Serum 25-Hydroxyvitamin D Status and Associated Factors in Premenopausal Working Women

Lim, Hwa Jae

Abstract

This study was performed to estimate serum 25-hydroxyvitamin D level and to evaluate the relationship between serum 25-hydroxyvitamin D level and associated factors. The subjects were 61 premenopausal working women aged 30 - 49 y in Busan. The serum 25-hydroxyvitamin D level was measured by radioimmunoassay. Data for physiological characteristics, lifestyle factors, physical activity and nutrient intake were assessed by questionnaire including information about outdoor activity time, daily activity diary and 24 hr recall method. The mean vitamin D intake was 3.12 ug, which corresponded to 62.5% of the Korean RDA. The mean level of serum 25-hydroxyvitamin D was 31.0 ng/mL. Low 25-hydroxyvitamin D (<25 nmol/L) was not found in the subjects. The serum 25-hydroxyvitamin D level showed positive significant correlations with exercise hours, daily energy expenditure, hours of outdoor activity per weekdays (p< 0.001, p< 0.05, p< 0.05). Exercise hours were found to be the most important determinant of serum 25-hydroxyvitamin D level. Therefore nutritional education for increasing hours of physical activity including indoor and outdoor exercise, is needed for premenopausal working women to increase vitamin D status.