Forty-two healthy young adults (mean age, 24.4 years) with a current sexual partner were randomly assigned to receive, in double-blind fashion, 3,000 mg/day of vitamin C or placebo for 2 weeks. Among women, the frequency of sexual intercourse during the study was significantly greater in the vitamin C group than in the placebo group (mean, 10.3 vs. 3.7 episodes per month; 178% increase; p = 0.03). Vitamin C had no significant effect in men (mean episodes per month: vitamin C, 5.9; placebo, 6.3). The increase in intercourse frequency occurred only among non-cohabitants, whereas in cohabitants, vitamin C supplementation was associated with a nonsignificant decrease in frequency. The vitamin C group also experienced a decrease (improvement) in Beck Depression scores, whereas no change was seen in the placebo group.

Comment: Supplementation with vitamin C led to an increase the frequency of sexual intercourse among women not living with their sexual partner. The specificity of the effect to that subset of the study population suggests that vitamin C acts on the brain in a way that reduces inhibitions. Previous studies have shown that administration of vitamin C decreases reactions to stress and improves approach anxiety, effects which may influence sexual behavior and mood.

Brody S. High-dose ascorbic acid increases intercourse frequency and improves mood: a randomized controlled clinical trial. Biol Psychiatry 2002;52:371-374.