A new study has shown that exposure to sunlight boosts fertility in both men and women by increasing their levels of vitamin D. Vitamin D balances sex hormones in women and improves sperm count in men, according to the research.
In women, vitamin D boosts levels of the sex hormones progesterone and estrogen, which helps to regulate menstrual cycles and make conception more likely. In men, vitamin D is essential for the healthy development of the nucleus of the sperm cell.
According to the Daily Mail:
“It also increases levels of the male sex hormone testosterone, improving a man’s libido ... The vitamin’s effect on both male and female sex hormones may explain why conception rates fall in the winter and peak in the summer in Northern European countries”.