A Cross Section Study of Vitamin D levels in Thai Office Workers

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Sant Chaiyodsilp, MD
Tanavee Pureekul, RN
Yuphin Srisuk
Cholpatsorn Euathanikkanon


To determine the current level of serum vitamin D of adult Thai office workers in 2014 by using a standard laboratory method and its level in relation to sex, age, sunlight exposure and dressing.
MATERIALS AND METHODS: This is a cross section study of 211 Thai office and field workers of one company performed in April 2014. The study used an electrochemiluminescence (or electrogenerated chemiluminescence (ECL)) method to determine their blood level of 25(OH)D. Their level of 25(OH)D then was analyzed against their age, sex, sunlight exposure time, and choice of clothing, using pearson coefficient.
Two hundred and eleven office workers aged between 23 and 63 years old were included in this study. Eighty one of these were male and 124 were female. Of these, 72.5% are aged between 31 and 50 years old. Ten percent of them are underweight, while 27.2% of them are overweight (BMI > 25 kg/m2). One hundred and thirty four of them (63.5%) had vitamin D level > 20 ng/ml considered normal by Thai normal value rates. Seventy seven of them (36.5%) had vitamin D levels less than 20 ng/ml or had hypovitaminosis D by Thai normal value rates. There is no significant relation between vitamin D levels and age, sex, sunlight exposure time, and choice of clothing.
About a third (36.5%) of these Thai office workers were deemed to have hypovitaminosis D when measured against the standard normal value of 20 ng/ml upwards. The level of vitamin D from this study is much lower than previously estimated and will change the health promotion and disease prevention methodology for diseases related to hypovitaminosis-D in the future.


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Chaiyodsilp S, Pureekul T, Srisuk Y, Euathanikkanon C. A Cross Section Study of Vitamin D levels in Thai Office Workers. BKK Med J [Internet]. 2015 Feb. 20 [cited 2023 Dec. 6];9(1):8. Available from: https://he02.tci-thaijo.org/index.php/bkkmedj/article/view/220593
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