title: Oral ascorbic acid increases plasma oestradiol during postmenopausal hormone replacement therapy.
abstract: OBJECTIVE
  To study the possible interaction between ascorbic acid (AA) and oestradiol (E2) in postmenopausal women on hormone replacement therapy (HRT).
  
  
  METHODS
  We studied 25 healthy postmenopausal women who had used percutaneous E2 gel at same dose for 10-12 months, at which time the plasma E2 concentrations were stabilized. The subjects were treated with 1000 mg of AA daily for 3 months and blood samples for assay of AA and E2 were taken at 0, 1 and 3 months.
  
  
  RESULTS
  After 1 month of AA treatment, there was an overall increase of 20.8% in E2 levels in the group as a whole. Greater responses were seen in two subgroups. In women with initially the lowest plasma concentrations of AA (<70 micromol/l), there was an increase of 55% in plasma E2 levels which was close to significance (P=0.063). In another subgroup with initially the lowest E2 levels (<0.20 nmol/l) there was a marked and significant increase (from 0.13 to 0.26 nmol/l) in plasma E2 concentrations (P=0.028).
  
  
  CONCLUSIONS
  Our results support early findings that AA may interact with oestrogen therapy. Possible interaction of AA with E2 at the level of antioxidation is discussed.
authors.affiliation: Department of Obstetrics and Gynecology, Tampere University Hospital, PO Box 2000, 33521, Tampere, Finland. tarjavi@sgic.fi
authors.forename: Tarja
authors.initials: T
authors.lastname: Vihtamäki
authors.forename: Jouko
authors.initials: J
authors.lastname: Parantainen
authors.forename: Anna-Maija
authors.initials: AM
authors.lastname: Koivisto
authors.forename: Timo
authors.initials: T
authors.lastname: Metsä-Ketelä
authors.forename: Risto
authors.initials: R
authors.lastname: Tuimala
mesh_terms: D001205:Ascorbic Acid / Q000008:administration & dosage* / Q000627:therapeutic use; D004958:Estradiol / Q000097:blood*; D015914:Estrogen Replacement Therapy; D005260:Female; D006801:Humans; D008875:Middle Aged; D017698:Postmenopause; D013997:Time Factors
chemical_list: D004958:Estradiol; D001205:Ascorbic Acid