Study on Association between BMI and Vitamin D Levels in South Indian Rural Population

Introduction: Vitamin D deficiency is a global health problem worldwide and is considered to be a pandemic with implications for compromised bone health and other chronic diseases. A few studies have examined the association between vitamin D status and body mass index (BMI). However, prospective data using the biomarker serum 25-hydroxyvitamin D 25(OH) D3 are limited and therefore examined in the present study. This study aims to evaluate the level of vitamin D status among healthy individuals and also to examine the relation between BMI and 25(OH)D in a cross-sectional sample of 100 men and women ranging in age from 18-75 years. Methods: Participants were selected from subjects attending to Medicine Outpatient Department (OPD) in Sri Venkateshwara Medical College Hospital & Research Centre (SVMCH & RC) willing to participate in the present study between Jan 2020 to Dec 2020. Anthropometric measurements, personal, medical history questionnaire, food frequency questionnaire (FFQ) for vitamin D, and sun exposure questionnaire were collected from all the participants in the present study, blood samples for serum 25(OH)D3 were collected from all subjects. Results: Our study showed that the majority of healthy individual cases of the study i.e., 68.0% have a deficiency in vitamin D status, while 68.0% have ≤20 ng/dl in vitamin D, and 32.0% in >20 ng/dl. Moreover, the study showed a negative association between the level of circulating 25(OH) D3 and BMI. There is a statistically significant and inverse correlation between the level of circulating 25(OH) D3 and BMI. Conclusion: This study demonstrated that the association between BMI and 25(OH)D concentrations in populations from south India can be seen across different age groups and in both men and women. The study also exemplified that higher BMI leads to lower vitamin D status, providing evidence for the role of obesity as a causal risk factor for the development of vitamin D deficiency.