A system for improving vitamin D nutrition in residential care

Objective: To assess the feasibility of administering an inexpensive preparation of vitamin D3 100 000 IU orally 3 monthly to aged‐care residents. Design: Prospective, controlled open‐label implementation trial. Setting: Residential aged care, November 2003 to May 2004 (primary study). Participants: 137 ambulant residents: 107 treated (mean age, 85 years; 79 were women), 30 untreated controls (mean age, 87 years; 22 were women). Interventions: Lactose microencapsulated vitamin D3 100 000 IU orally at baseline, then 3 monthly (three or more doses); untreated subjects were observed contemporaneously. Main outcome measures: Serum levels of 25‐hydroxyvitamin D [25(OH)D] at 6 months compared with baseline; acceptability of the program to residents and staff. Results: At baseline, 95% of residents assessed (n = 137) had serum 25(OH)D levels below the desirable range of 60–160 nmol/L. At 6 months, all treated residents (n = 98) achieved desired levels, with the mean (± SD) 25(OH)D level increasing from 36.4 ± 12.6 nmol/L (range, 12–75 nmol/L) at baseline to 124.0 ± 27.9 nmol/L (range, 68–244 nmol/L). In no resident did 25(OH)D approach toxic levels. The mean serum 25(OH)D level remained low in the control group (n = 27): 42.8 ± 18.3 nmol/L (range, 18–98 nmol/L). The difference between the mean 25(OH)D levels of treatment and control groups at 6 months was 81.2 nmol/L (95% CI, 69.7–92.0 nmol/L). The cost of the supplement was $4 per resident per annum. Substudies showed mean trough serum 25(OH)D levels in the desired range at 3 months (n = 31), but below the desired range at 6 months (n = 50). Subjects given 3‐monthly doses for up to 2 years maintained serum 25(OH)D levels within the desired range, with no trend toward undesirable accumulation (n = 11). Conclusions: Vitamin D3 100 000 IU given orally 3 monthly is a practical, safe, effective and inexpensive way to meet the vitamin D3 requirements of aged‐care residents.