The researchers noted that vitamins are useful in specific cases.
A group of researchers from the United States focused their study on a particular analysis: reviewing the medical records of a little more than 400,000 adult patients without chronic diseases with the purpose of understanding whether daily consumption of multivitamins reduced their risk of death. They followed these patients for 20 years.
In the results published in the journal Jama Networkthe team led by Dr. Erikka Loftfield, from the National Cancer Institute in Maryland, explains that they undertook the task of analyzing data from three major American health studies, which were launched in the 1990s.
“We excluded people with a history of cancer and other chronic diseases at the start of the study and those with missing data. “In addition, we adjusted for major mortality risk factors and, where possible, updated variables, such as smoking and BMI, in time-varying analyses,” the researchers explained.
After analyzing the data, the researchers found no scientific evidence that daily multivitamins reduced the risk of death. “On the other hand, we noticed that there is a 4% higher risk of mortality among users,” they say in the document and detail that this factor was noticed during the first years of patient follow-up.
The researchers also say that despite the popularity of multivitamins, it is essential to pay attention to their supplements, which they say can sometimes be harmful. One example they give is iron, which is added to many multivitamins, as “it can cause iron overload and increase the risk of cardiovascular disease, diabetes and dementia,” they point out.
Among the limitations that the researchers presented in this research is that it is an observational study and, say the scientists, “residual confusion factors derived from poorly measured or unmeasured factors can bias risk estimates.”
For Neal Barnard, associate professor of medicine at George Washington University and co-author of one of the comments attached to the study, vitamins are useful in specific cases. However, “multivitamins overpromise and underdeliver. The main point is that multivitamins don’t help. The science is not there,” he added.
Among the recommendations provided by the researchers is to eat healthy foods, since “they provide a wide range of micronutrients, macronutrients and fiber, while limiting saturated fats and cholesterol.”
