There have been a tremendous number of studies on Vitamin D, but there have been few studies looking at autoimmunity and Vitamin D.

Vitamin D could be a cause and/or a potential treatment for autoimmune thyroid.

http://www.ncbi.nlm.nih.gov/pubmed/26637501

Thinking about this post and Vit D, depression and thyroid dsyfunction.

Personally, in 1991 I was 53 and had come in from years of SUN. I was struggling with depression which went on for 10 yrs and blamed it on sluggish thyroid but the doctor's numbers kept saying I was normal/OK etc etc. NEVER thinking of the Vit D issue.

Then finally in 2002, my D.O. called in for desiccated thyroid and that 10 yrs of depression lifted. I was feeling good, no depression and then in late 2006 a lowness hit me and talking to my sister who struggles with MS, she was talking about the importance of Vit D and I never thought I'd be Vit D deficient...I live in So. Cal..but I'm NOT in the sun much at all anymore. I brought this up to an MD I was seeing and he did the Vit D test and I was about in the tank, and he tested himself and he was lower than me.

I got on Vit D dosing in 2006 and have been testing annually etc and levels are pretty good. I was optimal at 80 and then after hip replacement, Vit D dropped 40 pts...which I had read could happen with surgery. These days I'm probably at 50-60 give or take.

So as I'm thinking about all this Vit D is so critical and COULD help with thyroid etc and it all. Getting there and realizing this is how it all came about for me. All those years of depression I was living in I was probably Vit D deficient and had no idea, blaming it on sluggish thyroid....Probably both...but going the Vit D seems to be the FIRST line of attack as I see it now. What I know now is no where near what I knew in 1991 and for those 10 yrs. Anyway, my experience. C

Good info on K2 for D3 effectiveness , how much to take etc. People are asking and one person gave us this info to digest:

https://www.youtube.com/watch?v=jPWCJxyHAg4