{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,25]],"date-time":"2026-09-25T00:26:34Z","timestamp":1790295994235,"version":"4.1.0"},"reference-count":66,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2025,2,22]],"date-time":"2025-02-22T00:00:00Z","timestamp":1740182400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Knowledge Grant funded this research from the National Science Centre, Poland","award":["2020\/37\/B\/NZ7\/01794"],"award-info":[{"award-number":["2020\/37\/B\/NZ7\/01794"]}]},{"name":"Knowledge Grant funded this research from the National Science Centre, Poland","award":["01-10025\/0008256"],"award-info":[{"award-number":["01-10025\/0008256"]}]},{"name":"Medical University of Gdansk","award":["2020\/37\/B\/NZ7\/01794"],"award-info":[{"award-number":["2020\/37\/B\/NZ7\/01794"]}]},{"name":"Medical University of Gdansk","award":["01-10025\/0008256"],"award-info":[{"award-number":["01-10025\/0008256"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nutrients"],"abstract":"<jats:p>Background: Patients with end-stage chronic diseases, especially those undergoing hemodialysis (HD), often experience mineral bone disease (MBD), leading to hypocalcemia, hyperphosphatemia, and elevated parathyroid hormone (PTH). Vitamin D deficiency and metabolism disorders are also common, resulting from impaired conversion of 25(OH)D3 to its active form, 1,25(OH)2D3, and reduced inactivation to 24,25(OH)2D3. This study aimed to assess the levels of 25(OH)D2, 25(OH)D3, 24,25(OH)2D3, 3-epi-25(OH)D3, and the vitamin D metabolism ratio (VMR) in patients with maintenance HD. Methods: A cross-sectional study was conducted on 66 HD patients (22\u201390 years, average 61.3 \u00b1 16.4), with a control group of 206 adults without chronic kidney disease (CKD), both without cholecalciferol supplementation. Results: the HD patients had significantly lower 25(OH)D3 levels (15 ng\/mL vs. 22 ng\/mL) and higher deficiency rates (69% vs. 39%) compared to the controls. However, both groups showed similarly low levels of optimal vitamin D3. The HD patients had lower 24,25(OH)D3 levels (0.1 vs. 2.1 ng\/mL) and a lower VMR (0.9% vs. 9%). 3-epi-25(OH)D3 levels and its ratio to 25(OH)D3 were significantly lower in the HD group. Alphacalcidol supplementation raised 1,25(OH)2D3 levels (30.4 vs. 16.2 pg\/mL) without affecting other vitamin D metabolites. The HD patients had higher levels of 25(OH)D2 compared to the controls (0.61 vs. 0.31 ng\/mL). Conclusions: Vitamin D3 reserves are lower, and both functional deficiency and impaired catabolism of vitamin D3 are present in HD patients compared to the general population. The VMR index is the most sensitive parameter for vitamin D3 deficiency assessment, highlighting the importance of measuring 24,25(OH)D3. Alphacalcidol supplementation increases 1,25(OH)2D3 levels without affecting other vitamin D metabolites. 25(OH)D2 is the only metabolite that was higher in HD patients than the controls.<\/jats:p>","DOI":"10.3390\/nu17050774","type":"journal-article","created":{"date-parts":[[2025,2,25]],"date-time":"2025-02-25T07:45:08Z","timestamp":1740469508000},"page":"774","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Assessment of Vitamin D Metabolism Disorders in Hemodialysis Patients"],"prefix":"10.3390","volume":"17","author":[{"given":"Maksymilian","family":"Hryciuk","sequence":"first","affiliation":[{"name":"Department of Nephrology, Medical University of Gda\u0144sk, D\u0119binki 7 Street, 80-211 Gda\u0144sk, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3284-0149","authenticated-orcid":false,"given":"Zbigniew","family":"Heleniak","sequence":"additional","affiliation":[{"name":"Department of Nephrology, Medical University of Gda\u0144sk, D\u0119binki 7 Street, 80-211 Gda\u0144sk, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8773-9649","authenticated-orcid":false,"given":"Sylwia","family":"Ma\u0142gorzewicz","sequence":"additional","affiliation":[{"name":"Department of Nephrology, Medical University of Gda\u0144sk, D\u0119binki 7 Street, 80-211 Gda\u0144sk, Poland"},{"name":"Department of Clinical Nutrition, Medical University of Gda\u0144sk, D\u0119binki 7 Street, 80-211 Gda\u0144sk, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Konrad","family":"Kowalski","sequence":"additional","affiliation":[{"name":"Department of Bioenergetics and Exercise Physiology, Medical University of Gda\u0144sk, D\u0119binki 1 Street, 80-211 Gda\u0144sk, Poland"},{"name":"Masdiag Laboratory, S. \u017beromskiego 33 Street, 01-882 Warsaw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J\u0119drzej","family":"Antosiewicz","sequence":"additional","affiliation":[{"name":"Department of Bioenergetics and Exercise Physiology, Medical University of Gda\u0144sk, D\u0119binki 1 Street, 80-211 Gda\u0144sk, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anna","family":"Koelmer","sequence":"additional","affiliation":[{"name":"Centre of Biostatistics and Bioinformatics Analysis, Medical University of Gda\u0144sk, 1a D\u0119binki, 80-211 Gda\u0144sk, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2206-3531","authenticated-orcid":false,"given":"Micha\u0142","family":"\u017bmijewski","sequence":"additional","affiliation":[{"name":"Department of Histology, Medical University of Gda\u0144sk, D\u0119binki 1 Street, 80-211 Gda\u0144sk, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8210-8063","authenticated-orcid":false,"given":"Alicja","family":"D\u0119bska-\u015alizie\u0144","sequence":"additional","affiliation":[{"name":"Department of Nephrology, Medical University of Gda\u0144sk, D\u0119binki 7 Street, 80-211 Gda\u0144sk, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,2,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"443","DOI":"10.1038\/ki.2011.146","article-title":"Three feedback loops precisely regulating serum phosphate concentration","volume":"80","author":"Torres","year":"2011","journal-title":"Kidney Int."},{"key":"ref_2","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. 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