Heald, A. H., Anderson, S. G., Scargill, J. J., Short, A., Holland, D., Khan, A., …Livingston, M. (2017). Social Disadvantage Is Associated With Lower Vitamin D Levels in Older People and There Is No Surrogate for Its Measurement. Gerontology and Geriatric Medicine, https://doi.org/10.1177/2333721417697843