{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,23]],"date-time":"2026-06-23T16:58:13Z","timestamp":1782233893106,"version":"3.54.5"},"reference-count":63,"publisher":"MDPI AG","issue":"20","license":[{"start":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T00:00:00Z","timestamp":1760140800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan","award":["AP19677442"],"award-info":[{"award-number":["AP19677442"]}]},{"name":"the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan","award":["AP19680003"],"award-info":[{"award-number":["AP19680003"]}]},{"name":"the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan","award":["BR27199879"],"award-info":[{"award-number":["BR27199879"]}]},{"name":"the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan","award":["BR24993023"],"award-info":[{"award-number":["BR24993023"]}]},{"name":"the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan","award":["BR24992841"],"award-info":[{"award-number":["BR24992841"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nutrients"],"abstract":"<jats:p>Background\/Objectives: We aimed to investigate the association between VDR gene variants and vitamin D levels in elite male power athletes of Kazakhstan. Methods: We recruited 92 elite male power athletes of Kazakhstan. Concentrations of serum 25(OH)D were measured with the Access 25(OH) Vitamin D Total Assay on the Unicel Dxl 800 Access Immunoassay System. Gene polymorphisms were determined by a real-time polymerase chain reaction (RT-PCR) allelic discrimination assay using TaqMan\u2122 probes. Results: Vitamin D insufficiency was registered in 63% of athletes. Age (\u03c72 = 6.83, p &lt; 0.01), BMI (\u03c72 = 6.83, p &lt; 0.01), and sport experience (\u03c72 = 4.44, p &lt; 0.04) showed a statistically significant association with vitamin D insufficiency and deficiency (age, \u03c72 = 7.93, p &lt; 0.01; BMI, \u03c72 = 5.11, p &lt; 0.03; sport experience, \u03c72 = 6.19, p = 0.01). The A\/A genotype of the VDR FokI polymorphism (rs2228570) showed a strong correlation with vitamin D insufficiency (G\/G-G\/A vs. A\/A, OR = 9.25, 95% CI = 2.01\u201342.51, p &lt; 0.01) but not deficiency. Conclusions: Our study reveals a significant prevalence of vitamin D insufficiency and deficiency among elite male power athletes of Kazakhstan. Age, BMI, and sport experience are essential factors in developing personalized strategies to address vitamin D insufficiency. The A\/A genotype of the VDR FokI polymorphism can be used as a potential biomarker for vitamin D inadequacy in elite male power athletes of Kazakhstan.<\/jats:p>","DOI":"10.3390\/nu17203195","type":"journal-article","created":{"date-parts":[[2025,10,14]],"date-time":"2025-10-14T07:51:28Z","timestamp":1760428288000},"page":"3195","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["FokI Polymorphism of the VDR Gene Is Associated with Vitamin D Insufficiency in Elite Male Power Athletes of Kazakhstan"],"prefix":"10.3390","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1551-3637","authenticated-orcid":false,"given":"Aidana","family":"Gabdulkayum","sequence":"first","affiliation":[{"name":"Laboratory of Genomic and Personalized Medicine, Center for Life Sciences, National Laboratory Astana, Nazarbayev University, Astana 010000, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Saya","family":"Amangeldikyzy","sequence":"additional","affiliation":[{"name":"The National Center for Children\u2019s Rehabilitation, Astana 010000, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Adil","family":"Yerezhepov","sequence":"additional","affiliation":[{"name":"Department of Biotechnology, Al-Farabi Kazakh National University, Almaty 050040, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sayipzhamal","family":"Khassanova","sequence":"additional","affiliation":[{"name":"The National Center for Sports Medicine and Rehabilitation, Almaty 020000, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3342-2424","authenticated-orcid":false,"given":"Kenes R.","family":"Akilzhanov","sequence":"additional","affiliation":[{"name":"Department of Medicine, Semey Medical University, Pavlodar Branch, Pavlodar 140000, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ulan","family":"Kozhamkulov","sequence":"additional","affiliation":[{"name":"Laboratory of Genomic and Personalized Medicine, Center for Life Sciences, National Laboratory Astana, Nazarbayev University, Astana 010000, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8245-2400","authenticated-orcid":false,"given":"Saule","family":"Rakhimova","sequence":"additional","affiliation":[{"name":"Laboratory of Genomic and Personalized Medicine, Center for Life Sciences, National Laboratory Astana, Nazarbayev University, Astana 010000, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8511-8064","authenticated-orcid":false,"given":"Ulykbek","family":"Kairov","sequence":"additional","affiliation":[{"name":"Laboratory of Bioinformatics and Systems Biology, Center for Life Sciences, National Laboratory Astana, Nazarbayev University, Astana 010000, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6161-8355","authenticated-orcid":false,"given":"Ainur","family":"Akilzhanova","sequence":"additional","affiliation":[{"name":"Laboratory of Genomic and Personalized Medicine, Center for Life Sciences, National Laboratory Astana, Nazarbayev University, Astana 010000, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4161-1348","authenticated-orcid":false,"given":"Dauren","family":"Yerezhepov","sequence":"additional","affiliation":[{"name":"Laboratory of Genomic and Personalized Medicine, Center for Life Sciences, National Laboratory Astana, Nazarbayev University, Astana 010000, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,10,11]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1299","DOI":"10.1093\/jn\/134.6.1299","article-title":"The Discovery of Vitamin D: The Contribution of Adolf Windaus","volume":"134","author":"Wolf","year":"2004","journal-title":"J. Nutr."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"319","DOI":"10.1016\/j.chembiol.2013.12.016","article-title":"Vitamin D Metabolism, Mechanism of Action, and Clinical Applications","volume":"21","author":"Bikle","year":"2014","journal-title":"Chem. Biol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1070808","DOI":"10.3389\/fnut.2023.1070808","article-title":"Global and Regional Prevalence of Vitamin D Deficiency in Population-Based Studies from 2000 to 2022: A Pooled Analysis of 7.9 Million Participants","volume":"10","author":"Cui","year":"2023","journal-title":"Front. Nutr."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1109","DOI":"10.1210\/er.2018-00126","article-title":"Skeletal and Extraskeletal Actions of Vitamin D: Current Evidence and Outstanding Questions","volume":"40","author":"Bouillon","year":"2019","journal-title":"Endocr. Rev."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Voltan, G., Cannito, M., Ferrarese, M., Ceccato, F., and Camozzi, V. (2023). Vitamin D: An Overview of Gene Regulation, Ranging from Metabolism to Genomic Effects. Genes, 14.","DOI":"10.3390\/genes14091691"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"3857","DOI":"10.1007\/s00394-022-02967-z","article-title":"Prevalence and Novel Risk Factors for Vitamin D Insufficiency in Elite Athletes: Systematic Review and Meta-Analysis","volume":"61","author":"Harju","year":"2022","journal-title":"Eur. J. Nutr."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Flore, L., Robledo, R., Dettori, L., Scorcu, M., Francalacci, P., Tocco, F., Massidda, M., and Cal\u00f2, C.M. (2024). Association of VDR Polymorphisms with Muscle Mass Development in Elite Young Soccer Players: A Pilot Study. Sports, 12.","DOI":"10.20944\/preprints202407.1560.v1"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"496","DOI":"10.1177\/1941738112461621","article-title":"Sports Health Benefits of Vitamin D","volume":"4","author":"Shuler","year":"2022","journal-title":"Sports Health"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Miraj, S.S., Thunga, G., Kunhikatta, V., Rao, M., and Nair, S. (2018). Benefits of Vitamin D in Sport Nutrition. Nutrition and Enhancing Sports Performance: Muscle Building, Endurance, and Strength, Elsevier.","DOI":"10.1016\/B978-0-12-813922-6.00042-4"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"291","DOI":"10.1016\/S0140-6736(03)15388-3","article-title":"Synthesis of Vitamin D in Skin after Burns","volume":"363","author":"Klein","year":"2004","journal-title":"Lancet"},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Pop, T.L., S\u00eerbe, C., Ben\u0163a, G., Mititelu, A., and Grama, A. (2022). The Role of Vitamin D and Vitamin D Binding Protein in Chronic Liver Diseases. Int. J. Mol. Sci., 23.","DOI":"10.3390\/ijms231810705"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1165","DOI":"10.1210\/mend.11.8.9951","article-title":"Structural Organization of the Human Vitamin D Receptor Chromosomal Gene and Its Promoter","volume":"11","author":"Miyamoto","year":"1997","journal-title":"Mol. Endocrinol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"438","DOI":"10.1016\/j.jsbmb.2010.03.052","article-title":"Association between Polymorphic Variation in VDR and RXRA and Circulating Levels of Vitamin D Metabolites","volume":"121","author":"Hibler","year":"2010","journal-title":"J. Steroid Biochem. Mol. Biol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"156958","DOI":"10.1016\/j.cyto.2025.156958","article-title":"FokI Polymorphism of the Vitamin D Receptor Gene: Linking COVID-19 Risk to Genetic Susceptibility in Children","volume":"191","author":"Mohamed","year":"2025","journal-title":"Cytokine"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Gilioli da Costa Nunes, G., Cezar Aquino de Moraes, F., Carvalho de Almeida, A.B., Goes Costa, F., Duarte de Andrade Junior, L.F., Sabino Hupp, M.V., Rotondano Assun\u00e7\u00e3o, R., Rodrigues Fernandes, M., Emanuel Batista dos Santos, S., and Pereira Carneiro dos Santos, N. (2025). Single-Nucleotide Polymorphisms Related to Multiple Myeloma Risk: A Systematic Review and Meta-Analysis. Int. J. Mol. Sci., 26.","DOI":"10.3390\/ijms26073369"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Gonz\u00e1lez Rojo, P., P\u00e9rez Ram\u00edrez, C., G\u00e1lvez Navas, J.M., Pineda Lancheros, L.E., Rojo Tolosa, S., Ramirez Tortosa, M.D.C., and Jim\u00e9nez Morales, A. (2022). Vitamin D-Related Single Nucleotide Polymorphisms as Risk Biomarkers of Cardiovascular Disease. Int. J. Mol. Sci., 23.","DOI":"10.3390\/ijms23158686"},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Yerezhepov, D., Gabdulkayum, A., Akhmetova, A., Kozhamkulov, U.A., Rakhimova, S.E., Kairov, U.Y., Zhunussova, G., Kalendar, R.N., and Akilzhanova, A. (2024). Vitamin D Status, VDR, and TLR Polymorphisms and Pulmonary Tuberculosis Epidemiology in Kazakhstan. Nutrients, 16.","DOI":"10.3390\/nu16040558"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Bulgay, C., Bayraktar, I., Kazan, H.H., Y\u0131ld\u0131r\u0131m, D.S., Zorba, E., Akman, O., Ergun, M.A., Cerit, M., Ulucan, K., and Eken, \u00d6. (2023). Evaluation of the Association of VDR rs2228570 Polymorphism with Elite Track and Field Athletes\u2019 Competitive Performance. Healthcare, 11.","DOI":"10.3390\/healthcare11050681"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1595","DOI":"10.1007\/s00421-016-3411-1","article-title":"Genetic Variation and Exercise-Induced Muscle Damage: Implications for Athletic Performance, Injury, and Ageing","volume":"116","author":"Baumert","year":"2016","journal-title":"Eur. J. Appl. Physiol."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Marques, I.S., Tavares, V., Vieira Neto, B., Lopes, L.R., Goes, R.A., Guimar\u00e3es, J.A.M., Perini, J.A., and Medeiros, R. (2024). Genetic Variations in Susceptibility to Traumatic Muscle Injuries and Muscle Pain among Brazilian High-Performance Athletes. Int. J. Mol. Sci., 25.","DOI":"10.3390\/ijms25063300"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"564","DOI":"10.1016\/j.jsams.2017.10.038","article-title":"The Association of Novel Polymorphisms with Stress Fracture Injury in Elite Athletes: Further Insights from the SFEA Cohort","volume":"21","author":"Varley","year":"2018","journal-title":"J. Sci. Med. Sport"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"413","DOI":"10.1016\/S0733-8651(05)70349-0","article-title":"The Power Athlete","volume":"15","author":"Longhurst","year":"1997","journal-title":"Cardiol. Clin."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"de la Puente Yag\u00fce, M., Collado Yurrita, L., Ciudad Caba\u00f1as, M.J., and Cuadrado Cenzual, M.A. (2020). Role of Vitamin D in Athletes and Their Performance: Current Concepts and New Trends. Nutrients, 12.","DOI":"10.3390\/nu12020579"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"486","DOI":"10.1016\/j.clinbiochem.2015.11.022","article-title":"Evaluation of the Analytical Performance of Unicel DXI 800 for Total 25(OH) Vitamin D Measurements","volume":"49","author":"Ozcan","year":"2016","journal-title":"Clin. Biochem."},{"key":"ref_25","first-page":"22","article-title":"Vitamin D Deficiency in Athletes: Laboratory, Clinical, and Field Integration","volume":"29","author":"Ip","year":"2022","journal-title":"Asia-Pac. J. Sports Med. Arthrosc. Rehabil. Technol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1080S","DOI":"10.1093\/ajcn\/87.4.1080S","article-title":"Vitamin D deficiency: A worldwide problem with health consequences","volume":"87","author":"Holick","year":"2008","journal-title":"Am. J. Clin. Nutr."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1016\/S2213-8587(13)70165-7","article-title":"Vitamin D Status and Ill Health: A Systematic Review","volume":"2","author":"Autier","year":"2014","journal-title":"Lancet Diabetes Endocrinol."},{"key":"ref_28","first-page":"e066452","article-title":"Vitamin D and Fish Oil Supplements and Risk of Autoimmune Disease","volume":"376","author":"Costenbader","year":"2022","journal-title":"BMJ"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"269","DOI":"10.26719\/emhj.20.119","article-title":"Effect of Latitude on Seasonal Variations of Vitamin D and Some Cardiometabolic Risk Factors: National Food and Nutrition Surveillance","volume":"27","author":"Nikooyeh","year":"2021","journal-title":"East Mediterr. Health J."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"105565","DOI":"10.1016\/j.jsbmb.2019.105565","article-title":"Vitamin D Deficiency in Kazakhstan: Cross-Sectional Study","volume":"199","author":"Gromova","year":"2020","journal-title":"J. Steroid Biochem. Mol. Biol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"151","DOI":"10.1007\/s00223-012-9645-y","article-title":"Vitamin D and Its Role in Skeletal Muscle","volume":"92","author":"Ceglia","year":"2012","journal-title":"Calcif. Tissue Int."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1153","DOI":"10.1210\/jc.2011-2601","article-title":"Guidelines for Preventing and Treating Vitamin D Deficiency and Insufficiency Revisited","volume":"97","author":"Holick","year":"2012","journal-title":"J. Clin. Endocrinol. Metab."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1549","DOI":"10.1007\/s00421-024-05699-6","article-title":"Vitamin D Status and Its Determinants in German Elite Athletes","volume":"125","author":"Hacker","year":"2025","journal-title":"Eur. J. Appl. Physiol."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Bezuglov, E., Tikhonova, A., Zueva, A., Khaitin, V., Wa\u015bkiewicz, Z., Gerasimuk, D., \u017bebrowska, A., Rosemann, T., Nikolaidis, P., and Knechtle, B. (2019). Prevalence and Treatment of Vitamin D Deficiency in Young Male Russian Soccer Players in Winter. Nutrients, 11.","DOI":"10.3390\/nu11102405"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"2325967118774329","DOI":"10.1177\/2325967118774329","article-title":"Vitamin D Insufficiency among Professional Basketball Players: A Relationship to Fracture Risk and Athletic Performance","volume":"6","author":"Grieshober","year":"2018","journal-title":"Orthop. J. Sports Med."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"365","DOI":"10.1007\/s40279-014-0267-6","article-title":"Prevalence of Vitamin D Inadequacy in Athletes: A Systematic-Review and Meta-Analysis","volume":"45","author":"Farrokhyar","year":"2015","journal-title":"Sports Med."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"139","DOI":"10.1016\/j.jsams.2013.03.006","article-title":"Vitamin D Concentration in 342 Professional Football Players and Association with Lower Limb Isokinetic Function","volume":"17","author":"Hamilton","year":"2014","journal-title":"J. Sci. Med. Sport"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"2325967116677512","DOI":"10.1177\/2325967116677512","article-title":"Prevalence of Vitamin D Insufficiency in Professional Hockey Players","volume":"4","author":"Mehran","year":"2016","journal-title":"Orthop. J. Sports Med."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"3436","DOI":"10.1016\/j.clnu.2020.11.019","article-title":"Differences and Determinants of Vitamin D Deficiency among UK Biobank Participants: A Cross-Ethnic and Socioeconomic Study","volume":"40","author":"Sutherland","year":"2021","journal-title":"Clin. Nutr."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"106737","DOI":"10.1016\/j.jsbmb.2025.106737","article-title":"Prevalence and Determinants of Profound Vitamin D Deficiency (25-Hydroxyvitamin D <10 nmol\/L) in the UK Biobank and Potential Implications for Disease Association Studies","volume":"250","author":"Shraim","year":"2025","journal-title":"J. Steroid Biochem. Mol. Biol."},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"B\u00e2rsan, M., Chelaru, V.-F., R\u00e2jnoveanu, A.-G., Popa, \u0218.L., Socaciu, A.I., and B\u0103dulescu, A.V. (2023). Difference in Levels of Vitamin D between Indoor and Outdoor Athletes: A Systematic Review and Meta-Analysis. Int. J. Mol. Sci., 24.","DOI":"10.3390\/ijms24087584"},{"key":"ref_42","first-page":"124","article-title":"High Prevalence of Vitamin D Insufficiency among Elite Spanish Athletes: The Importance of Outdoor Training Adaptation","volume":"30","author":"Dominguez","year":"2014","journal-title":"Nutr. Hosp."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"20","DOI":"10.20463\/pan.2021.0011","article-title":"Vitamin D in Athletes: Focus on Physical Performance and Musculoskeletal Injuries","volume":"25","author":"Yoon","year":"2021","journal-title":"Phys. Act. Nutr."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1856","DOI":"10.3390\/nu5061856","article-title":"Vitamin D and the Athlete: Risks, Recommendations, and Benefits","volume":"5","author":"Ogan","year":"2013","journal-title":"Nutrients"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"433","DOI":"10.1007\/s00394-018-1607-3","article-title":"Is Vitamin D Deficiency a Public Health Concern for Low-Middle-Income Countries? A Systematic Literature Review","volume":"58","author":"Cashman","year":"2019","journal-title":"Eur. J. Nutr."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"550","DOI":"10.1038\/nrendo.2010.146","article-title":"Hypovitaminosis D in Developing Countries\u2014Prevalence, Risk Factors, and Outcomes","volume":"6","author":"Arabi","year":"2010","journal-title":"Nat. Rev. Endocrinol."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"847","DOI":"10.1016\/S2213-8587(18)30265-1","article-title":"Effects of Vitamin D Supplementation on Musculoskeletal Health: A Systematic Review, Meta-Analysis, and Trial Sequential Analysis","volume":"6","author":"Bolland","year":"2018","journal-title":"Lancet Diabetes Endocrinol."},{"key":"ref_48","doi-asserted-by":"crossref","unstructured":"Jung, H.C., Seo, M.W., Lee, S., Kim, S.W., and Song, J.K. (2018). Vitamin D3 Supplementation Reduces the Symptoms of Upper Respiratory Tract Infection during Winter Training in Vitamin D-Insufficient Taekwondo Athletes: A Randomized Controlled Trial. Int. J. Environ. Res. Public Health, 15.","DOI":"10.3390\/ijerph15092003"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1186\/s12970-020-00347-8","article-title":"The Effect of Vitamin D Supplementation on Serum Total 25(OH) Levels and Biochemical Markers of Skeletal Muscles in Runners","volume":"17","author":"Stanula","year":"2020","journal-title":"J. Int. Soc. Sports Nutr."},{"key":"ref_50","doi-asserted-by":"crossref","unstructured":"Michalczyk, M.M., Go\u0142a\u015b, A., Maszczyk, A., Kaczka, P., and Zaj\u0105c, A. (2020). Influence of Sunlight and Oral D3 Supplementation on Serum 25(OH)D Concentration and Exercise Performance in Elite Soccer Players. Nutrients, 12.","DOI":"10.3390\/nu12051311"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"693","DOI":"10.23736\/S0022-4707.18.08551-1","article-title":"Prevalence of Vitamin D Deficiency among Soccer Athletes and Effects of Eight Weeks Supplementation","volume":"59","author":"Teixeira","year":"2019","journal-title":"J. Sports Med. Phys. Fitness"},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"105516","DOI":"10.1016\/j.jsbmb.2019.105516","article-title":"Identification and Analysis of 35 Genes Associated with Vitamin D Deficiency: A Systematic Review to Identify Genetic Variants","volume":"196","author":"Trevino","year":"2020","journal-title":"J. Steroid Biochem. Mol. Biol."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1016\/j.jsbmb.2015.12.007","article-title":"Single Nucleotide Polymorphisms in the Vitamin D Pathway Associating with Circulating Concentrations of Vitamin D Metabolites and Non-Skeletal Health Outcomes: Review of Genetic Association Studies","volume":"164","author":"Jolliffe","year":"2016","journal-title":"J. Steroid Biochem. Mol. Biol."},{"key":"ref_54","doi-asserted-by":"crossref","unstructured":"Usategui-Mart\u00edn, R., De Luis-Rom\u00e1n, D.-A., Fern\u00e1ndez-G\u00f3mez, J.M., Ruiz-Mambrilla, M., and P\u00e9rez-Castrill\u00f3n, J.-L. (2022). Vitamin D Receptor (VDR) Gene Polymorphisms Modify the Response to Vitamin D Supplementation: A Systematic Review and Meta-Analysis. Nutrients, 14.","DOI":"10.3390\/nu14020360"},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1016\/j.gene.2004.05.014","article-title":"Genetics and Biology of Vitamin D Receptor Polymorphisms","volume":"338","author":"Uitterlinden","year":"2004","journal-title":"Gene"},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1016\/j.taap.2018.12.009","article-title":"Alternative Splicing of the Vitamin D Receptor Modulates Target Gene Expression and Promotes Ligand-Independent Functions","volume":"364","author":"Annalora","year":"2019","journal-title":"Toxicol. Appl. Pharmacol."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"e3449","DOI":"10.1002\/jgm.3449","article-title":"TaqI Polymorphism T\/t Genotypes at the Vitamin D Receptor Gene (VDR) Are Associated with Increased Serum Vitamin D Levels in Mild and Moderate Psoriasis Vulgaris: A Pilot Study","volume":"24","author":"AbdElneam","year":"2022","journal-title":"J. Gene Med."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"498","DOI":"10.1002\/jbmr.3008","article-title":"Association Between Single Gene Polymorphisms and Bone Biomarkers and Response to Calcium and Vitamin D Supplementation in Young Adults Undergoing Military Training","volume":"32","author":"Lutz","year":"2017","journal-title":"J. Bone Miner. Res."},{"key":"ref_59","doi-asserted-by":"crossref","unstructured":"Krasniqi, E., Boshnjaku, A., Wagner, K.H., and Wessner, B. (2021). Association between Polymorphisms in Vitamin D Pathway-Related Genes, Vitamin D Status, Muscle Mass, and Function: A Systematic Review. Nutrients, 13.","DOI":"10.3390\/nu13093109"},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"441","DOI":"10.1093\/ajcn\/88.2.441","article-title":"Evidence for Genetic Regulation of Vitamin D Status in Twins with Multiple Sclerosis","volume":"88","author":"Orton","year":"2008","journal-title":"Am. J. Clin. Nutr."},{"key":"ref_61","doi-asserted-by":"crossref","unstructured":"L\u00e1zaro, D., Mielgo-Ayuso, J., Seco-Calvo, J., Guti\u00e9rrez-Abej\u00f3n, E., Roche, E., and Garrosa, M. (2025). Single-Nucleotide Polymorphisms (SNPs) in Vitamin D Physiology Genes May Modulate Serum 25(OH)D Levels in Well-Trained CrossFit\u00ae Athletes, Which May Be Associated with Performance Outcomes. Int. J. Mol. Sci., 26.","DOI":"10.3390\/ijms26125602"},{"key":"ref_62","first-page":"329","article-title":"Effects of Fok-I Polymorphism in Vitamin D Receptor Gene on Serum 25-Hydroxyvitamin D, Bone-Specific Alkaline Phosphatase and Calcaneal Quantitative Ultrasound Parameters in Young Adults","volume":"24","author":"Tanabe","year":"2015","journal-title":"Asia-Pac. J. Clin. Nutr."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"996","DOI":"10.15537\/smj.2016.9.14700","article-title":"Genetic Influence on Circulating Vitamin D among Saudi Arabians","volume":"37","author":"Azam","year":"2016","journal-title":"Saudi Med. 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