Out of curiosity, I looked up the effects of taking too much vitamin D, and:

> Recent epidemiologic evidence suggests that there is a narrow range of vitamin D levels in which vascular function is optimized. Levels above or below this range increased mortality.[14] Animal research suggests that both excess and deficiency of vitamin D appears to cause abnormal functioning and premature aging.[42][43][44]

https://en.wikipedia.org/wiki/Hypervitaminosis_D

There's a bigger subsection on cardiovascular disease too, but all I can understand from it is "it's complicated".