A Cross-sectional Study on the Vitamin D Status in a Group of Indoor and Outdoor Workers in Galle, Sri Lanka

Background: Vitamin D deficiency influences various disease conditions; thus, it is important to evaluate the social groups for vitamin D deficiency to reduce the risk. Occupation-related factors are believed to be contributing to vitamin D deficiency.

Objectives: To assess the vitamin D status of indoor and outdoor workers, the effect of sunlight exposure, and other work-related factors on vitamin D status.

Method: This cross-sectional study measured the 25 hydroxy Vitamin D (25(OH) Vit D) levels using chemiluminescence immunoassay in male workers (n=96) working indoors and outdoors in Galle, Sri Lanka. Data on sunlight exposure and other factors were collected by using an interviewer-administered questionnaire and statistically analyzed using SPSS software version 20.0.

Results: The mean±SD 25(OH) Vit D level of outdoor and indoor workers were 17.94±3.85 ng/mL and 16.79±4.52 ng/mL, respectively (p=0.185). The prevalence of vitamin D deficiency (< 20ng/mL) of the sample was 73%, and 27% of the participants were vitamin D insufficient (21 -30ng/mL). There was a positive correlation of 25(OH) Vit D level with the duration of sun exposure (r=0.153, p=0.136). Significantly different 25(OH) Vit D levels were found with educational level, monthly income, and clothing pattern (p < 0.05).

Conclusions: There was no significant difference between the vitamin D levels of indoor and outdoor workers. The results of this study revealed that vitamin D deficiency was highly prevalent among workers in Sri Lanka. As the reference ranges of vitamin D status for the Sri Lankan population is not well stated, further studies are needed to confirm the same.