Taking a B vitamin supplement that contains niacin could put people at an increased risk of heart disease, according to a new study.Led by researchers from the Cleveland Clinic, the study showed that as many as 1 in 4 people have a higher-than-recommended level of niacin. When the body breaks down niacin, it creates a byproduct called 4PY that triggers inflammation in the body’s circulatory system. That inflammation damages blood vessels and, ultimately, can lead to a buildup which significantly raises the risk of a stroke, heart attack, or other major heart problems.