So, does that mean vitamin D deficiency leads to autoimmune disease or that those with autoimmune disease are more likely to be deficient in Vitamin D?? Unfortunately, the researchers haven’t figured that one out yet and/or only offer opinion.
The one thing researchers do know is “thyroid treatment isn’t optimal — and may not work — if you do not have adequate vitamin D for the crucial final metabolic step, which takes place at the site where thyroid hormone actually works. This happens inside the nucleus of the cell. Vitamin D needs to be present at sufficient levels in the cell in order for the thyroid hormone to actually affect that cell. That is why vitamin D is so crucial.”