Association between vitamin D intake and bone mineral density in Koreans aged ≥ 50 years: analysis of the 2009 Korea National Health and Nutrition Examination Survey using a newly established vitamin D database

BACKGROUND/OBJECTIVES: Vitamin D plays an important role in skeletal growth and maintenance and in the prevention of various diseases. We investigated the relationship between vitamin D intake and bone mineral density (BMD) in Korean adults aged ≥ 50 years using the 2009 Korea National Health and Nutrition Examination Survey data. SUBJECTS/METHODS: This study was conducted in 1,808 subjects aged ≥ 50 years with BMD data in Korea. Dietary vitamin D levels were assessed by the 24-hour recall method. BMD was measured using dual-energy X-ray absorptiometry. We investigated general characteristics and the association between these characteristics, vitamin D status, and BMD. RESULTS: Vitamin D intake was significantly lower in the osteoporosis group among women (P 2.51 µg/day (average intake of women) was higher than that of women with a vitamin D intake ≤ 2.51 µg/day (P < 0.001). CONCLUSIONS: Korean adults should increase their BMD by increasing serum 25(OH)D concentration. Furthermore, increasing vitamin D intake could improve BMD, especially in Korean women who consume less calcium than the estimated average requirement.

Maternal vitamin D intake and serum 25-hydroxyvitamin D (25(OH)D) levels associated with blood pressure: A crosssectional study in Padang, West Sumatra

@#Introduction: The association between vitamin D inadequacy and blood pressure (BP) has been studied in several populations. We examined the association of maternal vitamin D intake and serum 25(OH)D levels and BP among pregnant women in West Sumatra. Methods: This study was conducted using a comparative cross-sectional study in a maternal clinic selected by convenience in Padang. Pregnant mothers who attended the clinic in July-August 2015 were recruited. Inclusion criteria were pregnancy between 28-42 weeks, aged 20-35 years, and with less than three parity status. A total of 56 women were recruited and divided equally into either normotension or hypertension groups. Subjects with blood pressure less than 120 mmHg (SBP) and 80 mmHg (DBP) were placed in the normotension group, while subjects with ≥140 mmHg (SBP) and/or ≥90 mmHg) were in the hypertension group. Subjects completed a pre-tested semi-quantitative food frequency questionnaire. Three ml of non-fasting blood was drawn from each subject for determination of 25(OH)D, urea, creatinine, leukocyte, and blood glucose levels. Results: There was a significant difference in mean serum 25(OH)D, between the normotension and hypertension groups, at 36.85±21.58 pg/ml and 17.36±7.91 pg/ml, respectively. Only 20% of participants from the hypertension group had adequate vitamin D intake. Blood pressure status had a significant association with vitamin D intake status (p=0.001). Conclusion: Maternal vitamin D intake and 25(OH)D levels were associated with blood pressure status in this sample population. Further studies with a larger sample population are suggested to verify the findings of this study.

Vitamin D intake, Outdoor Activity Time and Serum 25-OH Vitamin D Concentrations of Korean Postmenopausal Women by Season and by Age / 대한지역사회영양학회지

OBJECTIVES: The purpose of this study was to examine the relative impact of seasonal differences and age on dietary vitamin D intakes, outdoor activity time and serum vitamin D status among Korean postmenopausal women. METHODS: A cross-sectional study was conducted with 164 free-living postmenopausal women (mean age=55.4 years) in Daegu, Korea. Dietary intake, daily physical activity patterns and fasting blood samples were collected during summer and winter. We compared the results from 75 women during summer and 89 women during winter. Dietary intake of vitamin D was assessed by 24-hour recall method. Daily outdoor activity time was derived from physical activity diary. RESULTS: The average dietary intake of vitamin D of the participants was 3.7 microg during summer, 3.3 microg during winter, showing no significant difference between the two seasons. The average time spent on outdoor activities was not significantly different between summer (=35.1 +/- 75.0 min/d) and winter (=48.5 +/- 76.8 min/d). The average serum 25-(OH) vitamin D concentrations of participants was 17.5 +/- 7.5 ng/mL in the summer and 13.4 +/- 4.3 ng/mL in the winter, showing no significant differences by season. Dietary intake of vitamin D was not related to age. When total subjects were divided into two groups by age, the average serum 25-(OH) vitamin D concentration was significantly higher in older group (p=0.047) and time spent on outdoor activities was also (p=0.018) significantly higher in the older group. CONCLUSIONS: In order to improve the current vitamin D status of Korean postmenopausal women, nutrition education programs should focus more on adequate intake of vitamin D, while maintaining enough outdoor activities over the season.

Skin Color and Self-reported Sun Exposure Scores are Associated with Serum 25-Hydroxyvitamin D Concentrations in a Multi-ethnic Population Living in South Florida.

Aims: The aim was to investigate the association between serum 25-hydroxyvitamin D [25(OH)D], skin color and sun exposure score. Study Design: Cross-sectional. Place and Duration of Study: Florida International University, Robert Stempel College of Public Health and Social Work, Department of Dietetics and Nutrition, Miami, Florida from July 2012 to October 2012. Methodology: Seventy six adults, ages 18-36 years living in South Florida participated in the study. Skin color was quantified by a IMS Smart Probe 400 scanner and 25(OH)D was measured by ELISA. A sun exposure questionnaire was used to record the weekly sun exposure scores. A food frequency questionnaire was used to record daily vitamin D intake. Results: Multiple-linear regression analysis indicated that sun exposure, forearm skin color and vitamin D intake were significant predictors of 25(OH)D (P=.004, P=.003 and P=.021 respectively). This association held after controlling for covariates (B=.371, P=.027 for forearm, B=.031, P=.005 for total sun exposure and B=.689, P=.003 for vitamin D intake). Conclusion: Skin color, sun exposure along with vitamin D intake may be used as an indirect non-invasive tools to estimate 25(OH)D levels in healthy individuals in South Florida.

Seasonal Differences in Outdoor Activity Time and Serum 25-(OH) Vitamin D Status of Korean Young Women / 대한지역사회영양학회지

OBJECTIVES: This study was intended to examine the seasonal differences in outdoor activity times and dietary vitamin D intakes, and explicates their relative impact on improving serum 25-(OH) vitamin D status among Korean young women. METHODS: A cross-sectional study was conducted with 135 free-living women aged 19-39 years in Daegu-Kyungbook, Korea. We compared the results from 52 women for the summer and 83 women for the winter. Dietary intake of vitamin D was assessed by 24 hour recall method for non-consecutive three days as well as by food frequency method. Daily outdoor activity times were derived from 24 hour physical activity diary. RESULTS: The average dietary intake of vitamin D of the participants by 24 hour recall method was 3.1 microg during the summer, 3.3 microg during the winter, showing no significant difference between the two seasons. Times spent on outdoor activities (p < 0.01) in the summer (= 23.8 +/- 23.6 min) were much longer than that in the winter (= 10.8 +/- 13.4 min). The serum 25-(OH) vitamin D levels of participants were 17.5 +/- 7.5 ng/mL in the summer and 13.4 +/- 4.3 ng/mL in the winter, showing that the latter was significantly lower than that of the former (p < 0.001). The serum 25-(OH) vitamin D levels of subjects were positively related to outdoor activities (r = 0.315, p < 0.05) during the summer, while related to dietary intake (r = 0.252, p < 0.05) during the winter. CONCLUSIONS: In order to improve the current vitamin D status of Korean young women, nutrition education programs should focus on increasing more dietary intake especially during the winter, and performing more outdoor activities in other seasons.

Vitamin D Intake and Sun Exposure Among Malaysian Athletes in National Sports Institute, Bukit Jalil

Introduction: Vitamin D plays an important role in maintaining the physical health as well as the performance of athletes. This cross-sectional analytical study was conducted to determine vitamin D intake, sun exposure and skin types of both indoor and outdoor Malaysian athletes in the National Sports Institute, Bukit Jalil. Method: A total of 28 indoor (badminton, shooting, wushu and fencing) and 36 outdoor (athletics, football and hockey) athletes were recruited for this study. The dietary vitamin D intake was estimated using Vitamin D-specific Food Frequency Questionnaire (FFQ). The Sun Exposure Index (SEI) was calculated from Seven-day Sun Exposure Record while the skin types of athletes were determined using Fitzpatrick Skin Typing Questionnaire. Results: The mean age of the athletes was 21.02±4.11 years and their mean Body Mass Index (BMI) was 22.20±2.22 kg/m2. The mean body fat percentage of outdoor athletes was significantly lower than indoor athletes (p<0.001). Forty two athletes (65.6%) met the recommended nutrient intake (RNI) value for vitamin D and the outdoor athletes had significantly greater amount of vitamin D intake compared to RNI (p<0.05) and the indoor athletes (p<0.05). The indoor athletes spent significantly less time outdoor per day (p<0.05) and had lower SEI per day (p<0.05) than outdoor athletes. Most of the indoor athletes (53.6%) had type II of Fitzpatrick skin type while the outdoor athletes (47.2%) had type III of Fitzpatrick skin type. Conclusion: The outdoor athletes had higher intake of vitamin D and more sun exposure than indoor athletes. There is a need to ensure the adequacy intake of vitamin D among indoor athletes.

Análisis nutricional en el aporte del mineral calcio en mujeres con lactancia / Calcium intake nutritional status in breastfeeding women

El objeto del presente estudio fue analizar las dietas de 39 mujeres (edad media = 34.3 años; IMC medio = 26.2 kg/m²) sanas y con lactancia exclusiva, mediante Encuesta Dietética de Recordatorio de 24 horas y utilizando el software Dial®, centrándonos en el aporte diario de calcio y vitamina D. La población a estudio se agrupó en función de si su ingesta en calcio era mayor (no restrictivas) o menor (restrictivas) a la Ingesta de Referencia para la Población según la Unión Europea. Los resultados obtenidos revelaron inicialmente que en un 64 por ciento de dicha población (restrictivas) el aporte energético seguía una tendencia deficitaria, siendo de 2042.7 ± 458.3 kcal. Además su ingesta de calcio (812.4 ± 211.2 mg/día) fue inferior (p<0.01) a la recomendada, así como la ingesta en vitamina D, en donde su aporte diario también fue deficitario (1.71 ± 1.59 µg/día) respecto al resto de la población (no restrictivas). Tras estos resultados, se puede concluir que un alto porcentaje de estas madres se encuentra por debajo de las recomendaciones nutricionales durante su etapa de lactancia, siendo aconsejable que fueran informadas por los profesionales sanitarios sobre los hábitos alimentarios requeridos en este periodo.

The aim of this study was to analyze the diets of 39 healthy, lactating women (average age = 34.3 years; average BMI = 26.2 kg/m²) by a 24-hour dietary recall. This investigation was focused on calcium and vitamin D intake. Nutrients were estimated using the software Dial®. These participants were divided into calcium restrictors, defined as calcium intake <1200 mg/day, and non-restrictors (>1200 mg/day). The results showed that 64 percent of the study population (restrictors) reported a mean energy intake (2042.7 ± 458.3 kcal), calcium intake (812.4 ± 211.2 mg/day) and vitamin D intake (1.71 ± 1.59 µg/day) below the adequate intake level (AI) and lower than non-restrictors estimated intakes (p<0.01). The conclusion of this study is that a high percentage of the lactating women consume a diet below nutritional recommendations during this stage. It is recommended that health professionals should inform these mothers about the correct dietary habits during this period.

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.