Acta Vitaminol Enzymol
Studies carried out in different countries during the last 15 years have provided evidence that supplementation with (or excess of) estro-progestational hormones may be accompanied by an increased urinary excretion of tryptophan metabolites, as happens in pyridoxine deficiency. Further methods of assessment of vitamin B6 in humans have confirmed an impaired status in women using hormonal contraception. Disturbances in the metabolism of tryptophan have been shown to be responsible for such symptoms as depression, anxiety, decrease of libido and impairment of glucose tolerance occurring in some of the OCA users. Administration of 40 mg of vitamin B6 daily not only restores normal biochemical values but also relieves the clinical symptoms in those vitamin B6 deficient women taking OCA’s. Further studies are justified to clarify whether vitamin B6 supplementation may contribute to improving depression also in other situations with hyperoestrogenism (pregnancy, puerperium, estro-progestational treatments, etc.), as well as correcting metabolic impairments, such as a minor alteration of glucose tolerance.