MedicalResearch.com: What are the main findings of the study?
Answer: That among patients with established coronary artery disease there was no observable relationship between the amount of vitamin D circulating in their blood and the extent of disease progression during the following year.
MedicalResearch.com: Were any of the findings unexpected?
Answer: Based on the results of cross-sectional studies and the mechanistic framework provided by animal and in-vitro studies, we thought that a role in atherosclerosis could explain why vitamin D status was associated with cardiovascular events in many large observational cohorts. Knowing that few longitudinal studies had investigated the relationship between vitamin D status and the extent of coronary artery disease, we believed that any effect of vitamin D would become evident in our observational data and were excited about this. Right now, taking recent publications in to account, vitamin D status does not seem to be relevant to disease progression. However, some studies report an association with disease development.
MedicalResearch.com: What should clinicians and patients take away from your report?
Answer: Provided that the patient with coronary artery disease is sufficient (25-hydroxyvitamin D concentration above 50 nmol/L) in vitamin D and receive adequate treatment, we do not observe any beneficial contribution from vitamin D status in terms of slowing down disease progression.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Answer: Groups that have data available on repeated measurements of coronary artery disease and vitamin D status should analyse this relationship and publish their findings. The literature is scarce and these results are important. There are some large ongoing randomised placebo controlled trials assessing the effect of vitamin D on cardiovascular events. The VITAL trial in USA, with expected results in 2016, also planned sub studies assessing the effect of vitamin D supplements on soft end-points using non-invasive imaging techniques. Provided that they do find an effect of vitamin D on the risk of myocardial infarction, the results regarding soft end points would be very exciting indeed.