Optimizing Vitamin D in the Elderly

Vitamin D deficiency is highly prevalent in older people in the absence of vitamin D supplementation. The limited data available show marked inter-individual variability in response to vitamin D supplementation in very old, frail elderly with almost 25% remaining vitamin D deficient (25-OH D \< 20 ng/mL) when receiving the currently recommended 800 IU/day vitamin D. This proposal is for exploratory research on the use of a wide range of oral vitamin D3 doses in frail elderly living in controlled living environments.