According to a study published in theJournal of Sexual Medicine, niacin, or vitamin B3 – found in chicken, fish and grains — may help men with erectile dysfunction if they also have high cholesterol. The results indicate that the men in the study, who had moderate or severe erectile dysfunction, reported an improvement in their ability to maintain an erection after taking a niacin supplement for 12 weeks. The initial dose was 500mg niacin taken nightly to ensure that they had no adverse side effects from taking the vitamin. The dose was increased to 1000mg daily and then to 1500mg at week six, if tolerated, and then continued until the end of the study. The most common side effect was skin flushing and itching. Further studies are warranted.