1 in 3 Americans take multivitamins every day to boost their health, but a new study suggests they might not be as useful as you think. It looked into the association between long-term, daily multivitamin use and mortality in healthy adults, and found they won’t actually help you live longer. Taking multivitamins won’t help you live longerThe study, which was published in the JAMA journal, analyzed data from 390,124 adults without a history of cancer or other chronic diseases. All of the participants were followed up at least 20 years later, and the study concluded that multivitamin use was “n…