Get sunlight! Sunlight provides Vitamin D, and Vitamin D is a steroid hormone, that is essential for the healthy development of the nucleus of the sperm cell, and helps maintain semen quality and sperm count. Vitamin D also increases levels of testosterone, which may boost libido. Now this does not mean go and over due it, because anything in excess can lead to long term issues.
* Note. We are not a medical source and recommend you consult a doctor for further review.