An additional observation of interest was the absence of differences in the effects of cabergoline between two groups of women with prolactin levels within the reference range: vitamin D-naive women and women receiving exogenous calciferol due to a history of hypovitaminosis D. This finding suggests that the potent effects of cabergoline in vitamin D-treated hyperprolactinemic women reflect normal vitamin D status, and cannot be explained by the supplement’s effect. This evidence concerns the gene PRL and rickets.