Aims & Outcomes
The aim of BEST-D is to establish the most appropriate dose of vitamin D to assess in a large outcome trial. The primary outcomes are:
- The difference in the proportion of individuals with 25(OH)D blood levels of >90 nmol/L between those alloctated 100 vs 50 µg vitamin D daily at the end of the study.
- The difference in mean 25(OH)D blood levels between those allocated 100 vs 50 µg vitamin D daily at the end of the study.
Analyses of the effects of daily vitamin D3 100µg vs placebo, vitamin D3 50µg vs placebo, and between the two doses of vitamin D on:
- Mean levels of 25(OH)D during follow-up
- Proportion of patients with normal PTH at 6 and 12 months
- Differences in the change from baseline in various inflammatory markers at 6 and 12 months (CRP, BNP and inflammatory cytokines)
- Differences in change from baseline in BP, heart rate and arterial stiffness at 6 and 12 months
- Differences in the change from baseline in cholesterol levels and cholesterol sub-fractions and apolipoproteins at 12 months
- Nursing home residents
- Regular use of vitamin D supplements (>400 IU daily)
- Use of alendronate, risedronate, zoledronic acid, parathyroid hormone, or calcitonin
- Medically diagnosed dementia, history of hypercalcaemia, hyperparathyroidism, lymphoma, sarcoidosis, active tuberculosis, or renal stones
- Poor compliance with clinic visits or with medication
- History of alcohol or substance misuse
- Medical history that may limit participation for the duration of the study (e.g. terminal illness)
- Prescribed calcium supplements.