EARLY EFFECT OF A LOW-DOSE (30 MU-G) ETHINYL ESTRADIOL-CONTAINING TRIPHASIL(R) ON VITAMIN-B-6 STATUS - A FOLLOW-UP-STUDY ON 6 MENSTRUAL CYCLES

The objectives of the study were to follow-up six artificial menstrual cycles induced by Triphasil(R) in order to determine: 1) the time of apparition of B-6 metabolic side-effects, in the eventuality they occu r, and 2) the existence or non-existence of a normalization process an d if so, when it is initiated. The choice of this triphasic OC prepara tion was based on its current popularity among modern gynecologists. A mong the selected twenty-three young women who had never used oral con traceptives (OC), fourteen consented to try a new contraceptive method . Their nutritional status including anthropometric, hematologic, bioc hemical and dietetic (including vitamin B-6 intake) parameters was fou nd to be adequate. A functional enzymatic rest coupled to a direct mea surement of vitamin B-6 was employed to obtain a complete assessment o f their vitamin B-6 status. By using both approaches, only one case (7 %) of deficiency due to OC was evidenced. This well-controlled study r evealed that a short-term use of a relatively low dose estrogen-contai ning OC (30 mu g) did not alter PLP concentrations in plasma and eryth rocytes in the majority of our young subjects consuming adequate diets . However, a disturbance in vitamin B-6 metabolism was detected. PL le vels in both blood components have increased steadily and did not subs ide to pretreatment values at the end of the experiment. In conclusion , the single use of the PLP vitamer can be misleading as demonstrated by other investigators. To assess B-6-status during oral contraception , in addition to a functional enzymatic test, it may be necessary to i nclude the other aldehydic form of vitamin B-6, to fully establish and comprehend hormone-induced adverse effects on this metabolism, partic ularly those of progesterone/progestin that have not yet been explored .