Unfortuneatly, chemtrails are interfering with our ability to get UVB rays.
In winter, there is a very short window of opportunity for UVB even in Equador near the equator.
The thyroid uses hormones too and hormones means their are receptors all over the whole body, so it very logical to assume that hypo T or any thyroid issues would definately interfere with immune system responses.
I really think the immune system is regulated by vitamin D and thyroid, which is why I am back on this site.
Iodine is so crucial to immune functions, as well as, D and the gut flora.