Double-blind Randomised Controlled Trial Of Vitamin D3 Supplementation For The Prevention Of Acute Respiratory Infection In Older Adults And Their Carers (ViDiFlu)
Notes for this study:
||Proportion with 1 or more. Placebo: 44/90 (49%) Intervention: 63/124 (51%). Rate per participant-year. Placebo: 91/93.6=0.97 Intervention: 130/130.0=1.00
|Number of Subjects
In a randomized, double-blind, placebo-controlled trial 137 participants in sheltered-accommodation housing blocks received 2.4 mg of vitamin D once every 2 months with 10 μg daily for residents and 3 mg once every 2 months for carers, 103 participants were allocated to control of placebo every 2 months with 10 μg daily vitamin D for residents and only placebo once every 2 months for carers. This persisted for one year.
The primary outcome was the time until the first acute respiratory infection and there was not a statistically significant difference in the median time, though it was somewhat shorter for the intervention group. The proportion of participants with 1 or more acute respiratory infections was a little higher for the intervention group, and the duration was nonsignificantly higher.
For upper respiratory tract infections in particular, the rate was significantly higher for the intervention group. The rate was nonsignificantly higher for lower respiratory infections.
At baseline, the mean/standard deviation vitamin d levels were 42.4 (23.4) nom/l for the intervention group and 43.6 (22.6) for the control group. After 2 months, this was 65.5 (19.8) and 52.9 (21.7), and after 12 months, this was 85.3 (24.3) and 59.1 (26.0).