Delivery of a Vitamin D Intervention in Homebound Older Adults Using a Meals-on-Wheels Program: A Pilot Study

OBJECTIVES: To assess the feasibility of a vitamin D intervention delivered through a Meals-on-Wheels (MOW) program to improve 25-hydroxyvitamin D (25(OH) D) concentrations and reduce falls in homebound older adults. DESIGN: Single-blind, cluster randomized trial. SETTING: MOW, Forsyth County, North Carolina. PARTICIPANTS: Community-dwelling homebound adults aged 65 to 102 (N = 68). INTERVENTION: MOW clients were randomized to vitamin D-3 (100,000 IU/month; n = 38) or active placebo (400 IU vitamin E/month; n = 30) according to MOW delivery route. MEASUREMENTS: Serum 25(OH) D was assessed at baseline and 5-month follow-up; proportions of participants in 25(OH) D categories were compared using Fisher exact test. Falls were assessed using monthly fall calendars, and rate of falls was estimated using negative binomial generalized estimating equation models. RESULTS: Mean +/- standard deviation 25(OH) D concentrations were 20.9 +/- 11.5 ng/mL at baseline, with 57% having 25(OH) D concentrations less than 20 ng/mL. Retention and adherence were high (> 90%). After the 5-month intervention, only one of 34 participants randomized to vitamin D3 had 25(OH) D concentrations less than 20 ng/mL, compared with 18 of 25 participants randomized to placebo (P < .001). In unadjusted analyses, the rate of falls over 5 months was not significantly different according to intervention group (risk ratio (RR) = 0.48, 95% confidence interval (CI) = 0.19-1.19), but after adjustment for sex, race, season of year, baseline 25(OH) D status, and history of falls, participants randomized to vitamin D3 had a lower rate of falling than those randomized to placebo (RR = 0.42, 95% CI = 0.21-0.87). CONCLUSION: A vitamin D intervention delivered through MOW was feasible, resulting in improvements in 25(OH) D concentrations and a lower rate of falls in adjusted analyses. Further research is needed to validate the reduction in falls from this type of intervention.