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

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.