Increased Body Mass Index (BMI) and Sunscreen Use Are Associated with Inadequate Vitamin D Status in Greek Adults in Winter: BMI, Sunscreen Use and Vitamin D Status in Greek Adults

Vitamin D deficiency is common even in sunny countries like Greece, especially during winter and is associated with skeletal disorders and additionally with increased risk for chronic diseases and adipose metabolic diseases such as obesity and diabetes. The purpose of this pilot study was the determination of vitamin D status in Greek adults and the investigation of possible correlation with lifestyles and somatometric characteristics. The study was conducted during winter and included 36 members (20 women and 16 men) of a university community in central Greece (latitude 39.6° North). Their age was 36.2 ± 16.3 years, body mass index (BMI) 26.4 ± 4.8 (women 26.6 ± 5.6, men 26.3 ± 3.8), and waist circumference 85.7 ± 13.3 cm (women 81.5 ± 13.0, men 90.7 ± 12.4) (mean ± SD). Mean serum 25(OH)D concentration was 20.1 ± 7.3 ng/mL (women 19.7 ± 7.6, men 20.7 ± 7.1). More than half of the participants had 25(OH)D levels below the 20 ng/mL (50 nmol/L) threshold of deficiency. There was a significant negative association between the use of sunscreen during summer and serum 25(OH)D concentrations during winter and a significant positive association between physical exercise and serum 25(OH)D. Levels of 25(OH)D tended to decrease with increasing BMI in persons with a BMI over 25.0. There is a high prevalence of vitamin D insufficiency in Greek adults during winter. Serum 25(OH)D levels in winter are positively associated with exercise and negatively associated with high BMI and the use of sunscreen during summer.