Understanding the impact of vitamin D supplement formulation, quality and provision to older adults in UK residential care homes.

Supplying vitamin D supplements to all older adults is beneficial and cost-effective. However, operationalising this supply to residents in long-term care is problematic. This study aimed to understand the challenges of vitamin D supplement provision by auditing the extent of supplementation, measuring the quality of the supplements and investigating the attitudes towards supplement provision in UK care homes. This case study investigated the supply of vitamin D supplement formulations in four UK care homes and analysed the vitamin D content of nine formulation types. It employed semi-structured interviews with care home stakeholders to understand attitudes toward vitamin D supply. Across the nine analysed products, there was >50% variability in their quality (75-137% of the label), but 44% of supplements were of medicinal grade. One tablet from a food-grade product contained 167% vitamin D, and one medicinal-grade tablet only contained 70% vitamin D. Interviews with care home staff highlighted four challenges to providing supplements: the perceived responsibility of healthcare professionals to supplement, difficulties obtaining prescription medications, the absence of national/local strategies, and the financial burden. This study demonstrated sub-optimal vitamin D supplement supply to care home residents, with staff unclear about who was responsible for choosing the correct type of vitamin D supplement, who paid for it, and who was to supply it. This study suggests a new approach to delivering vitamin D supplements to older adults is needed.