Boron: Scientific study showing 11mg/day boron boosts free testosterone:
http://www.ncbi.nlm.nih.gov/pubmed/21129941
2011
Iodine boosts testosterone:
http://www.peaktestosterone.com/Testosterone_Iodine.aspx
https://www.scribd.com/doc/222400050/The-Secret-That-Doubles-Testosterone
Selenium for Testosterone | Benefits and Side Effects
http://iast.net/testosterone-booster-ingredients/selenium-benefits-and-side-effects/
Magnesium Oil for Higher Testosterone (1 gram/day)
http://www.dangerandplay.com/2012/04/19/magnesium-oil-for-higher-testosterone/
Copper and zinc: Correlation between serum testosterone level and concentrations of copper and zinc in hair tissue.
http://www.ncbi.nlm.nih.gov/pubmed/21671089
Cobalt is necessary for the proper retention of estrogen, testosterone, cortisol, Jonathan Wright MD
http://www.fatnews.com/index.php/weblog/comments/cobalt-is-necessary-for-the-proper-retention-of-estrogen-testosterone-corti
Potassium Study: Potassium and Testosterone with Body Builders
http://www.fitflex.com/potassiumtest.html
52 Evidence-Based Ways to Increase Testosterone Levels Naturally
https://www.anabolicmen.com/how-to-increase-testosterone-levels-naturally/
--barely mentions iodine, copper, potassium
also neglects cobalt.