Biotin deficiency significantly reduces testosterone, LH and testicular function
https://www.ncbi.nlm.nih.gov/pubmed/2515138
https://dyuthi.cusat.ac.in/jspui/bitstream/purl/650/1/C%20S%20Paulose%20and%20others(1989)march9.PDF
Biotin deficiency reduced LH and testosterone.
Administration of LH restored testosterone production.
This suggestions biotin was reducing testosterone by reducing LH.
The question is how and where in the HPA this was occuring
Note: Avidin, found in raw egg whites can interfere with biotin absorption. Avidin is deactivated by cooking, but cooking method and time is important. This study found that http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2621.1991.tb05361.x/abstract Mean residual avidin activity in fried, poached and boiled (2 min) egg white was 33, 71 and 40% of the activity in raw egg white. Total inactivation required 4 mins of boiling.
Cradle cap and Seborrheic dermatitis may result from biotin deficiency.