CoChat
Sign Up
Cited by 19Vitamin D Research StudiesNutrition and Health StudiesVitamin K Research Studies

Vitamin D Supplementation: Practical Advice in Different Clinical Settings

Open access
Bendotti, Giulia, Biamonte, Emilia, Leporati, Paola, Goglia, Umberto, Ruggeri, Rosaria Maddalena, Gallo, Marco·2025·Nutrients
DOI 10.3390/nu17050783PMC PMC11901608
Open this paper in CoChat — free account

Abstract

A global deficiency in vitamin D is now widely prevalent. Extensive scientific research has provided compelling evidence of the detrimental effects of vitamin D deficiency on the skeletal system. Furthermore, vitamin D supplementation not only helps prevent bone fractures but may also slow the progression of various conditions, such as diabetes, autoimmune disorders, and cardiovascular disease. Achieving optimal circulating vitamin D levels can be challenging, particularly in certain clinical scenarios. Moreover, the effect of vitamin D supplementation varies depending on factors such as body weight, pregnancy status, absorption capacity, metabolic rate, and renal function. This review aims to explore which vitamin D formulations are most effective in specific clinical contexts where reaching adequate vitamin D levels may not be straightforward.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.3390/nu17050783

Cites

2 of 2 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Supplementation effects depend strongly on baseline vitamin D status, assay standardization, dose, formulation, adherence, and population context.

    “supplementation effects depend strongly on baseline status, assay standardization, dose, formulation, adherence, and population context [1,2,3,4,5,6].”

    From Vitamin D Supplementation, Total Testosterone, and Androgen Bioavailability Markers in Adult Men: A Systematic Review and Meta-Analysis of Randomized Controlled Trials (2026) · cites this paper as [6]

    The Conclusions (section 7) say supplementation efficacy varies across clinical settings and should account for baseline 25(OH)D levels and formulation; the Obesity section (section 2) also discusses baseline levels and dose. The Pregnancy/Breastfeeding section (section 6) identifies adherence as an issue in supplementation strategies. Our copy does not address assay standardization as a factor in supplementation effects, so the full list is not supported by this source. (LLM, conf=0.86)

    Experimental — accuracy not yet measured

  • The present results are consistent with the broader vitamin D trial literature, where extra-skeletal effects often appear weaker in randomized evidence than in observational studies.

    “The present results are consistent with the broader vitamin D trial literature, where extra-skeletal effects often appear weaker in randomized evidence than in observational studies [3,4,5,6].”

    From Vitamin D Supplementation, Total Testosterone, and Androgen Bioavailability Markers in Adult Men: A Systematic Review and Meta-Analysis of Randomized Controlled Trials (2026) · cites this paper as [6]

    Section 2, “Vitamin D and Obesity” (page unavailable), reports an association between low vitamin D levels and obesity, while a meta-analysis of trials found no significant effect of supplementation on weight or fat mass. This illustrates weaker trial findings for one extra-skeletal outcome, but the review does not establish that pattern across extra-skeletal effects generally or explicitly compare randomized with observational evidence across the broader literature. (LLM, conf=0.84)

    Experimental — accuracy not yet measured

  • Vitamin D supplementation effects depend on baseline 25(OH)D status, dose, formulation, adherence, duration, body composition, and whether participants are deficient or already replete at baseline.

    “Vitamin D supplementation effects depend on baseline 25(OH)D status, dose, formulation, adherence, duration, body composition, and whether participants are deficient or already replete at baseline [3,4,5,6].”

    From Vitamin D Supplementation, Total Testosterone, and Androgen Bioavailability Markers in Adult Men: A Systematic Review and Meta-Analysis of Randomized Controlled Trials (2026) · cites this paper as [6]

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

Flagged first, then by citations

Research works printed but not linked: 64

  1. [1]Giustina A. Consensus Statement on Vitamin D Status Assessment and Supplementation: Whys, Whens, and Hows Endocr. Rev. 2024 45 625 654 10.1210/endrev/bnae009 38676447 PMC11405507 · DOI · Paper page
  2. [3]Zmijewski M.A. Vitamin D and Human Health Int. J. Mol. Sci. 2019 20 145 10.3390/ijms20010145 30609781 PMC6337085 · DOI
  3. [4]Fleet J.C. The Role of Vitamin D in the Endocrinology Controlling Calcium Homeostasis Mol. Cell Endocrinol. 2018 453 36 45 10.1016/j.mce.2017.04.008 28400273 PMC5529228 · DOI
  4. [5]Silva I.C.J. Lazaretti-Castro M. Vitamin D metabolism and extraskeletal outcomes: An update Arch. Endocrinol. Metab. 2022 66 748 755 10.20945/2359-3997000000565 36382764 PMC10118817 · DOI
  5. [6]Fu Z. Xu C. Shu Y. Xie Z. Lu C. Mo X. Serum 25-hydroxyvitamin D is associated with obesity and metabolic parameters in US children Public Health Nutr. 2019 23 1214 1222 10.1017/S1368980019001137 31120008 PMC10200621 · DOI
  6. [7]Walsh J.S. Evans A.L. Bowles S. Naylor K.E. Jones K.S. Schoenmakers I. Jacques R.M. Eastell R. Free 25-hydroxyvitamin D is low in obesity, but there are no adverse associations with bone health1–3 Am. J. Clin. Nutr. 2016 103 1465 10.3945/ajcn.115.120139 27169839 · DOI
  7. [8]Pramono A. Jocken J.W.E. Goossens G.H. Blaak E.E. Vitamin D release across abdominal adipose tissue in lean and obese men: The effect of ß-adrenergic stimulation Physiol. Rep. 2019 7 e14308 10.14814/phy2.14308 31872972 PMC6928243 · DOI
  8. [9]Spyksma E.E. Alexandridou A. Mai K. Volmer D.A. Stokes C.S. An Overview of Different Vitamin D Compounds in the Setting of Adiposity Nutrients 2024 16 231 10.3390/nu16020231 38257127 PMC10820956 · DOI
  9. [11]Jodar E. Calcifediol: A review of its pharmacological characteristics and clinical use in correcting vitamin D deficiency Eur. J. Nutr. 2023 62 1579 1597 10.1007/s00394-023-03103-1 36862209 PMC9979899 · DOI
  10. [12]Das L. Impact of BMI on serum 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D with calcifediol supplementation in young adults: A longitudinal study Endocrine 2024 86 391 399 10.1007/s12020-024-03895-0 38861119 · DOI
  11. [13]Elena K. Intakes of Calcium and Vitamin D Predict Body Mass Index in the Population of Northern Norway J. Nutr. 2003 133 102 106 10.1093/jn/133.1.102 12514276 · DOI
  12. [14]Mallard S.R. Howe A.S. Houghton L.A. Vitamin D status and weight loss: A systematic review and meta-analysis of randomized and nonrandomized controlled weight-loss trials Am. J. Clin. Nutr. 2016 104 1151 1159 10.3945/ajcn.116.136879 27604772 · DOI
  13. [15]Pathak K. Soares M.J. Calton E.K. Zhao Y. Hallett J. Vitamin D supplementation and body weight status: A systematic review and meta-analysis of randomized controlled trials Obes. Rev. 2014 15 528 537 10.1111/obr.12162 24528624 · DOI
  14. [16]Golzarand M. Hollis B.W. Mirmiran P. Wagner C.L. Shab-Bidar S. Vitamin D supplementation and body fat mass: A systematic review and meta-analysis Eur. J. Clin. Nutr. 2018 72 1345 1357 10.1038/s41430-018-0132-z 29563638 · DOI
  15. [17]Boucher B.J. Why do so many trials of vitamin D supplementation fail? Endocr. Connect. 2020 9 195 206 10.1530/EC-20-0274 33052876 PMC7487184 · DOI
  16. [18]Pilz S. Trummer C. Theiler-Schwetz V. Grübler M.R. Verheyen N.D. Odler B. Karras S.N. Zittermann A. März W. Critical Appraisal of Large Vitamin D Randomized Controlled Trials Nutrients 2022 14 303 10.3390/nu14020303 35057483 PMC8778517 · DOI
  17. [19]Tobias D.K. Luttmann-Gibson H. Mora S. Danik J. Bubes V. Copeland T. LeBoff M.S. Cook N.R. Lee I.-M. Buring J.E. Association of Body Weight With Response to Vitamin D Supplementation and Metabolism JAMA Netw. Open 2023 6 e2250681 10.1001/jamanetworkopen.2022.50681 36648947 PMC9856931 · DOI
  18. [20]Yu K. Song W. Tu X. Zhou K. Prabahar K. The effect of vitamin D on the lipid profile in individuals with overweight or obesity: A meta-analysis and systematic review of randomized controlled trials Prostaglandins Other Lipid Mediat. 2025 176 106938 10.1016/j.prostaglandins.2024.106938 39667430 · DOI
  19. [21]Bilezikian J.P. Vitamin D: Dosing, levels, form, and route of administration: Does one approach fit all? Rev. Endocr. Metab. Disord. 2021 22 1201 1218 10.1007/s11154-021-09693-7 34940947 PMC8696970 · DOI
  20. [22]Giustina A. Vitamin D and malabsorptive gastrointestinal conditions: A bidirectional relationship? Rev. Endocr. Metab. Disord. 2023 24 121 138 10.1007/s11154-023-09792-7 36813995 PMC9946876 · DOI
  21. [23]Heikkilä K. Pearce J. Mäki M. Kaukinen K. Celiac disease and bone fractures: A systematic review and meta-analysis J. Clin. Endocrinol. Metab. 2015 100 25 34 10.1210/jc.2014-1858 25279497 · DOI
  22. [24]Trasciatti S. Effect of oral cholecalciferol in a murine model of celiac disease: A dose ranging study J. Steroid Biochem. Mol. Biol. 2022 220 106083 10.1016/j.jsbmb.2022.106083 35257869 · DOI
  23. [25]Szafors P. Che H. Barnetche T. Morel J. Gaujoux-Viala C. Combe B. Lukas C. Risk of fracture and low bone mineral density in adults with inflammatory bowel diseases. A systematic literature review with meta-analysis Osteoporos. Int. 2018 29 2389 2397 10.1007/s00198-018-4586-6 29909470 · DOI
  24. [26]Pludowski P. Takacs I. Boyanov M. Belaya Z. Diaconu C.C. Mokhort T. Zherdova N. Rasa I. Payer J. Pilz S. Clinical Practice in the Prevention, Diagnosis and Treatment of Vitamin D Deficiency: A Central and Eastern European Expert Consensus Statement Nutrients 2022 14 1483 10.3390/nu14071483 35406098 PMC9002638 · DOI
  25. [27]Pludowski P. Supplementing Vitamin D in Different Patient Groups to Reduce Deficiency Nutrients 2023 15 3725 10.3390/nu15173725 37686757 PMC10489803 · DOI
  26. [28]Giustina A. Vitamin D status and supplementation before and after Bariatric Surgery: Recommendations based on a systematic review and meta-analysis Rev. Endocr. Metab. Disord. 2023 24 1011 1029 10.1007/s11154-023-09831-3 37665480 PMC10698146 · DOI
  27. [29]Cantorna M.T. Snyder L. Lin Y.-D. Yang L. Vitamin D and 1,25(OH)2D Regulation of T cells Nutrients 2015 7 3011 3021 10.3390/nu7043011 25912039 PMC4425186 · DOI
  28. [30]Vernia F. Valvano M. Longo S. Cesaro N. Viscido A. Latella G. Vitamin D in Inflammatory Bowel Diseases. Mechanisms of Action and Therapeutic Implications Nutrients 2022 14 269 10.3390/nu14020269 35057450 PMC8779654 · DOI
  29. [31]Wu Z. Liu D. Deng F. The Role of Vitamin D in Immune System and Inflammatory Bowel Disease J. Inflamm. Res. 2022 15 3167 3185 10.2147/JIR.S363840 35662873 PMC9160606 · DOI
  30. [32]Arteh J. Narra S. Nair S. Prevalence of Vitamin D Deficiency in Chronic Liver Disease Dig. Dis. Sci. 2010 55 2624 2628 10.1007/s10620-009-1069-9 19960254 · DOI
  31. [33]Lim L.Y. Chalasani N. Vitamin D Deficiency in Patients with Chronic Liver Disease and Cirrhosis Curr. Gastroenterol. Rep. 2012 14 67 73 10.1007/s11894-011-0231-7 22113744 · DOI
  32. [34]Targher G. Bertolini L. Scala L. Cigolini M. Zenari L. Falezza G. Arcaro G. Associations between serum 25-hydroxyvitamin D3 concentrations and liver histology in patients with non-alcoholic fatty liver disease Nutr. Metab. Cardiovasc. Dis. 2006 17 517 524 10.1016/j.numecd.2006.04.002 16928437 · DOI
  33. [35]Konstantakis C. Tselekouni P. Kalafateli M. Triantos C. Vitamin D deficiency in patients with liver cirrhosis Ann. Gastroenterol. 2016 29 297 306 10.20524/aog.2016.0037 27366029 PMC4923814 · DOI
  34. [36]Mounach A. Ouzzif Z. Wariaghli G. Achemlal L. Benbaghdadi I. Aouragh A. Bezza A. Maghraoui A.E. Primary biliary cirrhosis and osteoporosis: A case-control study J. Bone Miner. Metab. 2008 26 379 384 10.1007/s00774-007-0833-1 18600405 · DOI
  35. [37]Compston J.E. Hepatic osteodystrophy: Vitamin D metabolism in patients with liver disease Gut 1986 27 1073 1090 10.1136/gut.27.9.1073 3530896 PMC1433796 · DOI
  36. [38]Bertoldo F. Cianferotti L. Monaco M.D. Falchetti A. Fassio A. Gatti D. Gennari L. Giannini S. Girasole G. Gonnelli S. Definition, Assessment, and Management of Vitamin D Inadequacy: Suggestions, Recommendations, and Warnings from the Italian Society for Osteoporosis, Mineral Metabolism and Bone Diseases (SIOMMMS) Nutrients 2022 14 4148 10.3390/nu14194148 36235800 PMC9573415 · DOI
  37. [39]Cholongitas E. Theocharidou E. Goulis J. Tsochatzis E. Akriviadis E. Burroughs A.K. Review article: The extra-skeletal effects of vitamin D in chronic hepatitis C infection Aliment. Pharmacol. Ther. 2012 35 634 646 10.1111/j.1365-2036.2012.05000.x 22316435 · DOI
  38. [40]Bitetto D. Fabris C. Falleti E. Fornasiere E. Fumolo E. Fontanini E. Cussigh A. Occhino G. Baccarani U. Pirisi M. Vitamin D and the risk of acute allograft rejection following human liver transplantation Liver Int. 2009 30 417 444 10.1111/j.1478-3231.2009.02154.x 19849776 · DOI
  39. [41]Jean G. Souberbielle J.C. Chazot C. Vitamin D in Chronic Kidney Disease and Dialysis Patients Nutrients 2017 9 328 10.3390/nu9040328 28346348 PMC5409667 · DOI
  40. [42]Vervloet M.G. Vitamin D supplementation in people with chronic kidney disease Kidney Int. 2023 104 698 706 10.1016/j.kint.2023.07.010 37541585 · DOI
  41. [43]Cardoso M.P. Native vitamin D in pre-dialysis chronic kidney disease Nefrol. (Engl. Ed.) 2019 39 18 28 10.1016/j.nefro.2018.07.004 30274806 · DOI
  42. [44]Kaur J. Kamboj K. Yadav A.K. Kaur P. Kumar V. Jha V. Cholecalciferol supplementation and angiogenic markers in chronic kidney disease PLoS ONE 2022 17 e0268946 10.1371/journal.pone.0268946 35657784 PMC9165782 · DOI
  43. [45]Zelnick L.R. de Boer I.H. Kestenbaum B.R. Chonchol M. Kendrick J. Comparative Effects of Cholecalciferol and Calcitriol on Circulating Markers of CKD Mineral Bone Disorder Clin. J. Am. Soc. Nephrol. 2018 13 927 928 10.2215/CJN.00480118 29514798 PMC5989680 · DOI
  44. [46]Iyengar A. Kamath N. Reddy H.V. Sharma J. Singhal J. Uthup S. Ekambaram S. Selvam S. Rahn A. Fischer D.-C. Determining the optimal cholecalciferol dosing regimen in children with CKD: A randomized controlled trial Nephrol. Dial. Transpl. 2022 37 326 334 10.1093/ndt/gfaa369 33367869 · DOI
  45. [47]Franchi M. Paricalcitol and Extended-Release Calcifediol for Treatment of Secondary Hyperparathyroidism in Non-Dialysis Chronic Kidney Disease: Results From a Network Meta-Analysis J. Clin. Endocrinol. Metab. 2023 108 e1424 e1432 10.1210/clinem/dgad289 37235771 PMC10583991 · DOI
  46. [48]Zand L. Kumar R. The Use of Vitamin D Metabolites and Analogs in the Treatment of Chronic Kidney Disease Endocrinol. Metab. Clin. N. Am. 2018 46 983 1007 10.1016/j.ecl.2017.07.008 29080646 PMC5977979 · DOI
  47. [49]Rothen J.-P. Renal insufficiency and magnesium deficiency correlate with a decreased formation of biologically active cholecalciferol: A retrospective observational study Int. J. Clin. Pharm. 2023 45 240 244 10.1007/s11096-022-01485-6 36334229 · DOI
  48. [50]Mahon P. Harvey N. Crozier S. The SWS Study Group, and Keith Godfrey Low maternal vitamin D status and fetal bone development: Cohort study J. Bone Miner. Res. 2010 25 14 19 10.1359/jbmr.090701 19580464 PMC4768344 · DOI
  49. [51]Tamblyn J.A. Hewison M. Wagner C.L. Bulmer J.N. Kilby M.D. Immunological role of vitamin D at the maternal–fetal interface J. Endocrinol. 2015 224 107 121 10.1530/JOE-14-0642 25663707 · DOI
  50. [52]Rostami M. Tehrani F.R. Simbar M. Yarandi R.B. Minooee S. Hollis B.W. Hosseinpanah F. Effectiveness of Prenatal Vitamin D Deficiency Screening and Treatment Program: A Stratified Randomized Field Trial J. Clin. Endocrinol. Metab. 2018 8 2936 2948 10.1210/jc.2018-00109 29788364 · DOI
  51. [53]Lin C. Relationship between vitamin D deficiency and gestational diabetes: A narrative review Front. Endocrinol. 2024 15 1504930 10.3389/fendo.2024.1504930 39749014 PMC11693588 · DOI
  52. [54]Zhao R. Effect of maternal vitamin D status on risk of adverse birth outcomes: A systematic review and dose–response meta-analysis of observational studies Eur. J. Nutr. 2022 61 2881 2907 10.1007/s00394-022-02866-3 35316377 · DOI
  53. [55]Durá-Travé T. Gallinas-Victoriano F. Pregnancy, Breastfeeding, and Vitamin D Int. J. Mol. Sci. 2023 24 11881 10.3390/ijms241511881 37569256 PMC10418507 · DOI
  54. [56]Holick M.F. Binkley N.C. Bischoff-Ferrari H.A. Gordon C.M. Hanley D.A. Heaney R.P. Murad M.H. Weaver C.M. Evaluation, Treatment, and Prevention of Vitamin D Deficiency: An Endocrine Society Clinical Practice Guideline J. Clin. Endocrinol. Metab. 2011 96 1911 1930 10.1210/jc.2011-0385 21646368 · DOI
  55. [57]Demay M.B. Vitamin D for the Prevention of Disease: An Endocrine Society Clinical Practice Guideline J. Clin. Endocrinol. Metab. 2024 109 1907 1947 10.1210/clinem/dgae290 38828931 · DOI · Paper page
  56. [58]Ross A. Manson J. Aloja J. Clinton S. The 2011 report on dietary reference intakes for calcium and vitamin D from the Institute of Medicine: What clinicians need to know Clin. Endocrinol. Metab. 2011 96 53 58 10.1210/jc.2010-2704 21118827 PMC3046611 · DOI
  57. [59]Perez-Lopez F.R. Pilz S. Chedraui P. Vitamin D supplementation during pregnancy: An overview Curr. Opin. Obstet. Gynecol. 2020 32 316 321 10.1097/GCO.0000000000000641 32487800 · DOI
  58. [60]Andersen L.B. Jørgensen J.S. Jensen T.K. Dalga C. Barington T. Nielsen J. Beck-Nielsen S.S. Husby S. Abrahamsen B. Lamont R.F. Vitamin D insufficiency is associated with increased risk of first-trimester miscarriage in the Odense Child Cohort1–2 Am. J. Clin. Nutr. 2015 102 633 638 10.3945/ajcn.114.103655 26178723 · DOI
  59. [61]Shah V.P. A Systematic Review Supporting the Endocrine Society Clinical Practice Guidelines on Vitamin D J. Clin. Endocrinol. Metab. 2024 109 1961 1974 10.1210/clinem/dgae312 38828942 · DOI
  60. [62]World Health Organization WHO Antenatal Care Recommendations for A Positive Pregnancy Experience: Nutritional Interventions Update: Vitamin D Supplements During Pregnancy WHO Geneva, Switzerland 2020 32783436
  61. [63]ACOG Committee Opinion No. 495: Vitamin D: Screening and Supplementation During Pregnancy Obstet. Gynecol. 2011 118 197 198 10.1097/AOG.0b013e318227f06b 21691184 · DOI
  62. [64]FIGO Working Group Good clinical practice advice: Micronutrients in the periconceptional period and pregnancy Int. J. Gynaecol. Obstet. 2019 144 317 321 10.1002/ijgo.12739 30710361 · DOI
  63. [65]Roth D.E. Morris S.K. Zlotkin S. Mahmud A.A. Vitamin D supplementation in pregnancy and lactation to promote infant growth N. Engl. J. Med. 2018 9 535 546 10.1056/NEJMoa1800927 30089075 PMC6004541 · DOI
  64. [66]Dawodu A. Salameh K.M. Al-Janahi N.S. Bener A. Elkum N. The Effect of High-Dose Postpartum Maternal Vitamin D Supplementation Alone Compared with Maternal Plus Infant Vitamin D Supplementation in Breastfeeding Infants in a High-Risk Population. A Randomized Controlled Trial Nutrients 2019 17 1632 10.3390/nu11071632 31319554 PMC6682993 · DOI

Cited by

Sorted by citations

Authors
Bendotti, G., Biamonte, E., Leporati, P., Goglia, U., Ruggeri, R. M., & Gallo, M.
Affiliations
  • Azienda Ospedaliera Nazionale SS. Antonio e Biagio e Cesare Arrigo (IT)
  • Azienda Sanitaria Ospedaliera S.Croce e Carle Cuneo (IT)
  • University of Messina (IT)
Corresponding author
Bendotti, Giulia
ORCID
Venue
Nutrients
Publisher
MDPI AG
Published
2025-02-24
Volume
17
Issue
5
Pages
783
ISSN
2072-6643 (ISSN-L)
DOI
10.3390/nu17050783
PMC
PMC11901608
OpenAlex
W4407909668
Cited by
19
References
2
Citations by year
2026: 10 · 2025: 9
FWCI
2.97
Type
journal article
Language
en
Open access
Licence
Locations
  • Nutrients (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
Funders
S.I.S.A (Società Italiana di Scienza dell’Alimentazione)
Topics
  • Health Sciences › Medicine › Pathology and Forensic Medicine › Vitamin D Research Studies
  • Health Sciences › Medicine › Public Health, Environmental and Occupational Health › Nutrition and Health Studies
  • Health Sciences › Nursing › Nutrition and Dietetics › Vitamin K Research Studies
Keywords
vitamin D supplementation, vitamin D deficiency, bone health, fracture prevention, diabetes mellitus, autoimmune disease, cardiovascular disease, renal function, pregnancy, body weight, absorption capacity, metabolic rate
MeSH terms
Female, Humans, Pregnancy, Vitamin D, Vitamin D Deficiency, Dietary Supplements

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review