I haven't heard anything about a correlation with heart but even back in the 1960s, it was known there was less MS in the south. They didn't know why, but my DH's father gave up his Manhattan career and moved his wife and youngest daughter to Florida in hopes of delaying progression of MS. There is less breast cancer in women with Vit D above 50, so that is my minimum goal. I do my best to depend on sun for the Vit D, but as Dr. Davis said, the older we get, the harder it is to convert sun on skin into Vit D. I supplement, get sun most of the year, and test every February.
Found this study on MS, others on cancer and diabetes, but don't see one on CVD.
https://www.ncbi.nlm.nih.gov/pubmed/10871801 MS and Vit D: https://www.ncbi.nlm.nih.gov/pubmed...rosis+vitamin+d