The Vitamin D Assessment (ViDA) study – Design and main findings. Issue 198 (April 2020)

• Record Type: Journal Article
• Authors: Scragg, Robert
• Is Part Of: Journal of steroid biochemistry and molecular biology. Issue 198(2020)
• Publication Date: 2020-04
• Subjects: Cancer -- Cardiovascular disease -- Clinical trial -- Falls -- Fractures -- Respiratory infection -- Vitamin D supplementation; Steroid hormones -- Periodicals; Biochemistry -- Periodicals; Hormones -- Periodicals; Molecular Biology -- Periodicals; Hormones stéroïdes -- Périodiques; Steroid hormones; Periodicals; 572.579
• DOI: 10.1016/j.jsbmb.2019.105562
• Languages: English
• ISSNs: 0960-0760

Abstract

Highlights: The ViDA study is a clinical trial of high bolus dose vitamin D supplementation. Vitamin D supplementation did not prevent the main disease outcomes. Beneficial effects for intermediate outcomes were seen in vitamin D deficiency. Future vitamin D trials should only include vitamin D deficient participants. Abstract: Accumulating evidence from observational studies indicates that vitamin D status is inversely associated with a many non-skeletal diseases. This has initiated the conduct of several large clinical trials to determine if high dose vitamin D supplementation (≥ 2000 IU/day or monthly equivalent) prevents non-skeletal disease including cardiovascular disease, cancer and mortality. One of these trials is the Vi tamin D A ssessment (ViDA) Study which recruited 5110 participants, aged 50–84 years, mostly from primary care practices in Auckland, New Zealand. The intervention was a capsule that contained either 100, 000 IU vitamin D3 or placebo, two of which were taken by each participant soon after randomization, and then monthly up to 31 July 2015 (median follow-up 3.3 years). Information on study outcomes came from self-completed questionnaires and health data collected routinely by the Ministry of Health. There was no effect of vitamin D on the main outcomes: cardiovascular disease, acute respiratory infections, non-vertebral fractures, falls and all cancer. In contrast, vitamin D increased persistence with taking statins among participants on long term statin therapy. Beneficial effects were seen also for lung function among ever smokers (especially if vitamin D deficient), and in participants with low 25-hydroxyvitamin D levels for bone mineral density and arterial function. The findings support future research being carried out mainly in people who are vitamin D deficient, although there are practical and ethical issues in recruiting such people into future vitamin D supplementation trials.