Association between leisure-time aerobic physical activity and vitamin D concentrations among US older adults: the NHANES 2007-2012.

BACKGROUND: Although previous studies have described a positive correlation between physical activity and 25-hydroxyvitamin D concentrations (25(OH)D), there have been inconsistent results in regard to the frequency or intensity of physical activity needed to achieve adequate 25(OH)D status.

AIMS: To examine the relationship between self-reported leisure-time physical activity and 25(OH)D3 and 25(OHD) concentrations among US adults aged 60 years and older.

METHODS: The present analysis was based on data from participants in the National Health and Nutrition Examination Survey 2007-2012. Moderate or vigorous leisure-time physical activity was calculated by min/week or metabolic equivalent task scores-minutes/week and defined according to the 2008 Physical Activity Guidelines for Americans. General linear models adjusted for confounders were created to compare mean 25(OH)D and 25(OH)3 concentrations across physical activity status.

RESULTS: A total of 4764 adults with a mean age of 69.7 years comprised the study sample. Overall, 33.3% men and 23.1% women were defined as physically active and participants' mean 25(OH)D and 25(OH)D3 concentration was 75.0 and 68.8 nmol/L, respectively. Older adults physically active had 8.1 and 7.1 nmol/L higher 25(OH)D and 25(OH)3 levels than those physically inactive, respectively. Moreover, higher 25(OH)D3 and 25(OH)D concentrations were consistently seen during the summer and autumn months. In contrast, sedentary older adults had on average 25(OH)D levels < 75 nmol/L irrespective of the 6-month study period examined.

CONCLUSIONS: Leisure-time physical activity appears to be an effective manner of maintaining adequate vitamin D concentrations later in life. Therefore, promoting physical activity in older adults should be a national public health priority.