A limited number of case reports seem to point the interaction between thinning hair and a vitamin D deficiency. This research looked at the relationship between prolactin levels and vitamin D levels in women with hair loss. The anterior pituitary gland secretes a polypeptide hormone called prolactin, which has a variety of biological effects, including the capacity to encourage growth and have a proliferative influence on human keratinocytes. Calcium homeostasis is affected by this hormone as a result of deficiency in vitamin D. This study was conducted on 75 patients during the period from November 2019 to March 2021. Serum prolactin and vitamin D levels were measured by chemiluminescence through an immunoassay (automated) and fluorescence Immunoassay (FIA) for vitamin D measurement. Serum prolactin levels were significantly elevated in pregnant women with hair loss compared with healthy controls. Vitamin D and serum prolactin levels had a remarkable positive correlation (r = 0.661, P 0.005). Prolactin and vit. D may play a part in hair loss in women.