Vitamin K2 MK4 boosts testosterone production in rats without boosting LH
https://www.ncbi.nlm.nih.gov/pubmed/21914161
"At the end of the experimental feeding period, testosterone levels in the testis were significantly increased in the MK-4 sup group, although plasma levels of luteinizing hormone (LH) remained unchanged (Figures 1B and 1C). Therefore, an MK-4-supplemented diet can enhance testosterone production in the testis in a manner that is independent of LH."
Vitamin K deficiency reduces testosterone in rats
https://www.ncbi.nlm.nih.gov/pubmed/16844298
Dietary vitamin K alleviates the reduction in testosterone production induced by lipopolysaccharide administration in rat testis
https://www.ncbi.nlm.nih.gov/pubmed/21894328
Hypothesis: The role of Vitamin K in prostate health
https://www.ncbi.nlm.nih.gov/pubmed/25613567
Nice idea… but I don't think vitamin K is powerful enough alone to do this.
https://www.google.com/patents/US8686049
Unfortunately, personal experience suggests that any possible boost in testosterone may be outweighed by downregulation of 5AR
Both phylloquinone (Vitamin K1) and menaquinone 7 (Vitamin K2 MK7) inhibit 5AR
https://www.ncbi.nlm.nih.gov/pubmed/10746179
MK7 contributes to serum vitamin k status in women, MK4 doesn't
https://www.ncbi.nlm.nih.gov/pubmed/23140417
**BUT oral MK4 does have physiological effects on women's bone health, so it must be doing something **
https://www.ncbi.nlm.nih.gov/pubmed/23702931
https://www.ncbi.nlm.nih.gov/pubmed/19352059