Improving Vitamin D Status in Home-bound Elders: a Pilot Study

In the past two decades, the role of vitamin D has extended beyond bone health to encompass a wide range of biological activities important to physical function in older adults. A growing body of evidence now shows that circulating 25-hydroxyvitamin D (25(OH)D) levels < 75 nmol/L (< 30 ng/mL)) are associated with physical impairments such as reduced walking speed and impaired balance as well as falls. Older adults are at risk for low levels of 25-hydroxyvitamin D because of reduced exposure to ultraviolet B radiation, reduced efficiency of previtamin D synthesis in the skin, and low dietary intake. Although data from the National Health and Nutrition Examination Survey (NHANES) 2000-2004 indicate that frank vitamin D deficiency (serum 25(OH)D < 25 nmol/L [10 ng/mL]) is rare in the U.S. (5% or less), vitamin D insufficiency (serum 25(OH)D < 75 nmol/L [30 ng/mL]) is prevalent (~75%) among older adults. Older home-bound adults are a vulnerable subgroup of older adults for poor dietary intake and nutritional health, nutrition-related health conditions, and functional decline and disability. The primary goal of this pilot study is to assess the feasibility of a partnership with Senior Services of Forsyth County to address vitamin D insufficiency in home-bound older adults receiving home-delivered meals. The investigators will accomplish this goal by conducting a 5-month randomized, controlled trial in 200 older Meals-on-Wheels (MOW) recipients randomized to receive monthly either (1) 100,000 IU vitamin D3 or (2) an active placebo (vitamin E) to achieve the following specific aims:

Aim 1: Determine the prevalence of falls and risk of vitamin D insufficiency in 200 MOW recipients.

Aim 2: Assess the feasibility of the vitamin D intervention delivered through the MOW program.

Aim 3: Obtain preliminary data on the effectiveness of the intervention on improving vitamin D status and reducing falls.

Data from this pilot study will: 1) provide estimates of the prevalence of falls and vitamin D insufficiency in home-bound older adults participating in the Forsyth County MOW program; 2) provide estimates of participant compliance and drop-out to a vitamin supplementation trial delivered as part of the MOW program; 3) provide evidence for the efficacy of the vitamin D dose proposed in remediating vitamin D insufficiency; and 4) provide preliminary data on the potential benefit of vitamin D supplementation on falls in a home-bound older population.