Daily Multivitamin Supplements Do Not Help You Live Longer, Study Finds

Taking daily multivitamins does not help people live longer and may actually increase the risk of early death, a new study has found. The study, published in JAMA Network Open, analysed nearly 400,000 generally healthy adults for more than 20 years and found that "multivitamin use to improve longevity is not supported". Surprisingly, instead of living longer, those who took multivitamins were actually 4% more likely to die than those who didn't take any, researchers said. 

For the study, Dr Erikka Loftfield and colleagues at the National Cancer Institute in Maryland analysed data from three major US health studies. All were launched in the 1990s and gathered details on participants' daily multivitamin use. The records covered 390,124 generally healthy adults who were followed for more than 20 years.

The researchers found no evidence that daily multivitamins reduced the risk of death. In fact, they reported a 4% higher mortality risk among users in the initial years of follow-up. The greater risk of death may reflect the harm multivitamins can cause or a trend for people to start daily multivitamins when they develop a serious illness, researchers said. 

Dr Neal Barnard, an adjunct professor of medicine at George Washington University and co-author of a commentary published alongside the study, explained that vitamins were useful in specific cases. Historically, sailors were saved from scurvy by vitamin C, while beta carotene, vitamins C and E, and zinc appear to slow age-related macular degeneration, a condition that can lead to severe loss of eyesight, he said. It is also the case that vitamins may be beneficial without reducing the risk of early death. 

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Yet "multivitamins overpromise and underdeliver," Dr Barnard said. "The main point is the multivitamins are not helping. The science is not there." Instead of taking multivitamins, we need to eat healthy foods, he said, which provide a broad range of micronutrients, macronutrients and fibre, while limiting saturated fat and cholesterol.

"What this study shows is that, generally, multivitamins aren't going to help you live longer," Dr Jade A Cobern, a board-certified physician in paediatrics and general preventive medicine, told ABC News. "Even though the cost of many multivitamins isn't high, this is still an expense that many people can be spared from," she added. 

Instead, Dr Cobert told the outlet that it's best for people to consume vitamins that come from diet rather than supplements. "We can all likely benefit from adding more vegetables and whole grains or legumes into our diets, reducing red meat intake, decreasing our sedentary time and reducing alcohol intake," she said.