Serum 25-Hydroxyvitamin D Status in Wintertime in Premenopausal Working Women

This study was performed to estimate serum 25-hydroxyvitamin D (25-OHD) level in wintertime and to evaluate the relationship between serum 25-OHD level and associated factors in 50 premenopausal working women aged 30 . 49 y in Busan. The serum 25-OHD level was measured by radioimmunoassay. Data for physiological characteristics, lifestyle factors, physical activity and nutrient intake was assessed by questionnaire including information about outdoor activity time, daily activity diary and 24hr recall method. The mean vitamin D intake was 4.24 ug, which corresponded to 84.9% of the Korean RDA. The mean level of serum 25-OHD was 25.7 ng/mL. Vitamin D deficiency (25-OHD or = 75 nmol/L) were not found in the subjects. However, the prevalence of vitamin D insufficiency (25-OHD < 15 nmol/L) and hypovitaminosis D (25-OHD < 30 nmol/L) were 12% and 60% respectively. The serum 25-OHD level showed positive significant correlations with the duration of outdoor activity per weekdays (p < 0.05). Our findings suggest that hypovitaminosis D was common in the subjects in wintertime. So nutritional education for increasing outdoor activities is needed for premenopausal working women to increase vitamin D status in wintertime.

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

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.