The Survey of the prevalence of vitamin D deficiency and its association with lifestyle patterns and nutrient pattern in adults in Tabriz

Abstract

Backgrounds and Aims: Vitamin D deficiency is one of the major health problems and has a high unexpected prevalence in developed and developing countries. The status of serum vitamin D varies in different societies and geographical locations, one of the reasons being the diversity of people's lifestyles. Several studies have examined the association between lifestyle components such as diet, physical activity, and smoking with vitamin D deficiency separately but, there is no study to investigate the relationship between lifestyle and nutrient patterns with status of vitamin D. Considering the high prevalence of vitamin D deficiency in Iran, the present study was conducted to determine the prevalence of vitamin D deficiency and its relationship with lifestyle patterns and nutrient patterns in an adult population of north-west of Iran. Methods: The data of 530 subjects (214 men and 316 women) as a part of the major Lifestyle Promotion Project (LPP) conducted in the districts of Tabriz-East Azerbaijan-Iran were collected for this study. Anthropometric assessments were performed and body mass index (BMI) and waist to hip ratio (WHR) were calculated. Biochemical assays were performed after 10-12 hours fasting include vitamin D, FBS and lipid profile. Serum level of vitamin D was measured by ELISA method. Dietary and nutrient patterns were derived by factor analysis using a validated food frequency questionnaire (FFQ) and lifestyle patterns were obtained using latant class analysis (LCA) based on the clustering of three modifiable lifestyle risk factors: dietary pattern, physical activity, and smoking habits. Results: The mean of age was 42.90 ± 11.89 years. The mean ± SD of serum 25(OH)D levels was 23.33 ± 11.24 ng/mL, and 52% of the participants were vitamin D-deficient (< 20 ng/mL); 25.28% were vitamin D-insufficient (20-30 ng/mL), and 22.65% had normal vitamin D levels (>30 ng/mL). Dietary patterns including Western, healthy and traditional were determind, using factor analysis. Western dietary pattern was the most consumed one among the study participants (36.98%). Also, three nutrient patterns (mixed-source, animal-sourced and plant-sourced) were identified, using factor analysis. In this study, three classes of lifestyle patterns were identified. About 26% of participants were categorized in a low-risk class (I), 15.5% in an intermediate-risk class (239), and 58.5% in a high-risk class (III) of lifestyle. Smoking as a behavioral risk factor was not a good indicator to describe the classes because 88.5% of the participants did not smoke. Furthermore, we observed no significant difference between the lifestyle patterns in regards to mean vitamin D level (P> 0.05) but in terms of BMI, WHR, FBS and anxiety there was a significant difference between lifestyle patterns (P <0.05). BMI WHR, fasting blood sugar and anxiety were higher in participants with unhealthy lifestyles than others. Also, there was no significant difference in serum vitamin D levels between different quartiles of nutrient patterns (P> 0.05) but there was a significant difference in quartiles of animal-sourced nutrient pattern in terms of weight, TG, HDL-C and education (P <0.05) and there was a significant difference in terms of age, weight, WC, FBS, TG and LDL-C between quartiles of plant-sourced nutrient pattern (P <0.05). Conclusions: The results of this study indicate a high prevalence of vitamin D deficiency in the participants under study; particularly in women, so in addition to treatment of this group, it is necessary to increase the awareness of participants to change and improve lifestyle, especially diet, physical activity more and exposure to sunlight. This study helps to identify people's lifestyle patterns and provides evidence that there are considerable differences in lifestyle behaviors between subgroups of adults. According to the results of the present study, a small percentage of individuals was in the healthy lifestyle cluster (26%) and most of the participants had an unhealthy lifestyle pattern, western dietary pattern (36.98%) and low physical activity level (36.60%).Health policy-makers should pay more attention to physical activity and dietand by targeting these behaviors, prevent high-risk behaviors associated with vitamin D deficiency.