Yup, here is the first paper from a google search on that topic https://www.ncbi...

Yup, here is the first paper from a google search on that topic https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6071442/ There are a number of ways to hack the hpa-axis, vitamin D being an cheap and easy one.

Worth noting that there are plenty of reasons why the hpa-axis might shift one way or another, lack of vitamin D is simply one of many. Chronic pain would be another (which low dose naltrexone often works well for).