 WDEL Newstime now is 845. Those multivitamins you take religiously on a daily basis, what are they really doing to improve your health? A new study from the National Institutes of Health suggests a daily multivitamin may not help you live a longer life. Researchers looked at data on more than 400,000 healthy U.S. adults over 20 years and found no differences in mortality or risk of death for those who took multivitamins versus those who did not.