Theoretical meta-analysis.
Link: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2726624/
From conclusion:
"Several recent epidemiologic studies have demonstrated a strong association between vitamin D insufficiency and risk of cardiovascular disease, risk of diabetes and metabolic syndrome. Several prospective studies have suggested that vitamin D deficiency predisposes individuals to increased risk of incident hypertension, ischemic heart disease, sudden cardiac death or heart failure."