Functional Improvement with Vitamin D Replenishment in a Cohort of Frail, Vitamin D-deficient Older People

Objective: To evaluate functional improvement in a population of frail, homebound older persons with low vitamin D status as vitamin D stores improve.

Design: Randomized, controlled intervention study.

Setting: Subjects' homes and a nursing facility in Baltimore, Maryland.

Participants: The first 32 subjects (community-dwelling, homebound older subjects from the Johns Hopkins Elder Housecall Program and nursing home residents from the Johns Hopkins Geriatrics Center) entered in a longitudinal study of vitamin D replacement.

Measurements: Baseline 25-hydroxyvitamin D levels were measured and repeated at least 1 month after therapy with either placebo or vitamin D (ergocalciferol). Subjects were also administered the Frail Elderly Functional Assessment (FEFA) questionnaire, an instrument demonstrated to be reliable, valid, and sensitive to small increments of functional change in this population.

Main Results: All subjects started with 25-hydroxyvitamin D levels less than 15 ng/mL. Those subjects whose levels improved by at least 3 ng/mL (> assay coefficient of variation) also demonstrated improvement in FEFA score. Regression analysis between change in FEFA score compared with change in 25-hydroxyvitamin D was significant (r = .4; P = .02).

Conclusions: In this cohort of homebound older people, improvement in vitamin D status was associated with functional improvement as measured by the FEFA questionnaire.