Improving Vitamin D Status in Home-bound Elders (MOW VitD)

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. A secondary goal is to obtain preliminary data on the effectiveness of vitamin D supplementation on improving vitamin D levels and reducing falls.

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.

Determine the effectiveness of the intervention on improving 25-hydroxyvitamin D levels (change in 25(OH)D from baseline to 5-month follow-up). Measured as 5-month follow-up 25(OH)D level minus baseline 25(OH)D level.

Determine the effectiveness of the intervention on reducing the number of falls using monthly fall calendars (compare the average number of falls in vitamin D3 group vs. active placebo group over 5 months)

Number of participants who consumed at least 4 out of a possible 5 supplement doses (=>80% compliance) over 5 months.

Inclusion Criteria: Age ≥ 65 years old Forsyth County Senior Services Meals-on-Wheels recipient Willing to provide informed consent Willing to be randomized to vitamin D or active placebo control Exclusion Criteria: Hyperparathyroidism Kidney stones (within the past 2 years) History of hypercalcemia On dialysis Inability or contraindications to consume vitamin D supplements Taking prescription vitamin D2 or vitamin D3-containing supplements totaling > 1000 IU/d Planning to move within the next 6 months