Objective: The aim of the present study was to investigate the variations in 25-OH Vitamin D levels based on age, gender, living place, season and presence of chronic disease.
Methods: Individuals whose 25-OH Vitamin D levels were measured in seven state hospitals in Tokat Province of Turkey during September 2016-August 2017 period were determined using hospital information system and included in this retrospective study.
Results: The study included 22,044 individuals who were 18 years of age and over. Vitamin D deficiency and insufficiency was observed in 89.4% of the individuals surveyed. Of all participants, 78.7% (n=17.328) were female and 74.3% (n=16.377) were living in urban areas. Average 25-OH Vitamin D level was significantly low in people living in urban areas (15±12.4 ng/ml) compared to ones in rural areas (15.4±11.5 ng/ml) (p=0.03). Average seasonal 25-OH Vitamin D level was lowest in winter (13.4±11.5 ng/ml) and highest in summer season (17±12.1 ng/ml) (p<0.001). Average 25-OH Vitamin D level was 15.1±12.2 ng/ml, which was significantly higher in men (17.6±9.9 ng/ml) than in women (14.4±12.6 ng/ml) (p<0.001). Average 25-OH Vitamin D level of subjects who did not have a chronic disease was significantly lower than those who had only hypertension, heart disease or multiple sclerosis diagnosis (14.40±11.73, 15.67±12.72, 17.42±13.13 and 19.50±14.88, respectively; p<0.005).
Conclusion: It was found that vitamin D deficiency was associated with living place, age, gender and season of the year. Average 25-OH vitamin D level was significantly higher in individuals with hypertension, heart disease and multiple sclerosis.