 We just have to hold that faith and know that that rain's coming and it will come in time. Is a multivitamin every day really providing a health boost? 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.