A recent, non-peer-reviewed study found an increased risk of heart disease among people who took melatonin. Dr. Frita Fisher says the study's conclusion contradicts years of research and that a more rigorous trial is needed. #health #melatonin Start your day with "Morning in America," NewsNation's live three-hour national morning newscast hosted by Markie Martin. Weekdays starting at 6a/5C. #MorningInAmerica NewsNation is your source for fact-based, unbiased news for all Americans. More from NewsNation: newsnationnow.com Get our app: trib.al/TBXgYpp Find us on cable: trib.al/YDOpGyG How to watch on TV or streaming: trib.al/Vu0Ikij