Older people are at increased risk of inadequate vitamin D production in the skin because of reduced sun exposure and the reduced ability of the skin to synthesize vitamin D.
Although Australia is a sunny country, our previous survey with 558 women aged 70 to 90 years showed that 61% of them were vitamin D deficient or insufficient (serum 25-hydroxyvitamin D concentration < 60 nmol/L).
Low vitamin D status may have negative effects on the maintenance of bone and muscle health. However, there have been limited long-term longitudinal data on the role of vitamin D status on the risks of musculoskeletal diseases in older women. Also, few studies evaluated the prevalence and contributing factors of vitamin D insufficiency in community-dwelling older Australian women.
We have been following a cohort of 1500 older women since 1998. Blood samples have been collected at baseline and year 5 and 7 and are being collected at year 10 and stored at -80ºC. In this cohort, adverse events data (including any falls and fractures and/or death, change in state or severity of chronic pre-existing or present disease, and new diagnosis of a condition not previously known), medication use, bone structure and density, muscle strength, physical performance, lifestyle and demographic data have been collected in the past 10 years.
We have a world-class track record in the field of nutrition and musculoskeletal health. In this application, we aim to expand our research interest on vitamin D and examine the association between vitamin D status and bone structure and fracture risk, physical performance and risk of falling, and the prevalence of vitamin D insufficiency and it contributing factors in this cohort of older women.