{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,21]],"date-time":"2026-10-21T03:02:04Z","timestamp":1792551724993,"version":"4.5.0"},"reference-count":40,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,6,4]],"date-time":"2026-06-04T00:00:00Z","timestamp":1780531200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Endocrinol."],"abstract":"<jats:sec>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>25-hydroxyvitamin D [25(OH)D] deficiency is highly prevalent in type 2 diabetes mellitus (T2DM) and may contribute to immune and metabolic dysfunction. This study aimed to investigate the clinical associations of serum 25(OH)D levels with calcium metabolism, inflammation, thyroid function, and autoimmunity in patients with T2DM.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>This cross-sectional study enrolled 503 patients with T2DM, stratified into four groups based on 25(OH)D levels: severe deficiency (&amp;lt;10 ng\/mL), moderate deficiency (10\u201320 ng\/mL), insufficiency (20\u201330 ng\/mL), and sufficiency (&amp;gt;30 ng\/mL). Clinical and biochemical parameters were compared across groups and between thyroid autoantibody (TPOAb\/TGAb) positive and negative subgroups. A multiple linear regression model identified independent predictors of 25(OH)D levels.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>25(OH)D deficiency (&amp;lt;20 ng\/mL) was present in 83.7% of patients. Higher 25(OH)D levels correlated with lower PTH (P\u00a0=\u00a00.010) and higher calcium (P&amp;lt;0.001). hsCRP peaked in the moderate deficiency group (2.66 mg\/L, P&amp;lt;0.001). T3 and fT3 peaked in the insufficiency group and were lowest in severe deficiency (P&amp;lt;0.05). TGAb positivity was associated with higher 25(OH)D levels (13.45 vs. 12.00 ng\/mL, P\u00a0=\u00a00.008), whereas TPOAb positivity was associated with lower levels (11.90 vs. 12.85 ng\/mL, P&amp;lt;0.001). No significant associations were found with HbA1c, BMI, TSH, or bone markers.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>In patients with T2DM, 25(OH)D deficiency is highly prevalent and independently associated with altered calcium-PTH homeostasis, elevated inflammation, and suppressed T3 levels. The opposing relationships with TGAb and TPOAb suggest complex interactions between vitamin D and thyroid autoimmunity in this population.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fendo.2026.1867755","type":"journal-article","created":{"date-parts":[[2026,6,4]],"date-time":"2026-06-04T04:33:40Z","timestamp":1780547620000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":1,"title":["Association of 25(OH)D status with calcium metabolism, inflammation, and thyroid autoimmunity in patients with type 2 diabetes mellitus"],"prefix":"10.3389","volume":"17","author":[{"given":"Nannan","family":"Lv","sequence":"first","affiliation":[{"name":"Department of Endocrinology and Metabolism, The Fourth People\u2019s Hospital of Shenyang, China Medical University","place":["Shenyang, Liaoning, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jianjian","family":"Xiang","sequence":"additional","affiliation":[{"name":"Department of Ultrasound Medicine, The First Affiliated Hospital, Zhejiang University School of Medicine","place":["Hangzhou, Zhejiang, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jinsong","family":"Kuang","sequence":"additional","affiliation":[{"name":"Department of Endocrinology and Metabolism, The Fourth People\u2019s Hospital of Shenyang, China Medical University","place":["Shenyang, Liaoning, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fei","family":"Liu","sequence":"additional","affiliation":[{"name":"Department of Endocrinology and Metabolism, The Fourth People\u2019s Hospital of Shenyang, China Medical University","place":["Shenyang, Liaoning, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lan","family":"Cheng","sequence":"additional","affiliation":[{"name":"Department of Endocrinology and Metabolism, The Fourth People\u2019s Hospital of Shenyang, China Medical University","place":["Shenyang, Liaoning, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shanyu","family":"Yin","sequence":"additional","affiliation":[{"name":"Department of Ultrasound Medicine, The First Affiliated Hospital, Zhejiang University School of Medicine","place":["Hangzhou, Zhejiang, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,6,4]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"789","DOI":"10.1210\/er.2018-00163","article-title":"Thyroid dysfunction and diabetes mellitus: Two closely associated disorders","volume":"40","author":"Biondi","year":"2019","journal-title":"Endocr Rev"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.4093\/dmj.2022.0013","article-title":"Links between thyroid disorders and glucose homeostasis","volume":"46","author":"Eom","year":"2022","journal-title":"Diabetes Metab J"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.1101\/gad.346312.120","article-title":"Chronic tissue inflammation and metabolic disease","volume":"35","author":"Lee","year":"2021","journal-title":"Genes Dev"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1038\/s41574-025-01226-5","article-title":"The public health burden of diabetes mellitus and thyroid disease: Twin epidemics","volume":"22","author":"Razvi","year":"2026","journal-title":"Nat Rev Endocrinol"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.3390\/diabetology6050041","article-title":"The intricate relationship between thyroid disorders and type 2 diabetes\u2014a narrative review","volume":"6","author":"Tilici","year":"2025","journal-title":"Diabetology"},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.3390\/biomedicines13102364","article-title":"Intersecting endocrine pathways in cardiomyopathy: The role of metabolic burden in structural heart disease","volume":"13","author":"\u021aica","year":"2025","journal-title":"Biomedicines"},{"key":"B7","doi-asserted-by":"publisher","first-page":"3332","DOI":"10.1038\/s41467-025-58721-6","article-title":"Vitamin D supplementation vs. placebo and incident type 2 diabetes in an ancillary study of the randomized Vitamin D and Omega-3 Trial","volume":"16","author":"Tobias","year":"2025","journal-title":"Nat Commun"},{"key":"B8","doi-asserted-by":"publisher","DOI":"10.1016\/j.tem.2024.04.018","article-title":"Vitamin D and major chronic diseases","volume":"35","author":"Zhao","year":"2024","journal-title":"Trends Endocrinol Metab"},{"key":"B9","doi-asserted-by":"publisher","DOI":"10.3390\/ijms24044080","article-title":"Vitamin D metabolism and its role in temporomandibular joint osteoarthritis and autoimmune thyroid diseases","volume":"24","author":"Szulc","year":"2023","journal-title":"Int J Mol Sci"},{"key":"B10","doi-asserted-by":"publisher","DOI":"10.3390\/nu11040794","article-title":"Analysis of association between vitamin D deficiency and insulin resistance","volume":"11","author":"Szymczak-Pajor","year":"2019","journal-title":"Nutrients"},{"key":"B11","doi-asserted-by":"publisher","DOI":"10.1093\/advances\/nmaa161","article-title":"Impacts of selected dietary nutrient intakes on skeletal muscle insulin sensitivity and applications to early prevention of type 2 diabetes","volume":"12","author":"Zhang","year":"2021","journal-title":"Adv Nutr"},{"key":"B12","doi-asserted-by":"publisher","DOI":"10.3390\/nu15143174","article-title":"Impact of vitamin D on immunopathology of Hashimoto's thyroiditis: From theory to practice","volume":"15","author":"Lebiedzi\u0144ski","year":"2023","journal-title":"Nutrients"},{"key":"B13","doi-asserted-by":"publisher","DOI":"10.4239\/wjd.v15.i2.209","article-title":"Vitamin D, selenium, and antidiabetic drugs in the treatment of type 2 diabetes mellitus with Hashimoto's thyroiditis","volume":"15","author":"Feng","year":"2024","journal-title":"World J Diabetes"},{"key":"B14","doi-asserted-by":"publisher","DOI":"10.14740\/jocmr3507w","article-title":"Low vitamin D deficiency associated with thyroid disease among type 2 diabetic mellitus patients","volume":"10","author":"Bener","year":"2018","journal-title":"J\u00a0Clin Med Res"},{"key":"B15","doi-asserted-by":"publisher","DOI":"10.2337\/dc14-S014","article-title":"Standards of medical care in diabetes--2014","volume":"37","year":"2014","journal-title":"Diabetes Care"},{"key":"B16","doi-asserted-by":"publisher","DOI":"10.4183\/aeb.2019.102","article-title":"Hypovitaminosis D in HIV-infected patients","volume":"15","author":"Poiana","year":"2019","journal-title":"Acta Endocrinol (Bucharest)"},{"key":"B17","doi-asserted-by":"publisher","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":"B18","doi-asserted-by":"publisher","DOI":"10.3803\/EnM.2020.826","article-title":"Association of vitamin D deficiency with diabetic nephropathy","volume":"36","author":"Hong","year":"2021","journal-title":"Endocrinol Metab (Seoul)"},{"key":"B19","doi-asserted-by":"publisher","DOI":"10.3389\/fnut.2024.1462535","article-title":"The prevention and improvement effects of vitamin D on type 2 diabetes mellitus: Evidence from an umbrella review on meta-analyses of cohort studies and randomized controlled trials","volume":"11","author":"Cheng","year":"2024","journal-title":"Front Nutr"},{"key":"B20","doi-asserted-by":"publisher","first-page":"6454","DOI":"10.1038\/s41598-025-90785-8","article-title":"Association between serum vitamin D level and cardiovascular disease in Chinese patients with type 2 diabetes mellitus: A cross-sectional study","volume":"15","author":"Zhang","year":"2025","journal-title":"Sci Rep"},{"key":"B21","doi-asserted-by":"publisher","DOI":"10.2147\/DMSO","article-title":"Vitamin D status and cardiovascular risk factors in patients with type 2 diabetes mellitus: A cross-sectional study in a tertiary-level hospital in Antananarivo, Madagascar","volume":"17","author":"Raharinavalona","year":"2024","journal-title":"Diabetes Metab Syndr Obes"},{"key":"B22","doi-asserted-by":"publisher","first-page":"561","DOI":"10.1002\/cphy.c140071","article-title":"PTH and vitamin D","volume":"6","author":"Khundmiri","year":"2016","journal-title":"Compr Physiol"},{"key":"B23","doi-asserted-by":"publisher","DOI":"10.3390\/nu10121890","article-title":"The emerging role of nutritional vitamin D in secondary hyperparathyroidism in CKD","volume":"10","author":"Lu","year":"2018","journal-title":"Nutrients"},{"key":"B24","doi-asserted-by":"publisher","DOI":"10.3390\/ijms24043751","article-title":"Vitamin D and diabetic kidney disease","volume":"24","author":"Huang","year":"2023","journal-title":"Int J Mol Sci"},{"key":"B25","doi-asserted-by":"publisher","DOI":"10.3389\/fnut.2025.1509465","article-title":"Decreased vitamin D increase the risk for subclinical hypothyroidism in individuals with T2DM: A cross-sectional study","volume":"12","author":"Fang","year":"2025","journal-title":"Front Nutr"},{"key":"B26","doi-asserted-by":"publisher","DOI":"10.1016\/j.jnha.2024.100446","article-title":"Interactions between vitamin D deficiency and inflammation on diabetes risk: Data from 336,500 UK Biobank adults","volume":"29","author":"Kositsawat","year":"2025","journal-title":"J Nutr Health Aging"},{"key":"B27","doi-asserted-by":"publisher","DOI":"10.1210\/clinem\/dgab649","article-title":"Effects of vitamin D supplementation on insulin sensitivity and secretion in prediabetes","volume":"107","author":"Rasouli","year":"2022","journal-title":"J Clin Endocrinol Metab"},{"key":"B28","doi-asserted-by":"publisher","DOI":"10.3389\/fphys.2021.722912","article-title":"Vitamin D, thyroid hormones and cardiovascular risk: Exploring the components of this novel disease triangle","volume":"12","author":"Vassalle","year":"2021","journal-title":"Front Physiol"},{"key":"B29","doi-asserted-by":"publisher","first-page":"171","DOI":"10.1186\/s12902-021-00831-5","article-title":"Vitamin D and thyroid disorders: A systematic review and meta-analysis of observational studies","volume":"21","author":"Taheriniya","year":"2021","journal-title":"BMC Endocr Disord"},{"key":"B30","doi-asserted-by":"publisher","DOI":"10.7759\/cureus.25869","article-title":"Association between vitamin D deficiency and autoimmune thyroid disorder: A systematic review","volume":"14","author":"Khozam","year":"2022","journal-title":"Cureus"},{"key":"B31","doi-asserted-by":"publisher","DOI":"10.1007\/s00394-019-01991-w","article-title":"Serum 25-hydoxyvitamin D concentrations in relation to Hashimoto\u2019s thyroiditis: A systematic review, meta-analysis and meta-regression of observational studies","volume":"59","author":"\u0160tefanic","year":"2020","journal-title":"Eur J Nutr"},{"key":"B32","doi-asserted-by":"publisher","DOI":"10.4158\/EP14191.OR","article-title":"Low vitamin D status is associated with increased thyrotropin-receptor antibody titer in Graves disease","volume":"21","author":"Zhang","year":"2015","journal-title":"Endocr Pract"},{"key":"B33","doi-asserted-by":"publisher","DOI":"10.3390\/ijerph13090850","article-title":"25 hydroxyvitamin D deficiency and its relationship to autoimmune thyroid disease in the elderly","volume":"13","author":"Muscogiuri","year":"2016","journal-title":"Int J Environ Res Public Health"},{"key":"B34","doi-asserted-by":"publisher","first-page":"775","DOI":"10.1186\/s12888-023-05274-x","article-title":"Relationship between serum vitamin D and thyroid hormone profiles in male patients with alcohol dependence","volume":"23","author":"Liu","year":"2023","journal-title":"BMC Psychiatry"},{"key":"B35","doi-asserted-by":"publisher","DOI":"10.1155\/ije\/1918396","article-title":"Association between serum G protein-coupled estrogen receptor and the peripheral blood balance of T-helper\/new effector T-cells in patients with Hashimoto's thyroiditis","volume":"2025","author":"Zang","year":"2025","journal-title":"Int J Endocrinol"},{"key":"B36","doi-asserted-by":"publisher","first-page":"62","DOI":"10.1038\/s41590-021-01080-3","article-title":"Autocrine vitamin D signaling switches off pro-inflammatory programs of TH1 cells","volume":"23","author":"Chauss","year":"2022","journal-title":"Nat Immunol"},{"key":"B37","doi-asserted-by":"publisher","DOI":"10.14260\/jemds\/2017\/666","article-title":"Study of the association of serum 25-hydroxyvitamin D levels with the glycaemic control in type 2 diabetes mellitus at a tertiary care hospital in Goa","volume":"6","author":"Nayak","year":"2017","journal-title":"J Evol Med Dent Sci"},{"key":"B38","doi-asserted-by":"publisher","DOI":"10.1097\/MD.0000000000037291","article-title":"Determinants of vitamin D deficiency among type 2 diabetes mellitus patients: A retrospective study","volume":"103","author":"Alzahrani","year":"2024","journal-title":"Med (Baltimore)"},{"key":"B39","doi-asserted-by":"publisher","DOI":"10.1186\/s12902-015-0003-8","article-title":"Does vitamin D play a significant role in type 2 diabetes","volume":"15","author":"Sheth","year":"2015","journal-title":"BMC Endocr Disord"},{"key":"B40","doi-asserted-by":"publisher","DOI":"10.3389\/fendo.2025.1650525","article-title":"Correlation analysis of thyroid function and vitamin D levels in patients with type 2 diabetes","volume":"16","author":"Wu","year":"2025","journal-title":"Front Endocrinol (Lausanne)"}],"container-title":["Frontiers in Endocrinology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fendo.2026.1867755\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,6,4]],"date-time":"2026-06-04T04:33:49Z","timestamp":1780547629000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fendo.2026.1867755\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,6,4]]},"references-count":40,"alternative-id":["10.3389\/fendo.2026.1867755"],"URL":"https:\/\/doi.org\/10.3389\/fendo.2026.1867755","relation":{},"ISSN":["1664-2392"],"issn-type":[{"value":"1664-2392","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,6,4]]},"article-number":"1867755"}}