Hypovitaminosis A was found to be an important cause of menorrhagia, and a statistically significant difference between the fasting serum vitamin A values of healthy controls and patients with menorrhagia was noted. Vitamin A is a co-factor of 3 beta-dehydrogenase in steroidogenesis and deficiencies of this vitamin may result in impaired enzyme activity. The level of endogenous 17 beta-oestradiol appears to be elevated with vitamin A therapy, and menorrhagia was alleviated in more than 92% of patients.