According to the World Health Organization (WHO), infertility is a reproductive system disorder defined as the inability to achieve a clinical pregnancy after 12 or more months of regular unprotected sexual intercourse. It is estimated that 10-15% of couples experience infertility, making it a significant global public health issue. In one-third of infertile couples, the cause of infertility is attributed to female factors, in one-third to male factors, and in one-third of infertile couples, pregnancy does not occur due to a combined male and female factor, or the cause of infertility cannot be determined (idiopathic infertility). Due to the increasing prevalence of infertility, there has been a growing interest in identifying factors that affect fertility. One of the factors that has been shown to influence fertility is vitamin D, which is an important nutrient involved in numerous biological processes. It has been found that there is an increasing prevalence of vitamin D deficiency both in the general population and in the reproductive population. Based on available data from PubMed and other sources, this paper describes the current knowledge on the impact of vitamin D on fertility in women and men.