|Dr David Scott|
A world-first study led by researchers at the School of Clinical Sciences at Monash Health sheds light on the health effects of vitamin D and high physical activity levels among older adults.
Published in The Journal of Clinical Endocrinology and Metabolism, the research is the first to show that having both high vitamin D and high physical activity levels reduces gains in body fat over five years in older adults.
However the reduction in weight gain is probably not explained by a direct benefit of vitamin D alone, said lead author Dr David Scott from the Department of Medicine.
“Rather, the finding appears to be related to the fact that older adults with high vitamin D and physical activity levels perform more moderate and vigorous intensity activity,” said Dr Scott.
“While both high vitamin D and high physical activity levels have been linked to lower body fat and better muscle strength during ageing, it is not clear whether these effects are independent of each other, or whether high vitamin D enhances physical activity benefits in older adults.”
The research team measured vitamin D levels and physical activity (steps per day) in 615 community-dwelling older adults.
“Five years later, we examined the study participants’ muscle strength and changes in their body composition using specialised X-rays.”
“We found that those with both high vitamin D and physical activity levels had significantly smaller increases in body fat compared to those with either low vitamin D or low physical activity.”
However, and most significantly, the study reveals that higher levels of moderate and vigorous physical activity may account for the observed health benefits of high vitamin D in older adults.
“In a group of study participants whose physical activity was also measured by accelerometers (capable of measuring intensity of physical activity as opposed to total activity amount only), more vigorous and intense physical activity explained the apparent additional benefits of high vitamin D levels.”
There were no consistent findings for effects of vitamin D and physical activity status on muscle strength.
“While further research is required to confirm our results, they support the concept that older adults should be encouraged to participate in physical activity at higher levels of intensity, such as brisk walking, jogging, swimming and resistance training,” added Dr Scott.