Effect of vitamin B6 on the side effects of a low-dose combined oral contraceptive

Contraception. 1997 Apr;55(4):245-8. doi: 10.1016/s0010-7824(97)00005-x.

Abstract

Analogous to recommendations for treatment of side effects of early pregnancy and premenstrual syndrome, use of vitamin B6 has been recommended for the treatment of side effects of oral contraceptive (OC) use. A randomized, triple-blinded controlled trial of 124 women was done to evaluate the effect of taking 150 mg of vitamin B6 daily for 30 days on the severity of nausea, headache, vomiting, dizziness, depression, and irritability associated with the initiation of low-dose (30 micrograms norgestrel and 30 micrograms ethinyl estradiol) OG use. The severity of the symptoms was measured on a scale from 0 to 3 (not present to severe), and was evaluated at one month after admission. The two treatment groups (vitamin B, and placebo) had comparable baseline characteristics. From admission to follow up, there was a decrease in the severity of all symptoms in both groups. There was no statistically significant difference in the reductions found in the vitamin B6 and the placebo groups, although reductions in the severity of headache and dizziness were greater in the B6 group. The decrease in the severity of all OC side effects can be explained more by a placebo effect than by a marginal pharmacological effect of the vitamin B6.

PIP: Use of vitamin B-6 has been recommended for the treatment of side effects associated with combined oral contraceptive (OC) use. To evaluate this recommendation, a randomized, triple-blinded controlled trial of 124 women recruited from 2 health centers in Zacatecas, Mexico, was conducted. 62 women received 150 mg of vitamin B-6 daily for 30 days, while the remaining 62 received a placebo. All cases and controls were new or continuing users of an OC containing 30 mcg of norgestrel and 30 mcg of ethinyl estradiol. Women rated the severity of 6 common OC side effects (nausea, headache, vomiting, dizziness, depression, and irritability) on a scale from 0 to 3 at baseline and 30 days after admission. There was a decrease in the severity of all 6 symptoms in both groups. Although higher proportions of women in the vitamin B-6 group reported decreases in OC-related side effect severity between admission and the 30-day follow-up visit, these differences were appreciable only for headache and dizziness and none was statistically significant. No evidence of vitamin B-6 toxicity was observed. However, this study failed to substantiate a clinically important pharmacologic effect of vitamin B-6 on OC side effects.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Contraceptives, Oral, Combined / adverse effects*
  • Dizziness
  • Ethinyl Estradiol / administration & dosage
  • Ethinyl Estradiol / adverse effects
  • Female
  • Headache
  • Humans
  • Nausea
  • Norgestrel / administration & dosage
  • Norgestrel / adverse effects
  • Placebos
  • Pregnancy
  • Pyridoxine / administration & dosage
  • Pyridoxine / therapeutic use*

Substances

  • Contraceptives, Oral, Combined
  • Placebos
  • Norgestrel
  • Ethinyl Estradiol
  • Pyridoxine