This is a Youtube video by Dr Sarah Pugh, Phd in Biochemistry and Biophysics covering the importance and effects of Cholesterol, Vitamins and Sunlight on human health including the Thyroid. Sarah Pugh has a site "the busysuperhuman.com" that anyone trying to understand their health should visit. I have not included a link as they never work. Just search on YouTube.
"Cholesterol Myths & Truths A Quantum Biology & Biochemical Perspective"
A must watch, enjoy.