Molybdenum

Molybdenum strongly inversely correlated to testosterone in men
https://www.ncbi.nlm.nih.gov/m/pubmed/18990371/

Urinary molybdenum inversesly correlated to testosterone in nationally representative sample
https://www.ncbi.nlm.nih.gov/m/pubmed/25439796/?i=2&from=/18990371/related

Ram study: Molybdenum sulfate suppelementation reduces testosterone - perhaps due to creating a copper deficiency
https://www.ncbi.nlm.nih.gov/pubmed/2724283
- Molybdenum alone didn't seem to have much effect (but I'll need to see full text to confirm). Molybdenum sulfate did induce defficiency. Is it the sulfate???