{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,6]],"date-time":"2026-07-06T04:17:03Z","timestamp":1783311423605,"version":"3.54.6"},"reference-count":53,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2026,7,2]],"date-time":"2026-07-02T00:00:00Z","timestamp":1782950400000},"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: Serum 25-hydroxyvitamin D [25(OH)D] is a clinically used biomarker of vitamin D nutritional status, although it is also influenced by sunlight exposure, supplementation, season, and other host factors. Short-term functional status after extracorporeal shock wave therapy (ESWT) for lateral epicondylitis varies. We evaluated whether serum 25(OH)D level and status were associated with 12-week functional outcomes among ESWT-treated patients. Methods: This single-center retrospective cohort included 62 adults with lateral epicondylitis who received outpatient ESWT and had baseline and 12-week assessments. Baseline variables included grip strength ratio, Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) score, serum 25(OH)D measured using the Architect 25-OH D vitamin kit, common extensor tendon (CET) thickness, age, sex, and body mass index. Multivariable linear regression was used in an analysis-of-covariance framework. Serum 25(OH)D was assessed continuously and as &lt;20 versus \u226520 ng\/mL in exploratory threshold analysis. Results: Serum 25(OH)D was 21.0 \u00b1 8.4 ng\/mL; 30 patients (48.4%) had &lt;20 ng\/mL, 22 (35.5%) had 20\u201329.9 ng\/mL, and 10 (16.1%) had \u226530 ng\/mL. QuickDASH decreased from 42.0 \u00b1 17.4 to 27.0 \u00b1 13.7, and grip strength ratio increased from 0.58 \u00b1 0.14 to 0.76 \u00b1 0.14. Higher serum 25(OH)D was associated with lower 12-week QuickDASH after adjustment (\u03b2 per 10 ng\/mL = \u22124.04, 95% CI \u22127.17 to \u22120.91; p = 0.012). Additionally, 25(OH)D &lt;20 ng\/mL was associated with higher 12-week QuickDASH (\u03b2 = 6.43, 95% CI 1.17 to 11.69; p = 0.017). Serum 25(OH)D was not clearly associated with 12-week grip strength ratio. Conclusions: Lower serum 25(OH)D, interpreted as a vitamin D nutritional-status marker rather than as a nutrition-specific causal exposure, was associated with worse 12-week patient-reported function, but not grip strength ratio. The &lt;20 ng\/mL threshold analysis was exploratory and was not powered for subgroup inference. These findings should be interpreted as observational and hypothesis-generating.<\/jats:p>","DOI":"10.3390\/nu18132152","type":"journal-article","created":{"date-parts":[[2026,7,2]],"date-time":"2026-07-02T15:52:24Z","timestamp":1783007544000},"page":"2152","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Serum 25-Hydroxyvitamin D Status and 12-Week Functional Outcomes After Extracorporeal Shock Wave Therapy for Lateral Epicondylitis: A Retrospective Cohort Study"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1926-3228","authenticated-orcid":false,"given":"Ki-Hyeok","family":"Ku","sequence":"first","affiliation":[{"name":"Department of Orthopedic Surgery, Kyung Hee University College of Medicine, Kyung Hee University Hospital at Gangdong, Seoul 05278, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9364-2947","authenticated-orcid":false,"given":"Eo Jin","family":"Park","sequence":"additional","affiliation":[{"name":"Department of Rehabilitation Medicine, Kyung Hee University College of Medicine, Kyung Hee University Hospital at Gangdong, Seoul 05278, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"Cpg1","DOI":"10.2519\/jospt.2022.0302","article-title":"Lateral Elbow Pain and Muscle Function Impairments","volume":"52","author":"Lucado","year":"2022","journal-title":"J. Orthop. Sports Phys. Ther."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1016\/j.berh.2011.01.013","article-title":"Lateral and medial epicondylitis: Role of occupational factors","volume":"25","author":"Shiri","year":"2011","journal-title":"Best. Pract. Res. Clin. Rheumatol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"259","DOI":"10.2106\/00004623-199902000-00014","article-title":"Tendinosis of the elbow (tennis elbow). Clinical features and findings of histological, immunohistochemical, and electron microscopy studies","volume":"81","author":"Kraushaar","year":"1999","journal-title":"J. Bone Jt. Surg. Am."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"851","DOI":"10.1016\/S0278-5919(20)30489-0","article-title":"Elbow tendinosis\/tennis elbow","volume":"11","author":"Nirschl","year":"1992","journal-title":"Clin. Sports Med."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"317","DOI":"10.1053\/apmr.2002.29620","article-title":"Chronic medial and lateral epicondylitis: A comparison of pain, disability, and function","volume":"83","author":"Siira","year":"2002","journal-title":"Arch. Phys. Med. Rehabil."},{"key":"ref_6","first-page":"2053","article-title":"Lateral epicondylitis in general practice: Course and prognostic indicators of outcome","volume":"33","author":"Smidt","year":"2006","journal-title":"J. Rheumatol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1216","DOI":"10.1093\/rheumatology\/keg360","article-title":"Prognostic factors in lateral epicondylitis: A randomized trial with one-year follow-up in 266 new cases treated with minimal occupational intervention or the usual approach in general practice","volume":"42","author":"Haahr","year":"2003","journal-title":"Rheumatology"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"e24","DOI":"10.2106\/JBJS.RVW.24.00059","article-title":"Recalcitrant Lateral Epicondylitis: A Systematic Review on Current Nonoperative and Operative Treatment Modalities","volume":"12","author":"Kim","year":"2024","journal-title":"JBJS Rev."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"e22","DOI":"10.2106\/JBJS.RVW.22.00170","article-title":"Lateral Epicondylitis: Critical Analysis Review of Current Nonoperative Treatments","volume":"11","author":"Marigi","year":"2023","journal-title":"JBJS Rev."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2064781","DOI":"10.1155\/2020\/2064781","article-title":"Efficacy of Extracorporeal Shock Wave Therapy for Lateral Epicondylitis: A Systematic Review and Meta-Analysis","volume":"2020","author":"Yao","year":"2020","journal-title":"Biomed. Res. Int."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1383","DOI":"10.1177\/02692155211006860","article-title":"Clinical effectiveness of shockwave therapy in lateral elbow tendinopathy: Systematic review and meta-analysis","volume":"35","author":"Karanasios","year":"2021","journal-title":"Clin. Rehabil."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"495","DOI":"10.1097\/PHM.0000000000000407","article-title":"Radial Extracorporeal Shock Wave Therapy Is Not More Effective Than Placebo in the Management of Lateral Epicondylitis: A Double-Blind, Randomized, Placebo-Controlled Trial","volume":"95","author":"Capan","year":"2016","journal-title":"Am. J. Phys. Med. Rehabil."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"938","DOI":"10.2519\/jospt.2015.5841","article-title":"Management of Lateral Elbow Tendinopathy: One Size Does Not Fit All","volume":"45","author":"Coombes","year":"2015","journal-title":"J. Orthop. Sports Phys. Ther."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1209","DOI":"10.1177\/0363546509359066","article-title":"Lateral elbow tendinopathy: Correlation of ultrasound findings with pain and functional disability","volume":"38","author":"Clarke","year":"2010","journal-title":"Am. J. Sports Med."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Ikeda, K., Ikumi, A., Onishi, S., Ogawa, T., Kohyama, S., and Yoshii, Y. (2025). Predicting refractoriness in lateral epicondylitis using initial grip strength and quickdash: A retrospective cohort study. BMC Musculoskelet. Disord., 26.","DOI":"10.1186\/s12891-025-08902-7"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"803","DOI":"10.2519\/jospt.2022.11211","article-title":"Low-Load Resistance Training With Blood Flow Restriction Is Effective for Managing Lateral Elbow Tendinopathy: A Randomized, Sham-Controlled Trial","volume":"52","author":"Karanasios","year":"2022","journal-title":"J. Orthop. Sports Phys. Ther."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Gummesson, C., Ward, M.M., and Atroshi, I. (2006). The shortened disabilities of the arm, shoulder and hand questionnaire (QuickDASH): Validity and reliability based on responses within the full-length DASH. BMC Musculoskelet. Disord., 7.","DOI":"10.1186\/1471-2474-7-44"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"2509","DOI":"10.1007\/s11136-013-0362-4","article-title":"Measurement properties of the QuickDASH (disabilities of the arm, shoulder and hand) outcome measure and cross-cultural adaptations of the QuickDASH: A systematic review","volume":"22","author":"Kennedy","year":"2013","journal-title":"Qual. Life Res."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1363","DOI":"10.2214\/AJR.10.5769","article-title":"Utility of sonographic measurement of the common tensor tendon in patients with lateral epicondylitis","volume":"196","author":"Lee","year":"2011","journal-title":"AJR Am. J. Roentgenol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1873","DOI":"10.1177\/0363546520921949","article-title":"Clinical Value of Ultrasonographic Assessment in Lateral Epicondylitis Versus Asymptomatic Healthy Controls","volume":"48","author":"Krogh","year":"2020","journal-title":"Am. J. Sports Med."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"109","DOI":"10.4274\/MMJ.galenos.2024.60308","article-title":"Clinical and Sonographic Evaluation of the Effectiveness of Extracorporeal Shock Wave Therapy in Patients with Lateral Epicondylitis","volume":"39","author":"Murat","year":"2024","journal-title":"Medeni. Med. J."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"76","DOI":"10.3906\/sag-2001-79","article-title":"Comparison of the clinical and sonographic effects of ultrasound therapy, extracorporeal shock wave therapy, and Kinesio taping in lateral epicondylitis","volume":"51","author":"Koparal","year":"2021","journal-title":"Turk. J. Med. Sci."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"414","DOI":"10.52312\/jdrs.2022.686","article-title":"Evaluation of the relationship between lateral epicondylitis and vitamin D","volume":"33","author":"Yaka","year":"2022","journal-title":"Jt. Dis. Relat. Surg."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1911","DOI":"10.1210\/jc.2011-0385","article-title":"Evaluation, treatment, and prevention of vitamin D deficiency: An Endocrine Society clinical practice guideline","volume":"96","author":"Holick","year":"2011","journal-title":"J. Clin. Endocrinol. Metab."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1515\/jbcpp-2024-0061","article-title":"Exploring the impact of vitamin D on tendon health: A comprehensive review","volume":"35","author":"Tarantino","year":"2024","journal-title":"J. Basic. Clin. Physiol. Pharmacol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"203","DOI":"10.1016\/j.jor.2019.08.005","article-title":"Tennis elbow: A clinical review article","volume":"17","author":"Cutts","year":"2020","journal-title":"J. Orthop."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"707","DOI":"10.31128\/AJGP-07-20-5519","article-title":"Lateral epicondylitis: Current concepts","volume":"49","author":"Johns","year":"2020","journal-title":"Aust. J. Gen. Pract."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1","DOI":"10.4055\/cios21090","article-title":"Grip Strength Measurement for Outcome Assessment in Common Hand Surgeries","volume":"14","author":"Lee","year":"2022","journal-title":"Clin. Orthop. Surg."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"85","DOI":"10.11005\/jbm.2020.27.2.85","article-title":"Measurement and Interpretation of Handgrip Strength for Research on Sarcopenia and Osteoporosis","volume":"27","author":"Lee","year":"2020","journal-title":"J. Bone Metab."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"423","DOI":"10.1093\/ageing\/afr051","article-title":"A review of the measurement of grip strength in clinical and epidemiological studies: Towards a standardised approach","volume":"40","author":"Roberts","year":"2011","journal-title":"Age Ageing"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Beumer, A., and Lindau, T.R. (2014). Grip strength ratio: A grip strength measurement that correlates well with DASH score in different hand\/wrist conditions. BMC Musculoskelet. Disord., 15.","DOI":"10.1186\/1471-2474-15-336"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"427","DOI":"10.1055\/s-0043-1772254","article-title":"Patient-Reported Outcomes Can Serve as a Functional Substitute for Grip Strength","volume":"13","author":"Cantu","year":"2024","journal-title":"J. Wrist Surg."},{"key":"ref_33","first-page":"1038","article-title":"Development of the QuickDASH: Comparison of three item-reduction approaches","volume":"87","author":"Beaton","year":"2005","journal-title":"J. Bone Jt. Surg. Am."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1592","DOI":"10.1016\/j.ultrasmedbio.2015.01.018","article-title":"Reliability and agreement of ultrasonographic thickness measurements of the common lateral extensors of the elbow","volume":"41","author":"Teggeler","year":"2015","journal-title":"Ultrasound Med. Biol."},{"key":"ref_35","first-page":"1297","article-title":"Extracorporeal shock wave therapy without local anesthesia for chronic lateral epicondylitis","volume":"87","author":"Pettrone","year":"2005","journal-title":"J. Bone Jt. Surg. Am."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Buchbinder, R., Green, S., White, M., Barnsley, L., Smidt, N., and Assendelft, W.J. (2002). Shock wave therapy for lateral elbow pain. Cochrane Database Syst. Rev.","DOI":"10.1002\/14651858.CD003524"},{"key":"ref_37","first-page":"17","article-title":"Radial shock wave therapy for lateral epicondylitis: A prospective randomised controlled single-blind study","volume":"41","author":"Spacca","year":"2005","journal-title":"Eura Medicophys"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1660","DOI":"10.1177\/0363546503262806","article-title":"Effectiveness of extracorporeal shock wave therapy in the treatment of previously untreated lateral epicondylitis: A randomized controlled trial","volume":"32","author":"Chung","year":"2004","journal-title":"Am. J. Sports Med."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Karjalainen, T., L\u00e4hdeoja, T., Salmela, M., Ardern, C.L., Juurakko, J., J\u00e4rvinen, T.L., and Taimela, S. (2023). Minimal important difference, patient acceptable symptom state and longitudinal validity of oxford elbow score and the quickDASH in patients with tennis elbow. BMC Med. Res. Methodol., 23.","DOI":"10.1186\/s12874-023-01934-4"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"pzae033","DOI":"10.1093\/ptj\/pzae033","article-title":"Minimal Clinically Important Difference of the Disabilities of the Arm, Shoulder and Hand (DASH) and the Shortened Version of the DASH (QuickDASH) in People With Musculoskeletal Disorders: A Systematic Review and Meta-Analysis","volume":"104","author":"Galardini","year":"2024","journal-title":"Phys. Ther."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1145","DOI":"10.1053\/apmr.2002.33728","article-title":"Interobserver reproducibility of the assessment of severity of complaints, grip strength, and pressure pain threshold in patients with lateral epicondylitis","volume":"83","author":"Smidt","year":"2002","journal-title":"Arch. Phys. Med. Rehabil."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"602","DOI":"10.1002\/(SICI)1097-0274(199606)29:6<602::AID-AJIM4>3.0.CO;2-L","article-title":"Development of an upper extremity outcome measure: The DASH (disabilities of the arm, shoulder and hand)","volume":"29","author":"Hudak","year":"1996","journal-title":"Am. J. Ind. Med."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Dixon, D., Johnston, M., McQueen, M., and Court-Brown, C. (2008). The Disabilities of the Arm, Shoulder and Hand Questionnaire (DASH) can measure the impairment, activity limitations and participation restriction constructs from the International Classification of Functioning, Disability and Health (ICF). BMC Musculoskelet. Disord., 9.","DOI":"10.1186\/1471-2474-9-114"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"250.e1","DOI":"10.1016\/j.jhsa.2018.06.013","article-title":"The Prognostic Value of Pain Sensitization in Patients with Lateral Epicondylitis","volume":"44","author":"Roh","year":"2019","journal-title":"J. Hand Surg. Am."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"777","DOI":"10.2214\/ajr.176.3.1760777","article-title":"Sonographic examination of lateral epicondylitis","volume":"176","author":"Connell","year":"2001","journal-title":"AJR Am. J. Roentgenol."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"76","DOI":"10.2106\/JBJS.L.00064","article-title":"Contribution of kinesophobia and catastrophic thinking to upper-extremity-specific disability","volume":"95","author":"Vranceanu","year":"2013","journal-title":"J. Bone Jt. Surg. Am."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"864","DOI":"10.2519\/jospt.2015.5895","article-title":"Evidence of Nervous System Sensitization in Commonly Presenting and Persistent Painful Tendinopathies: A Systematic Review","volume":"45","author":"Plinsinga","year":"2015","journal-title":"J. Orthop. Sports Phys. Ther."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"482","DOI":"10.1097\/AJP.0b013e31805f70fa","article-title":"Pain, functional disability, and psychologic status in tennis elbow","volume":"23","author":"Alizadehkhaiyat","year":"2007","journal-title":"Clin. J. Pain."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"1043","DOI":"10.1007\/s11136-009-9529-4","article-title":"How sharp is the short QuickDASH? A refined content and validity analysis of the short form of the disabilities of the shoulder, arm and hand questionnaire in the strata of symptoms and function and specific joint conditions","volume":"18","author":"Angst","year":"2009","journal-title":"Qual. Life Res."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"230","DOI":"10.1148\/radiol.2371040784","article-title":"Lateral epicondylitis of the elbow: US findings","volume":"237","author":"Levin","year":"2005","journal-title":"Radiology"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"407","DOI":"10.1016\/j.mam.2008.07.002","article-title":"Vitamin D and skeletal muscle tissue and function","volume":"29","author":"Ceglia","year":"2008","journal-title":"Mol. Asp. Med."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1016\/j.maturitas.2016.11.017","article-title":"Serum vitamin d and sex hormones levels in men and women: The multi-ethnic study of atherosclerosis (mesa)","volume":"96","author":"Zhao","year":"2017","journal-title":"Maturitas"},{"key":"ref_53","doi-asserted-by":"crossref","unstructured":"Muscogiuri, G., Barrea, L., Somma, C.D., Laudisio, D., Salzano, C., Pugliese, G., de Alteriis, G., Colao, A., and Savastano, S. (2019). Sex differences of vitamin d status across bmi classes: An observational prospective cohort study. Nutrients, 11.","DOI":"10.3390\/nu11123034"}],"container-title":["Nutrients"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-6643\/18\/13\/2152\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,6]],"date-time":"2026-07-06T04:12:17Z","timestamp":1783311137000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-6643\/18\/13\/2152"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,2]]},"references-count":53,"journal-issue":{"issue":"13","published-online":{"date-parts":[[2026,7]]}},"alternative-id":["nu18132152"],"URL":"https:\/\/doi.org\/10.3390\/nu18132152","relation":{},"ISSN":["2072-6643"],"issn-type":[{"value":"2072-6643","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,2]]}}}