Are avoiding sunlight exposure and low physical activity resulting micro evolution in tropical country women?

Background: Previous studies have shown that low 25(OH)D serum levels may increase mortality and morbidity, especially in women. Low levels often occur during the winter and spring of temperate countries due to low sun exposure but there are many other factors linked with vitamin D deficiency that can occur in tropical countries. Objectives: To assess 25(OH)D serum levels in Indonesian women and determine factors that can influence these levels. Method: This cross-sectional study was conducted on 156 healthy Indonesian women during the dry season. This study measured serum 25(OH)D levels, examined two single nucleotide polymorphisms in the vitamin D receptor (TaqI and BsmI), and assessed environmental, lifestyle and physiological factors including occupation, sun exposure, vitamin D intake, and body fat percentage. Results: The mean serum 25(OH)D level was 18.8 ± 7.0 ng/mL.There were 148 subjects categorized as either deficient and insufficient, and eight were categorized as sufficient. However, none of the subjects achieved normal 25(OH)D values (normal value in sunny countries: 54-90 ng/mL) and there was no significant difference in serum 25(OH)D levels between obese (OG) and non-obese groups (NG). All participants were heterozygous (T>C for TaqI and A>G for BsmI). All subjects were found to have low levels of sun exposure, a high percentage of body fat, and a low intake of vitamin D. There were associations between vitamin D deficiency-insufficiency and sufficiency with indoors occupation (p=0.001), less than 1 hour sun ray exposure (p=0.007), moderate physical activity (p=0.014, OR: 6.25, CI95% 1.26-32.12), low vitamin D intake (p=0.012, OR: 5.435, CI95% 1.268-23.29), and high body fat percentage (p=0.003, OR: 14.14, CI95% 1.69-118.19). Conclusion: The results showed that vitamin D deficiency may occur in women with lower body fat percentage and also with high amount of body fat. All participants were heterozygous (T>C for TaqI and A>G for BsmI)TheTaqI and BsmI polymorphisms were present in all women studied. Factors that most influenced vitamin D serum were physical activity, vitamin D intake, and body fat percentage. IndexTerms—vitamin D, polymorphism, lifestyle, body fat,