Could the Majority of the Greek and Cypriot Population Be Vitamin D Deficient?

Abstract

OBJECTIVE: Hypovitaminosis D is prevalent in epidemic proportions in many developed countries. The aim of this study is to investigate the prevalence of adequate 25-hydroxyvitamin D [25(OH)D] levels in two Mediterranean countries, Greece and Cyprus. METHODS: Data such as 25(OH)D, the month of blood sample collection, and demographic information were blindly collected from 8780 Greek and 2594 Cypriot individuals over 5 years. Comorbidities were also recorded for 839 Greek subjects. Univariate and multivariate analyses were used to examine the relationship between these variables and 25(OH)D levels. RESULTS: In the samples studied, 72.7% of the Greek and 69.3% of the Cypriot population sample had inadequate levels of 25(OH)D. The mean level for the Greek subjects was 25.1 ng/mL and for Cypriots 25.8 ng/mL. For both samples, only month and gender were significantly associated with 25(OH)D levels, and the highest mean levels were recorded in September. For the recorded diseases, the lowest levels were recorded in sickle cell anaemia 13.6 ± 10.2 ng/mL, autoimmune diseases 13.0 ± 8.4 ng/mL, and cancer 22.6 ± 9.5 ng/mL. CONCLUSIONS: The prevalence of vitamin D deficiency is paradoxically high in both Mediterranean countries.

Non-Melanoma Skin Cancer and Vitamin D: The “Lost Sunlight” Paradox and the Oxidative Stress Explanation

“…The mean vitamin D level of our samples was 24.43 ng/mL, with the majority of them being deficient or insufficient (37% of our patients showed deficiency, 35% insufficiency and 28% sufficiency). These findings are in line with Xyda et al [39] who, based on demographic information of a large sample of the Greek population, concluded that the prevalence of vitamin D insufficiency (levels < 30 ng/mL) in the Greek sample was 33%, while 40% of Greeks had vitamin D deficiency (levels < 20 ng/mL). According to a systematic review that focused on the vitamin D levels in individuals, residents of sunny countries revealed a high prevalence of low vitamin D status in the Southern European and the Eastern Mediterranean regions, despite the abundant sunshine [40].…”

Comprehensive Analysis of Seasonal and Geographical Variation in UVB Radiation Relevant for Vitamin D Production in Europe

“…We searched the literature to find studies that report monthly 25(OH)D concentration. We found 15 studies [ 11 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ] and extracted average monthly 25(OH)D concentration. We also calculated mean 25(OH)D for each month in the UK Biobank dataset (data not shown).…”

“…We also calculated mean 25(OH)D for each month in the UK Biobank dataset (data not shown). Studies were classified as (A) healthy/population-based cohorts [ 11 , 17 , 20 , 21 , 23 , 24 , 25 , 26 ], (B) disease cohorts [ 18 , 19 , 22 ], or (C) laboratory samples/database [ 27 , 28 , 29 , 30 ], and analyzed separately. Based on the country the study was conducted in, we used average monthly CW-D-UVB data for the corresponding capital city from our file (except Faroe Islands where the mean between Oslo and Reykjavik was used).…”

“… The relationship between the monthly difference in CW-D-UVB (versus March, the reference month) and the monthly difference in 25(OH)D (versus March, the reference month) for retrieved studies. CW-D-UVB data from this manuscript are used and linked with published reports examining 25(OH)D concentration in ( A ) healthy/population-based cohorts [ 11 , 17 , 20 , 21 , 23 , 24 , 25 , 26 ], ( B ) disease cohorts [ 18 , 19 , 22 ] or ( C ) laboratory samples/database [ 27 , 28 , 29 , 30 ]. Included studies are briefly described in Table S2 .…”