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.
Single-blind, cluster randomized trial.
MOW, Forsyth County, North Carolina.
Community-dwelling homebound adults aged 65 to 102 (N=68).
MOW clients were randomized to vitamin D3 (100,000 IU/month; n=38) or active placebo (400 IU vitamin E/month; n=30) according to MOW delivery route.
Serum 25(OH)D was assessed at baseline and 5-month follow-up; proportions of participants in 25(OH)D categories were compared using the Fisher exact test. Falls were assessed using monthly fall calendars, and rate of falls was estimated using negative binomial generalized estimating equation models.
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).
A vitamin D intervention delivered through MOW was feasible, resulting in improvements in 25(OH)D levels and a lower rate of falls in adjusted analyses. Further research is needed to validate the reduction in falls from this type of intervention.