Association Between Serum Vitamin D Levels, Skin Color and Estimated Sunlight Exposure Time in Young Adults Residing in Yangon Region

Background and Aim: People living in Myanmar are exposed to adequate sunlight throughout the year. Therefore, residents of Yangon, one of Myanmar's cities, are assumed to have sufficient vitamin D levels from sunlight. While many studies suggested that individuals with fair skin tend to produce more vitamin D than those with darker skin, some studies found lower vitamin D levels in fair-skinned individuals compared to their darker-skinned counterparts. Since young adults are more likely to engage in outdoor activities, they are expected to have more sunlight exposure and higher vitamin D levels. This raises an interesting question whether young adults of different skin colors exhibit varying serum vitamin D levels. Thus, the present study aimed to find out vitamin D status and its association with skin color and estimated sunlight exposure time in young adults. Materials and Methods: This study was carried out in 143 young adults aged 21-39 years. Serum vitamin D level was measured by enzyme-linked immunosorbent assay method and skin color by skin tone analyzer. Sunlight exposure time was estimated by questionnaires. Results: Among 143 subjects, 67.8% were vitamin D sufficient (≥32 ng/mL), 28.7% were vitamin D insufficient (20-31 ng/mL) and 3.5% were deficient (<20 ng/mL). Gender difference in serum 25(OH)D level was observed (p<0.001). Statistically significant association was observed between vitamin D status and estimated sunlight exposure time groups (p<0.001) and skin color groups (p<0.05). Conclusion: It can be assumed that both estimated sunlight exposure time and skin color are contributing factors for determining serum vitamin D levels.