Vitamin D Status Determines the Effect of Cabergoline on Sexual Function and Depressive Symptoms in Hyperprolactinemic Women

<i>Background/Objectives</i>: Although untreated prolactin excess is often associated with female sexual dysfunction, sexual functioning improves after chronic administration of dopamine agonists, including cabergoline. Extra-sexual benefits of cabergoline therapy were found to be less pronounced in young hyperprolactinemic women in the case of coexistent hypovitaminosis D. Thus, the present study was aimed at investigating whether vitamin D status also determines cabergoline action on sexual function and depressive symptoms in reproductive-age women. <i>Methods</i>: This prospective cohort study included 75 young women with prolactin excess, who, depending on vitamin D status, were assigned to one of three groups. Females with vitamin D deficiency (group A), vitamin D-insufficient women (group B) and vitamin D-sufficient women (group C) were matched for age, body mass index, blood pressure and prolactin levels. For the following six months, they received cabergoline. Before and after cabergoline treatment, all participants completed questionnaires evaluating female sexual functioning (FSFI) and depressive symptoms (BMI-II). The remaining outcomes of interest included plasma levels of 25-hydroxyvitamin D, prolactin and sex hormones. <i>Results</i>: Before treatment, there were no differences between the study groups in sexual functioning and mood. The study groups differed in post-treatment levels of 25-hydroxyvitamin D, prolactin, testosterone and estradiol. Although cabergoline reduced the total FSFI score and improved functioning in all domains of the FSFI questionnaire, this effect was strongest in group C and weakest in group A. Statistically significant changes in the BDI-II score were observed only in group C. The increase in the total FSFI score and domain scores correlated with the decrease in prolactin levels, 25-hydroxyvitamin D levels, the increase in testosterone and estradiol concentrations, and the reduction in the BDI-II score. <i>Conclusions:</i> Low vitamin D status attenuates the beneficial effects of cabergoline on sexual function and depressive symptoms in reproductive-age women.