Endocrine Abstracts

Introduction: Greek Orthodox monasteries due to their sartorial habits, comprise a population with high prevalence of hypovitaminosis D. Intermittent religious fasting is adopted by this population, as well as from a large part of general lay Greek population. Comparative effects of vitamin D supplementation and intermittent fasting on vitamin D equilibrium and calciotropic profiles remain scarce.

Aim: To comparatively evaluate effects of vitamin D supplementation in two different forms (drops and pills at 2.500 IU daily) in Orthodox nuns from different regions of Greece, versus Orthodox fasting and Western diet patterns in women from general population on vitamin D and calcium homeostasis.

Methods: Two groups of 25 women from two Orthodox monasteries in Northern Greece (Groups A and B) and two groups of 25 healthy women (Groups C and D) were included. During enrollment a detailed recording of demographic, dietary habits and anthropometric characteristics (via bioimpedance) was conducted. We evaluated calciotropic profiles [Calcium-Ca, Albumin, Parathyroid hormone-PTH, 25(OH)D] at baseline and after 12 weeks. Groups A and B received vitamin D supplementation with 2.500 international units of cholecalciferol daily (in the form of drops - Group A- and tablets - Group B). Groups C and D adopted a dietary pattern of Orthodox intermittent fasting [daily feeding window (1000 h–1800 h)] (Group C) and a diet based on the recommendations of the American Heart Association (AHA) for the management of overweight and obesity in adults (Group D).

Results: All groups were comparable at baseline for calcium, PTH and 25(OH)D concentrations. All groups demonstrated significant increases of 25(OH)D [Group A (21.68 vs 31.05 ng/ml),(Group B 25.78 vs 38.35 ng/ml),(Group C 17.31 vs 24.32 ng/ml),(Group D 17.62 vs 24.12 ng/ml), with no significant between group differences. PTH concentrations decreased significantly in Group C (42.18 vs 25.89) pg/ml and Group D (34.22 vs 17.68) pg/ml, whereas PTH changes in groups A and B were non-significant after 12 weeks of supplementation compared to baseline, with no effects of anthropometric measures of body fat,as well as type of supplementation.

Conclusions: Intermittent fasting and AHA dietary patterns were equally effective with equal moderate doses of vitamin D supplementation in improving vitamin D status, in different groups of Greek nuns and lat women.