I just take a couple vitamins myself as I feel I can obtain most from my diet, When it comes to vitamin D, iodine, and fish oil I supplement. I keep my D3 levels between 60 to 70ng/ml year round. It typically takes 6000ius for me to do that.
I learned how to take and test D3 hormone levels correctly from Dr Davis. heartscanblog.blogspot.com/2010/01/getting