Association between Blood Vitamin D Levels and Regular Physical Activity in Korean Adolescents

Physical activity, Vitamin D, and all-cause/cardiovascular mortality: a prospective study in older Chinese adults

BACKGROUND

Physical activity was associated with the risk of all-cause and cardiovascular mortality. However, little is known about older adults, especially those aged over 80 years.

METHODS

2863 older adults in the Chinese Longitudinal Healthy Longevity Survey (CLHLS) were enrolled. Physical activity score was used to evaluate the physical activity. Serum 25-hydroxyvitamin D and demographic characteristics were collected at baseline. We used multivariable-adjusted Cox regression models and stratified analysis to determine the association between physical activity, vitamin D and all-cause/cardiovascular mortality. Mediation analysis was performed to evaluate the mediating effect of vitamin D between physical activity and all-cause/cardiovascular mortality.

RESULTS

The median age of this population was 87 years, and 70.27% were the oldest-old (age ≥ 80 years). We observed a tendency for a higher vitamin D concentration in participants with higher physical activity score levels. Both physical activity and vitamin D levels were inversely associated with all-cause and cardiovascular mortality in all participants. Between physical activity and all-cause/cardiovascular mortality, the mediation proportions of vitamin D were 7.76% (P < 0.001) and 4.13% (P < 0.001), respectively. The mediating effect of vitamin D remained all significant in various types of physical activities. Furthermore, vitamin D accounted for a greater mediating proportion in the physical activities of housework and raising domestic animals/pets.

CONCLUSIONS

Physical activity could reduce the risk of all-cause/cardiovascular mortality and was mediated by vitamin D in older Chinese adults.

The relationship between physical activity levels and serum vitamin D levels varies among children and adolescents in different age groups

Objective

The objective of the present study was to explore the relationship between physical activity (PA) levels and serum vitamin D levels in children and adolescents of different ages and sexes.

Methods

All the data in this study were collected during two cycles (2011-2014) of the National Health and Nutrition Examination Survey (NHANES). Our study participants were aged ≥3 and < 20 years and had valid data for all variables, including vitamin D intake, serum vitamin D levels, PA volume and intensity levels, amount of time spent outdoors, body mass index (BMI), sex, and race.

Results

A total of 3,312 participants were included in the study; 1,672 were boys (50.4%), and 1,640 were girls (49.6%). A total of 250 (7.5%) children were aged 3-5 years, 1,474 (44.5%) were aged 6-11 years, and 1,588 (47.9%) were aged 12-19 years. Both PA volume and intensity were positively related to serum vitamin D levels in the 6-11-year-old boys and girls (p < 0.05 for both) and in the 12-19-year-old boys. No significant relationship between PA volume or intensity and serum vitamin D levels was detected in the 3-5-year-old group or in the 12-19-year-old girl group. The time spent outdoors and the BMI of the participants had mediating effects on the relationships of PA volume and intensity with serum vitamin D levels in boys and girls aged 6-11 years.

Conclusion

The relationship between PA and vitamin D varies among children and adolescents of different sexes and ages, and the sun exposure level and BMI had mediating effects on the relationship between PA and the serum vitamin D level. The mechanism of the relationship between PA and increased serum vitamin D levels needs further in-depth research.

High Incidence of Vitamin D Deficiency (VDD) Among Indoor Workers: Association with Dietary and Lifestyle Factors

The study evaluated the relationship of various dietary and lifestyle factors with vitamin D status and bone health of adults engaged in office jobs. A total of 100 subjects comprising of 50 males and 50 females (with their willingness to participate) in the age group of 30-50 years were purposively selected for the investigation, who were spending 8 hours in the offices. Results showed that most of the subjects had vitamin D deficit with mean serum vitamin D level as 13.2 ng/ml and 68% were osteopenic. Dietary phytates, sedentary lifestyle, higher body mass index were found to have a deleterious impact on vitamin D status. This silent epidemic needs to be addressed with effective public health initiatives, such as raising awareness about the availability of fortified foods, optimum time, and body surface area for sun exposure.