Prevalence of vitamin D deficiency in the population of East Azerbaijan and its relationship with demographic indicators

Abstract

As a fat-soluble vitamin, vitamin D plays a prominent role in the body’s physiological processes, and its deficiency can be the cause of many diseases. Recent studies have shown that demographic indicators are an important tool in determining vitamin D levels. The present study was conducted with the aim of investigating the prevalence of vitamin D deficiency in the population of East Azerbaijan province and its association with demographic indicators. Methods: This cross-sectional study was conducted during 2018 in urban and rural areas of East Azerbaijan province. In this study, 1500 households living in the cities of Tabriz, Marand, Bonab, Oskou, Varzeghan, Khadafarin (150 clusters of 10 households) who were in the same groups as other cities of the province in terms of socio-economic variables and were eligible to enter the study. After obtaining written informed consent from all the subjects, anthropometric indices were collected and questionnaires related to socio-economic and demographic status were completed. At the time of admission, the serum level of vitamin D was measured using the ELISA method. Serum vitamin level more than 30 nm/l was normal, 20-30 nm/l was insufficient and less than 20 nm/l was reported as deficiency. Anthropometric indices were also evaluated and at the end the data was analyzed by SPSS v18. A significance level of less than 0.05 was considered significant. Results: A total of 2816 people were examined in the present study. The age group of 45-55 years was the largest age group in the studied population. In this study, 69.1% of the population had diploma and under-diploma education and 52.9% of the population was unemployed. In total, more than 76.9% of the studied population had various degrees of vitamin D deficiency. The prevalence of normal level of vitamin D in Tabriz city was significantly higher than other cities (P=0.02). Also, the prevalence of vitamin D deficiency in other cities of the province was significantly higher than in Tabriz city (P<0.001). With increasing age up to 45 years, the prevalence of vitamin D deficiency increases and after that it relatively decreases, but the highest prevalence of vitamin D deficiency was observed in the age group between 35 and 45 years. However, no significant difference was observed in any of the classifications between singles and marrieds (P<0.05).