Predictors of Vitamin D Status in Religious and Intermittent Fasting: A Comparative Study in Orthodox Nuns and Women from the General Population
Abstract
1. Introduction
2. Methods
2.1. Design
2.2. Study Populations
2.3. Dietary Regimens
2.4. Anthropometric and Biochemical Assessment
2.5. Dietary Intake and Sun Exposure
2.6. Statistical Analysis
- Model 1: Demographic and anthropometric parameters (age, BMI, calcium and vitamin D intake, and sun exposure);
- Model 2: Model 1 plus total and visceral fat, as obtained by BIA analysis;
- Model 3: Μodel 2 plus PTH and insulin concentrations.
3. Results
4. Discussion
5. Conclusions
Supplementary Materials
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
References
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Variable | Monastic Group (n = 40) | General Population (n = 45) | p-Value |
---|---|---|---|
Age (years) | 52.4 ± 17.5 | 49.6 ± 14.3 | 0.314 |
Years in monastery (years) | 18.6 ± 14.1 | — | — |
Calcium intake (mg/day) | 467.5 ± 34 | 678 ± 69 | 0.034 |
Vitamin D intake (IU/day) | 245 ± 11 | 267 ± 18 | 0.23 |
Sunshine exposure (hours/week) | 4.23 ± 1.2 | 11.2 ± 3.8 | <0.01 |
BMI | 27.3 ± 4.9 | 25.9 ± 3.8 | 0.151 |
Body fat (%) | 36.0 ± 7.8 | 34.1 ± 6.1 | 0.220 |
Visceral fat | 7.7 ± 3.9 | 6.1 ± 2.7 | 0.031 |
Insulin (μIU/mL) | 11.3 ± 10.6 | 8.4 ± 6.9 | 0.081 |
PTH (pg/mL) | 42.0 ± 15.1 | 24.6 ± 8.2 | <0.01 |
25(OH)D (ng/mL) | 22.5 ± 8.7 | 26.4 ± 9.1 | 0.062 |
Glucose (mg/dL) | 92.4 ± 9.5 | 89.8 ± 8.7 | 0.129 |
Calcium (mg/dL) | 9.1 ± 0.3 | 9.4 ± 0.3 | 0.914 |
Phosphate (mg/dL) | 3.7 ± 0.5 | 3.9 ± 0.4 | 0.087 |
Predictor | Coefficient | p-Value |
---|---|---|
Age (years) | 0.064 | 0.665 |
BMI | 3.015 | 0.210 |
Calcium intake (mg/d) | 0.980 | 0.435 |
Vitamin D intake (IU/d) | 0.142 | 0.123 |
Sunshine exposure (h/w) | 1.381 | 0.171 |
Calcium (mg/dL) | 0.054 | 0.779 |
Phosphate (mg/dL) | −0.217 | 0.528 |
Predictor | Coefficient | p-Value |
---|---|---|
Age (years) | −0.726 | 0.215 |
BMI | −0.055 | 0.985 |
Calcium intake (mg/d) | 0.812 | 0.061 |
Vitamin D intake (IU/d) | 0.143 | 0.056 |
Sunshine exposure (h/w) | 0.109 | 0.064 |
Calcium (mg/dL) | 0.123 | 0.708 |
Phosphate (mg/dL) | −0.278 | 0.412 |
Body fat (%) | −1.571 | 0.101 |
Visceral fat | 7.495 | 0.140 |
Predictor | Orthodox Nuns β (p-Value) | General Population β (p-Value) |
---|---|---|
Age (years) | −0.032 (0.784) | −0.017 (0.852) |
BMI | −0.044 (0.725) | −0.039 (0.791) |
Calcium intake (mg/day) | 0.129 (0.214) | 0.119 (0.178) |
Vitamin D intake (IU/day) | 0.086 (0.341) | 0.101 (0.229) |
Sun exposure (h/week) | 0.121 (0.261) | 0.144 (0.191) |
Calcium (mg/dL) | 0.045 (0.737) | 0.061 (0.698) |
Phosphate (mg/dL) | −0.084 (0.611) | −0.112 (0.493) |
Body fat (%) | −0.091 (0.438) | −0.073 (0.502) |
Visceral fat | 0.115 (0.301) | 0.132 (0.227) |
Insulin (μIU/mL) | 0.398 (0.422) | 0.790 (0.231) |
PTH (pg/mL) | −0.489 (0.013) | −0.549 (0.038) |
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Karras, S.N.; Michalakis, K.; Kypraiou, M.; Vlastos, A.; Anemoulis, M.; Koukoulis, G.; Mouslech, Z.; Talidis, F.; Haitoglou, C.; Michos, G.; et al. Predictors of Vitamin D Status in Religious and Intermittent Fasting: A Comparative Study in Orthodox Nuns and Women from the General Population. Nutrients 2025, 17, 1656. https://doi.org/10.3390/nu17101656
Karras SN, Michalakis K, Kypraiou M, Vlastos A, Anemoulis M, Koukoulis G, Mouslech Z, Talidis F, Haitoglou C, Michos G, et al. Predictors of Vitamin D Status in Religious and Intermittent Fasting: A Comparative Study in Orthodox Nuns and Women from the General Population. Nutrients. 2025; 17(10):1656. https://doi.org/10.3390/nu17101656
Chicago/Turabian StyleKarras, Spyridon N., Konstantinos Michalakis, Maria Kypraiou, Antonios Vlastos, Marios Anemoulis, Georgios Koukoulis, Zadalla Mouslech, Filotas Talidis, Costas Haitoglou, Georgios Michos, and et al. 2025. "Predictors of Vitamin D Status in Religious and Intermittent Fasting: A Comparative Study in Orthodox Nuns and Women from the General Population" Nutrients 17, no. 10: 1656. https://doi.org/10.3390/nu17101656
APA StyleKarras, S. N., Michalakis, K., Kypraiou, M., Vlastos, A., Anemoulis, M., Koukoulis, G., Mouslech, Z., Talidis, F., Haitoglou, C., Michos, G., Papanikolaou, E. G., Skoutas, D., Georgopoulos, N., & Tzimagiorgis, G. (2025). Predictors of Vitamin D Status in Religious and Intermittent Fasting: A Comparative Study in Orthodox Nuns and Women from the General Population. Nutrients, 17(10), 1656. https://doi.org/10.3390/nu17101656