Are your multivitamins keeping you awake? The short answer is "possibly, but probably not." Writing in the New York Times, Anahad O'Connor tackles the widely accepted conviction that multivitamins can disrupt our sleep. O'Connor cites a 2007 study of hundreds of people who answered questions about sleep and vitamins, and found a slightly higher rate of poor or interrupted sleep in people taking multivitamins, but not enough of a connection to draw any scientific conclusions. He also reports that studies have shown that ingesting vitamin B6 before bed can lead to very vivid dreaming, and that vitamin B6 helps the body convert tryptophan to serotonin, a hormone that affects sleep. Other studies have shown that vitamin B12 can affect melatonin levels, promoting wakefulness. What to do if you suspect that vitamins are keeping you up? O'Connor suggests taking your vitamins in the morning.