Comparison of vitamin D status in healthy Bangladeshi urban and rural individuals and their association with serum calcium and alkaline phosphatase: A pilot study.

Vitamin D insufficiency is a worldwide problem that is likely underestimated since physical symptoms may only be apparent in individuals with severe deficiencies. Previously, people in South Asian countries were thought to be vitamin D sufficient because of plentiful sunshine, but vitamin D insufficiency has also been reported in these countries. In a South Asian country like Bangladesh, people living in the rural and urban parts of the country can have considerable differences in their sun exposure, types of clothing worn, and levels of air pollution. This pilot study aimed to explore the vitamin D status (measured by serum 25[OH]D) of healthy urban and rural Bangladeshi people and to examine the association of serum 25(OH)D concentration with calcium and alkaline phosphatase concentrations. A total of 101 apparently healthy adult individuals, aged 20-58 years, were enrolled from both urban and rural areas. The participants were selected from students, staff and patient attendants from the outpatient department (OPD) of Bangabandhu Sheikh Mujib Medical University and Mirsarai Upazila Health Complex, Chittagong. The overall rate of vitamin D insufficiency was 39.6% and of vitamin D deficiency was 51.5%. However, it was observed that the proportion of vitamin D-deficient participants in urban areas (70.6%) was more than double that of participants living in rural areas (32%) and that serum 25(OH)D concentrations were higher in rural compared to urban participants with similar sunlight exposure times. However, participants aged 50 years or more showed similar concentrations of serum vitamin D levels irrespective of their habitat. This pilot study highlights the need for further larger-scale studies in Bangladesh to determine the reasons for the high rates of vitamin D inadequacy overall and the differences between rural and urban populations.