Scragg 2011.

Trial name or title	ViDA (vitamin D assessment) trial
Methods	Randomised, double‐blind, placebo‐controlled trial using parallel‐group design (two intervention groups)
Participants	Country: New Zealand Estimated number of participants: 5100 Inclusion criteria: age 50 to 84 years; ability to give informed consent; resident in Auckland at recruitment; anticipated residence in New Zealand for the four‐year study period Exclusion criteria: current use of vitamin D supplements (> 600 IU per day if aged 50 to 70 years; > 800 IU per day if aged 71 to 84 years); diagnosis of psychiatric disorders that would limit ability to comply with study protocol (i.e. history of regular exacerbation of major psychosis (schizophrenia, bipolar disorder) in past two years); history of hypercalcaemia, nephrolithiasis, sarcoidosis, parathyroid disease or gastric bypass surgery; enrolled in another study, which could affect participation in the vitamin D study; serum calcium from baseline blood sample > 2.50 mmol/L
Interventions	Intervention group 1: vitamin D3 200,000 IU oral capsule at baseline, then 100,000 IU oral capsule monthly (aside from 200,000 IU oral capsule in each June); or Intervention group 2 (control group): placebo (sunflower lecithin) for four years
Outcomes	Incidence rate of fatal and non‐fatal cardiovascular disease, as assessed by mortality, hospital discharges and family doctors
Starting date	7/04/2011
Contact information
Notes