{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,9]],"date-time":"2026-06-09T13:53:05Z","timestamp":1781013185914,"version":"3.54.1"},"reference-count":30,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2025,11,26]],"date-time":"2025-11-26T00:00:00Z","timestamp":1764115200000},"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>Background<\/jats:title>\n                    <jats:p>Vitamin D deficiency is highly prevalent in populations following intermittent or religious fasting, particularly Orthodox nuns with limited sun exposure and dietary restrictions. Vitamin D may modulate adipokines and inflammatory markers, but clinical evidence remains inconsistent.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>To investigate the effects of vitamin D supplementation on interleukin-6 (IL-6) and leptin concentrations in Orthodox nuns compared with non-supplemented controls.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>\n                      In this controlled, non-randomized trial, 33 Orthodox nuns received oral vitamin D\n                      <jats:sub>3<\/jats:sub>\n                      supplementation (2,500 IU\/day) for 16 weeks, while 42 age-matched women following Orthodox intermittent fasting served as controls. Anthropometric indices and serum concentrations of 25-hydroxyvitamin D [25(OH)D], IL-6, leptin, parathyroid hormone, insulin, and C-reactive protein were measured at baseline and follow-up.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      At baseline, serum 25(OH)D concentrations were lower in the supplementation group compared with controls (23.4 \u00b1 10.1\n                      <jats:italic>vs<\/jats:italic>\n                      . 27.7 \u00b1 11.2 ng\/mL,\n                      <jats:italic>p<\/jats:italic>\n                      = 0.043). After 16 weeks, 25(OH)D increased significantly in the supplementation group (23.4 \u00b1 10.1\n                      <jats:italic>vs<\/jats:italic>\n                      . 33.9 \u00b1 11.0 ng\/mL,\n                      <jats:italic>p<\/jats:italic>\n                      &amp;lt; 0.001), with no change in controls (27.7 \u00b1 11.2\n                      <jats:italic>vs<\/jats:italic>\n                      . 28.5 \u00b1 12.2 ng\/mL,\n                      <jats:italic>p<\/jats:italic>\n                      = 0.941). Leptin showed a non-significant decrease in the supplementation group (24.4 \u00b1 18.3\n                      <jats:italic>vs<\/jats:italic>\n                      . 21.9 \u00b1 13.5 ng\/mL,\n                      <jats:italic>p<\/jats:italic>\n                      = 0.215), whereas in the controls, it remained unchanged (23.21 \u00b1 14.67\n                      <jats:italic>vs<\/jats:italic>\n                      . 24.05 \u00b1 13.89 pg\/mL,\n                      <jats:italic>p<\/jats:italic>\n                      = 0.365). IL-6 did not change significantly in either group. Exploratory multivariable regression did not reveal significant predictors of leptin changes.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Vitamin D supplementation effectively corrected deficiency but did not significantly affect leptin or IL-6 concentrations. These results highlight the need for larger and longer studies to further clarify the immunometabolic impact of vitamin D supplementation in women practicing intermittent fasting.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fendo.2025.1700844","type":"journal-article","created":{"date-parts":[[2025,11,26]],"date-time":"2025-11-26T05:16:03Z","timestamp":1764134163000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":2,"title":["Vitamin D supplementation and its impact on leptin and interleukin-6 in women following religious intermittent fasting: a controlled study"],"prefix":"10.3389","volume":"16","author":[{"given":"Spyridon 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