Karras Spyridon N, Michalakis Konstantinos, Kypraiou Maria, Vlastos Antonios, Anemoulis Marios, Koukoulis Georgios, Mouslech Zadalla, Talidis Filotas, Haitoglou Costas, Michos Georgios, Papanikolaou Evangelos G, Skoutas Dimitrios, Georgopoulos Neoklis, Tzimagiorgis Georgios
Laboratory of Biological Chemistry, Medical School, Aristotle University, 54124 Thessaloniki, Greece.
Department of Obesity and Metabolism, 11521 Athens, Greece.
Nutrients. 2025 May 13;17(10):1656. doi: 10.3390/nu17101656.
Vitamin D plays a key role in bone metabolism and immune regulation. Populations with restricted sun exposure or limited dietary intake are particularly vulnerable to vitamin D deficiency. Orthodox Christian nuns represent a unique group in this regard, due to traditional clothing, limited outdoor activity, and prolonged religious fasting. However, few studies have compared them with lay individuals following similar dietary practices. This study aimed to investigate predictors of serum 25-hydroxyvitamin D [25(OH)D] concentrations in two female populations: Orthodox Christian nuns and women from the general population practicing intermittent (religious or non-religious) fasting. We also aimed to develop predictive models of vitamin D status for each group based on lifestyle and biochemical parameters. A total of 85 women (40 Orthodox nuns and 45 laywomen), aged 30-50 years, were enrolled. Serum 25(OH)D, parathyroid hormone (PTH), calcium levels, and anthropometric indices, including body mass index (BMI), total body fat, and visceral fat, were measured. Dietary calcium and vitamin D intake, as well as sun exposure, were assessed using validated questionnaires. Separate stepwise multiple regression models were constructed for each group to identify independent predictors of 25(OH)D concentrations. An additional combined model, including all participants, was also explored. PTH was the most significant predictor, negatively correlating with 25(OH)D concentrations in both groups ( = 0.038), highlighting its regulatory role in vitamin D metabolism. When analyzed separately, the model for Orthodox nuns showed stronger explanatory power (adjusted R = 0.718; = 0.013) compared with the control group (adjusted R = 0.362; = 0.038), with PTH emerging as a key predictor in both. Distinct predictors of vitamin D status were identified in each group, reflecting the complex interplay between lifestyle and physiological factors. These findings suggest that targeted interventions, such as addressing PTH regulation in fasting populations or enhancing sun exposure in the general population, may be more effective in preventing vitamin D deficiency depending on the context.
维生素D在骨骼代谢和免疫调节中起关键作用。阳光照射受限或饮食摄入有限的人群尤其容易缺乏维生素D。东正教修女在这方面是一个独特的群体，因为她们身着传统服饰、户外活动有限且长期进行宗教禁食。然而，很少有研究将她们与遵循类似饮食习惯的非修女个体进行比较。本研究旨在调查两个女性群体中血清25-羟基维生素D[25(OH)D]浓度的预测因素：东正教修女和来自普通人群且进行间歇性（宗教或非宗教）禁食的女性。我们还旨在基于生活方式和生化参数为每组建立维生素D状态的预测模型。共招募了85名年龄在30至50岁之间的女性（40名东正教修女和45名非修女女性）。测量了血清25(OH)D、甲状旁腺激素（PTH）、钙水平以及人体测量指标，包括体重指数（BMI）、全身脂肪和内脏脂肪。使用经过验证的问卷评估饮食中钙和维生素D的摄入量以及阳光照射情况。为每组构建单独的逐步多元回归模型，以确定25(OH)D浓度的独立预测因素。还探索了一个包括所有参与者的综合模型。PTH是最显著的预测因素，在两组中均与25(OH)D浓度呈负相关（=0.038），突出了其在维生素D代谢中的调节作用。单独分析时，东正教修女组的模型显示出比对照组更强的解释力（调整后R=0.718；=0.013），而对照组的调整后R=0.362；=0.038，PTH在两组中均为关键预测因素。在每组中都确定了维生素D状态的不同预测因素，反映了生活方式和生理因素之间复杂的相互作用。这些发现表明，针对性的干预措施，如解决禁食人群中的PTH调节问题或增加普通人群的阳光照射，根据具体情况可能在预防维生素D缺乏方面更有效。
