{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T12:17:27Z","timestamp":1791980247895,"version":"4.4.0"},"reference-count":37,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2022,11,4]],"date-time":"2022-11-04T00:00:00Z","timestamp":1667520000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"JST\/RISTEX"},{"name":"JST\/CREST"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nutrients"],"abstract":"<jats:p>The findings regarding whether the greater iron level or intake is a risk factor to Parkinson\u2019s disease (PD) or parkinsonism was not clear. The purpose of this study is to establish a consistent association between iron supplementation and parkinsonism risk, we conducted a large-scale prospective cohort study using comprehensive longitudinal data from the UK Biobank. The longitudinal cohort data of 385,898 participants (including 911 cases) who were middle to old aged British adults and joined the UK Biobank study from 2006 to 2010 and were followed up until 2018 was analyzed. The associations between iron supplement intake, hemoglobin levels and all cause subsequent parkinsonism risk after corrections of potential confounders (sex, age, household income, education length, employment status, deprivation level, body mass index, physical activity level, household numbers, smoking and drinking levels, health status, blood pressure) were investigated. Analyses revealed that (a) iron supplementation was significantly associated with higher parkinsonism risk, (b) greater hemoglobin was weakly and insignificantly associated with lower parkinsonism risk, and (c) multivitamin or vitamin C supplement intake was not significantly associated with parkinsonism risk. Regardless of whether the subjects were classified as anemic, normal, or polycythemic or in the hemoglobin level quintile, there was no nonlinear association between hemoglobin and parkinsonism risk. Parkinsonism risk did not differ between participants reporting supplementary iron intake with or without vitamin C or multivitamin supplement intake. Furthermore, polygenic risk score of PD negatively correlated with hemoglobin level, while it did not associate with intake of iron supplement or multivitamin or vitamin C supplement intake. The results suggest excessive iron intake may increase parkinsonism risk. Interventional studies are warranted to examine whether iron intake restriction is beneficial for individuals without clinical iron deficiency.<\/jats:p>","DOI":"10.3390\/nu14214671","type":"journal-article","created":{"date-parts":[[2022,11,4]],"date-time":"2022-11-04T09:23:37Z","timestamp":1667553817000},"page":"4671","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["A Prospective Study on the Relationship between Iron Supplement Intake, Hemoglobin Concentration, and Risk of Parkinsonism"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8022-9694","authenticated-orcid":false,"given":"Hikaru","family":"Takeuchi","sequence":"first","affiliation":[{"name":"Division of Developmental Cognitive Neuroscience, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-cho, Aoba-ku, Sendai 980-8575, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ryuta","family":"Kawashima","sequence":"additional","affiliation":[{"name":"Division of Developmental Cognitive Neuroscience, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-cho, Aoba-ku, Sendai 980-8575, Japan"},{"name":"Smart Aging Research Center, Tohoku University, Sendai 980-8575, Japan"},{"name":"Department of Advanced Brain Science, Institute of Development, Aging and Cancer, Tohoku University, Sendai 980-8575, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,11,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"802","DOI":"10.1016\/j.amjmed.2019.03.001","article-title":"Parkinson\u2019s disease and parkinsonism","volume":"132","author":"Hayes","year":"2019","journal-title":"Am. J. Med."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1136\/jnnp.62.1.10","article-title":"Prevalence of parkinsonism and Parkinson\u2019s disease in Europe: The EUROPARKINSON Collaborative Study. European Community Concerted Action on the Epidemiology of Parkinson\u2019s disease","volume":"62","author":"Tzourio","year":"1997","journal-title":"J. Neurol. Neurosurg. Psychiatry"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"389","DOI":"10.1002\/ana.21022","article-title":"Genetics of Parkinson\u2019s disease and parkinsonism","volume":"60","author":"Hardy","year":"2006","journal-title":"Ann. Neurol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"96","DOI":"10.1016\/j.pneurobio.2015.09.012","article-title":"Interactions of iron, dopamine and neuromelanin pathways in brain aging and Parkinson\u2019s disease","volume":"155","author":"Zucca","year":"2017","journal-title":"Prog. Neurobiol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1007\/978-981-13-9589-5_4","article-title":"Iron pathophysiology in Parkinson diseases","volume":"1173","author":"Jiang","year":"2019","journal-title":"Brain Iron Metab. CNS Dis."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1038\/nm.4269","article-title":"\u03b1-synuclein toxicity in neurodegeneration: Mechanism and therapeutic strategies","volume":"23","author":"Wong","year":"2017","journal-title":"Nat. Med."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"253","DOI":"10.1016\/j.freeradbiomed.2019.06.024","article-title":"Interactions between iron and \u03b1-synuclein pathology in Parkinson\u2019s disease","volume":"141","author":"Chen","year":"2019","journal-title":"Free Radic. Biol. Med."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"461","DOI":"10.1021\/acs.biomac.6b01547","article-title":"Iron chelation nanoparticles with delayed saturation as an effective therapy for Parkinson disease","volume":"18","author":"Wang","year":"2017","journal-title":"Biomacromolecules"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"6405278","DOI":"10.1155\/2017\/6405278","article-title":"Role of diet and nutritional supplements in Parkinson\u2019s disease progression","volume":"2017","author":"Mischley","year":"2017","journal-title":"Oxid. Med. Cell. Longev."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Pichler, I., Del Greco, M.F., G\u00f6gele, M., Lill, C.M., Bertram, L., Do, C.B., Eriksson, N., Foroud, T., Myers, R.H., and Consortium, P.G. (2013). Serum iron levels and the risk of Parkinson disease: A Mendelian randomization study. PLoS Med., 10.","DOI":"10.1371\/annotation\/c4d81646-0c0e-4a3e-9425-b220bae2d8b6"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1381","DOI":"10.1212\/WNL.0b013e3181bd80c1","article-title":"Anemia or low hemoglobin levels preceding Parkinson disease: A case-control study","volume":"73","author":"Savica","year":"2009","journal-title":"Neurology"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"29651","DOI":"10.1038\/srep29651","article-title":"Newly diagnosed anemia increases risk of Parkinson\u2019s disease: A population-based cohort study","volume":"6","author":"Hong","year":"2016","journal-title":"Sci. Rep."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Zhukovskaya, E., Karelin, A., and Rumyantsev, A. (2019). Neurocognitive dysfunctions in iron deficiency patients. Iron Deficiency Anemia, IntechOpen.","DOI":"10.5772\/intechopen.82620"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2269","DOI":"10.1007\/s10072-015-2349-0","article-title":"Dietary intake of iron, zinc, copper, and risk of Parkinson\u2019s disease: A meta-analysis","volume":"36","author":"Cheng","year":"2015","journal-title":"Neurol. Sci."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1761","DOI":"10.1212\/01.WNL.0000068021.13945.7F","article-title":"Parkinson\u2019s disease risks associated with dietary iron, manganese, and other nutrient intakes","volume":"60","author":"Powers","year":"2003","journal-title":"Neurology"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1016\/j.parkreldis.2008.03.002","article-title":"Dietary fats, cholesterol and iron as risk factors for Parkinson\u2019s disease","volume":"15","author":"Powers","year":"2009","journal-title":"Park. Relat. Disord."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1381","DOI":"10.1093\/aje\/kwn273","article-title":"Dietary iron intake and risk of Parkinson\u2019s disease","volume":"168","author":"Logroscino","year":"2008","journal-title":"Am. J. Epidemiol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"324","DOI":"10.1111\/j.1749-6632.1987.tb23771.x","article-title":"Is there a physiological role of vitamin C in iron absorption?","volume":"498","author":"Hallberg","year":"1987","journal-title":"Ann. N. Y. Acad. Sci."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"3870","DOI":"10.1073\/pnas.0912319107","article-title":"Inverted-U-shaped correlation between dopamine receptor availability in striatum and sensation seeking","volume":"107","author":"Gjedde","year":"2010","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Takeuchi, H., and Kawashima, R. (2021). Diet and Dementia: A Prospective Study. Nutrients, 13.","DOI":"10.3390\/nu13124500"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"189","DOI":"10.1038\/s42003-020-0921-5","article-title":"Predicted loss and gain of function mutations in ACO1 are associated with erythropoiesis","volume":"3","author":"Oskarsson","year":"2020","journal-title":"Commun. Biol."},{"key":"ref_22","unstructured":"World Health Organization (1993). Report of the WHO\/UNICEF\/UNU Consultation on Indicators and Strategies for Iron Deficiency and Anemia Programmes, World Health Organization."},{"key":"ref_23","first-page":"232","article-title":"How Does 2016 WHO Criteria for Polycythemia Vera Contribute to Our Daily Practice? A Single-Center Study from Turkey","volume":"14","author":"Eren","year":"2020","journal-title":"Int. J. Hematol.-Oncol. Stem Cell Res."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"430","DOI":"10.1001\/jama.2019.9879","article-title":"Association of lifestyle and genetic risk with incidence of dementia","volume":"322","author":"Lourida","year":"2019","journal-title":"JAMA"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"491","DOI":"10.1093\/biomet\/93.3.491","article-title":"Adaptive linear step-up procedures that control the false discovery rate","volume":"93","author":"Benjamini","year":"2006","journal-title":"Biometrika"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1091","DOI":"10.1016\/S1474-4422(19)30320-5","article-title":"Identification of novel risk loci, causal insights, and heritable risk for Parkinson\u2019s disease: A meta-analysis of genome-wide association studies","volume":"18","author":"Nalls","year":"2019","journal-title":"Lancet Neurol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1219","DOI":"10.1016\/S0140-6736(87)91361-4","article-title":"Increased nigral iron content in postmortem parkinsonian brain","volume":"330","author":"Dexter","year":"1987","journal-title":"Lancet"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1138","DOI":"10.1212\/WNL.45.6.1138","article-title":"Increased iron-related MRI contrast in the substantia nigra in Parkinson\u2019s disease","volume":"45","author":"Gorell","year":"1995","journal-title":"Neurology"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1101","DOI":"10.1016\/S0306-4522(97)00660-X","article-title":"Manganese: A transition metal protects nigrostriatal neurons from oxidative stress in the iron-induced animal model of parkinsonism","volume":"85","author":"Sziraki","year":"1998","journal-title":"Neuroscience"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"25","DOI":"10.1006\/taap.1999.8711","article-title":"Neonatal iron exposure induces neurobehavioural dysfunctions in adult mice","volume":"159","author":"Fredriksson","year":"1999","journal-title":"Toxicol. Appl. Pharmacol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"907","DOI":"10.1016\/j.neurobiolaging.2006.04.003","article-title":"Increased murine neonatal iron intake results in Parkinson-like neurodegeneration with age","volume":"28","author":"Kaur","year":"2007","journal-title":"Neurobiol. Aging"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"110717","DOI":"10.1016\/j.jinorgbio.2019.110717","article-title":"Iron and other metals in the pathogenesis of Parkinson\u2019s disease: Toxic effects and possible detoxification","volume":"199","author":"Hofer","year":"2019","journal-title":"J. Inorg. Biochem."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"179","DOI":"10.1111\/jnc.13425","article-title":"Iron neurochemistry in Alzheimer\u2019s disease and Parkinson\u2019s disease: Targets for therapeutics","volume":"139","author":"Belaidi","year":"2016","journal-title":"J. Neurochem."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"52","DOI":"10.1016\/j.freeradbiomed.2013.01.017","article-title":"Targeting dysregulation of brain iron homeostasis in Parkinson\u2019s disease by iron chelators","volume":"62","author":"Weinreb","year":"2013","journal-title":"Free Radic. Biol. Med."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"863","DOI":"10.1038\/nrn1537","article-title":"Iron, brain ageing and neurodegenerative disorders","volume":"5","author":"Zecca","year":"2004","journal-title":"Nat. Rev. Neurosci."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"568","DOI":"10.1002\/mds.27275","article-title":"Iron as a therapeutic target for Parkinson\u2019s disease","volume":"33","author":"Moreau","year":"2018","journal-title":"Mov. Disord."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"41","DOI":"10.1146\/annurev.nutr.23.020102.075739","article-title":"Iron status and neural functioning","volume":"23","author":"Beard","year":"2003","journal-title":"Annu. Rev. Nutr."}],"container-title":["Nutrients"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-6643\/14\/21\/4671\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:10:36Z","timestamp":1760145036000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-6643\/14\/21\/4671"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,11,4]]},"references-count":37,"journal-issue":{"issue":"21","published-online":{"date-parts":[[2022,11]]}},"alternative-id":["nu14214671"],"URL":"https:\/\/doi.org\/10.3390\/nu14214671","relation":{},"ISSN":["2072-6643"],"issn-type":[{"value":"2072-6643","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,11,4]]}}}