserrato \u201cDuilio Casula\u201d\u2014AOU di Cagliari, 09123 Cagliari, Italy"},{"name":"Dipartimento Scienze Mediche e Sanita\u2019 Pubblica, Universita\u2019 di Cagliari, 09124 Cagliari, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,3,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1093\/ageing\/30.2.115","article-title":"Nutritional assessment: A simple step forward","volume":"30","author":"Reynish","year":"2001","journal-title":"Age Ageing"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"M725","DOI":"10.1093\/gerona\/55.12.M725","article-title":"Nutritional management in long-term care: Development of a clinical guideline. Council for nutritional strategies in long-term care","volume":"55","author":"Thomas","year":"2000","journal-title":"J. Gerontol. A Biol. Sci. Med. Sci."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1477","DOI":"10.1007\/s40520-020-01656-3","article-title":"Prognostic value of geriatric nutritional risk index in elderly patients with heart failure: A meta-analysis","volume":"33","author":"Li","year":"2021","journal-title":"Aging Clin. Exp. Res."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"653182","DOI":"10.4061\/2011\/653182","article-title":"Metabolic syndrome, chronic kidney, and cardiovascular diseases: Role of adipokines","volume":"2011","author":"Tesauro","year":"2011","journal-title":"Cardiol. Res. Pract."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1493","DOI":"10.1007\/s40520-020-01674-1","article-title":"Incidence and associated factors of delirium after orthopedic surgery in elderly patients: A systematic review and meta-analysis","volume":"33","author":"Yang","year":"2021","journal-title":"Aging Clin. Exp. Res."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"677","DOI":"10.1007\/s12603-019-1215-9","article-title":"The Relationship between Nutritional Status, Anemia and Other Vitamin Deficiencies in the Elderly Receiving Home Care","volume":"23","author":"Emiroglu","year":"2019","journal-title":"J. Nutr. Health Aging"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2211","DOI":"10.1007\/s40520-019-01454-6","article-title":"Predictors of iron-deficiency anemia in primary care older adults: A real-world European multi-country longitudinal study","volume":"32","author":"Vetrano","year":"2020","journal-title":"Aging Clin. Exp. Res."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"857","DOI":"10.1007\/s40520-015-0490-5","article-title":"Prevalence of anemia and malnutrition and their association in elderly nursing home residents","volume":"28","author":"Sahin","year":"2016","journal-title":"Aging Clin. Exp. Res."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Hoenemann, C., Ostendorf, N., Zarbock, A., Doll, D., Hagemann, O., Zimmermann, M., and Luedi, M. (2021). Reticulocyte and Erythrocyte Hemoglobin Parameters for Iron Deficiency and Anemia Diagnostics in Patient Blood Management. A Narrative Review. J. Clin. Med., 10.","DOI":"10.3390\/jcm10184250"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1016\/j.maturitas.2016.04.020","article-title":"Association between hematologic parameters and functional impairment among geriatric inpatients: Data of a prospective cross-sectional multicenter study (\u201cGeriPr\u00e4valenz2013\u201d)","volume":"90","author":"Becker","year":"2016","journal-title":"Maturitas"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"278","DOI":"10.1016\/j.neurobiolaging.2005.02.007","article-title":"Anemia increases the risk of dementia in cognitively intact elderly","volume":"27","author":"Atti","year":"2006","journal-title":"Neurobiol. Aging"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2849","DOI":"10.1007\/s40520-019-01387-0","article-title":"The appropriateness of antiplatelet and anticoagulant drug prescriptions in hospitalized patients in an internal medicine ward","volume":"33","author":"Manzocco","year":"2021","journal-title":"Aging Clin. Exp. Res."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"619","DOI":"10.1007\/s00391-015-0872-5","article-title":"Association of anemia and hypoalbuminemia in German geriatric inpatients: Relationship to nutritional status and comprehensive geriatric assessment","volume":"48","author":"Becker","year":"2015","journal-title":"Z. Gerontol. Geriatr."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1016\/S0531-5565(98)00055-2","article-title":"Aging and red blood cell membrane: A study of centenarians","volume":"34","author":"Caprari","year":"1999","journal-title":"Exp. Gerontol."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Lenti, M.V., Lahner, E., Bergamaschi, G., Miceli, E., Conti, L., Massironi, S., Cococcia, S., Zilli, A., Caprioli, F., and Vecchi, M. (2019). Cell Blood Count Alterations and Patterns of Anaemia in Autoimmune Atrophic Gastritis at Diagnosis: A Multicentre Study. J. Clin. Med., 8.","DOI":"10.3390\/jcm8111992"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"149","DOI":"10.1056\/NEJMcp1113996","article-title":"Clinical practice. Vitamin B12 deficiency","volume":"368","author":"Stabler","year":"2013","journal-title":"N. Engl. J. Med."},{"key":"ref_17","first-page":"4617","article-title":"Apoptosis of late-stage erythroblasts in megaloblastic anemia: Association with DNA damage and macrocyte production","volume":"89","author":"Koury","year":"1997","journal-title":"Blood J. Am. Soc. Hematol."},{"key":"ref_18","first-page":"15","article-title":"Further characterization of the erythrocyte membrane protein abnormality in megaloblastic anemia","volume":"13","author":"Ballas","year":"1982","journal-title":"J. Med."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"898","DOI":"10.7326\/0003-4819-53-5-898","article-title":"Enzymes in anemia: A study of abnormalities of several enzymes of carbohvdrate metabolism in the plasma and erythrocytes in patients with anemia, with preliminary observations of bone marrow enzymes","volume":"53","author":"Heller","year":"1960","journal-title":"Ann. Intern. Med."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"241","DOI":"10.1111\/j.1600-0609.1978.tb02453.x","article-title":"Serum ferritin in megaloblastic anaemia","volume":"20","author":"Hussein","year":"1978","journal-title":"Scand. J. Haematol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"246","DOI":"10.1111\/j.1600-0609.1992.tb00056.x","article-title":"Serum transferrin receptor in the megaloblastic anemia of cobalamin deficiency","volume":"49","author":"Carmel","year":"1992","journal-title":"Eur. J. Haematol."},{"key":"ref_22","first-page":"2603","article-title":"Vitamin B12 deficiency from the perspective of a practicing hematologist","volume":"129","author":"Green","year":"2017","journal-title":"Blood J. Am. Soc. Hematol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"17562848211038771","DOI":"10.1177\/17562848211038771","article-title":"Autoimmune gastritis, with or without pernicious anemia: Epidemiology, risk factors, and clinical management","volume":"14","author":"Rustgi","year":"2021","journal-title":"Ther. Adv. Gastroenterol."}],"container-title":["Journal of Clinical Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2077-0383\/12\/5\/2059\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T18:48:41Z","timestamp":1760122121000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2077-0383\/12\/5\/2059"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,3,6]]},"references-count":23,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2023,3]]}},"alternative-id":["jcm12052059"],"URL":"https:\/\/doi.org\/10.3390\/jcm12052059","relation":{},"ISSN":["2077-0383"],"issn-type":[{"value":"2077-0383","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,3,6]]}}}