COVID-19, study status being reviewed on an ongoing basis.

Vitamin D deficiency is proposed to be prevalent in community-dwelling older adults, with prevalence substantially higher among older adults in residential care facilities. Musculoskeletal health is compromised in older vitamin D deficient individuals and alongside frailty, sarcopenia and osteoporosis associated with ageing, affected individuals are at increased risk of falls and fractures. Vitamin D supplementation is an effective intervention for fall prevention and, along with calcium supplementation, in fracture risk reduction in institutionalised older adults. Thus, monitoring vitamin D status and treating deficiency among older adults in residential care facilities may limit the substantial economic burden associated with falls/fractures in this population. The vitamin D status of older adults in residential care facilities in Northern Ireland (NI) is currently unknown, therefore, the aim of this pilot study is to determine the vitamin D status of this cohort of the population, and to define factors which may influence vitamin D status, including body mass index (BMI), mobility out-of-doors, medication use, dementia and diet. Vitamin D status will be determined via the measurement of 25-hydroxyvitamin D using liquid chromatography-tandem mass spectrometry (LC-MS/MS). In addition, biomarkers associated with vitamin D metabolism will be measured including calcium, albumin, creatinine, urea, bone turnover markers and parathyroid hormone. Factors that may affect vitamin D status will be assessed using a health and lifestyle questionnaire and dietary vitamin D intake will be estimated via analysis of the menus in the residential care facilities. Vitamin D supplementation practices in these facilities will also be assessed via analysis of drug prescription records, focusing on differences between residents who have/have not suffered a fracture. Physical measures such grip strength, timed up and go test and T-score measurement via Achilles ultrasound machine will be taken. This study will provide data on the prevalence of vitamin D deficiency in older adults in residential care facilities within NI and identify factors that predispose residents to increased risk of deficiency. Dissemination of these findings, along with analysis of current supplementation practices, will help practitioners to develop a strategy to identify those residents with vitamin D deficiency/insufficiency and thus requiring supplementation ultimately improving health and well-being. This study will also inform the design of a larger study to investigate vitamin D status, supplementation and musculoskeletal health in older adults in residential care facilities within Northern Ireland, providing important information that will ultimately contribute towards reducing falls and fractures within this population.

Inclusion Criteria:

• Currently residing (≥1 month) within a residential care facility in the Western Health and Social Care Trust in Northern Ireland

Exclusion Criteria:

• Participants will be excluded from the study if by the judgement of the consultant rheumatologist that they have very abnormal bone or vitamin D metabolism due to conditions such as end stage renal failure or bone metastases.

Older adults within residential care facilities in the Western Health and Social Care Trust in Northern Ireland have been selected to be studied. Residents are being investigated to determine vitamin D status and bone.