July 5, 2024 – Dr. Neal Barnard has a really clear message about multivitamins.
“Multivitamins are a commercial product looking for a market,” he said.
But Barnard can understand the explanations for taking multivitamins.
“The idea sounds sensible: 'You need certain vitamins and minerals, so let's put them all in one pill and you can be sure you'll be fine.' That makes sense for people who are deficient in one nutrient or another. But it carries significant risks for people who are at risk of overdosing on a vitamin or mineral.”
Barnard, an associate professor at George Washington University School of Medicine and Health Sciences in Washington, DC, is co-author of a commentary on a latest study that found that multivitamins have little effect on longevity and should actually pose some health risks.
Although an estimated one in three Americans takes these supplements, he said that usually, “you're better off without multivitamins.”
Barnard believes they are usually not giving us what nature intended.
For example, he said, “Vitamin E occurs in eight different forms in nature. So if you eat an almond or a walnut, you get eight different compounds called tocopherols. But if I put them in a multivitamin, I'm not getting all eight of them. I'm giving you one or two. So you may be upsetting the balance that nature intended.”
The latest large-scale studywhich combined data from three groups of people that were followed for 20 years, found that multivitamin supplements didn't reduce the chance of early death overall or of heart disease, cancer, or brain blood vessel disease. In fact, individuals who took vitamins each day had a 4% higher risk of overall mortality than those that didn't take them.
But there are advantages of some specific supplements, a comment because the study highlights. Dietary supplements corresponding to beta-carotene, vitamins C and E, and zinc slowed the progression of age-related macular degeneration. In addition, multivitamins have been shown to enhance memory and slow the decline of cognitive abilities in older people.
In addition, the commentary states, multivitamins generally is a “convenient source” of vitamins corresponding to B.12 and D, which many adults don't get enough of through their weight-reduction plan.
The study’s findings echo those of previous studies. In 2022, the US Preventive Services Task Force, an independent, voluntary panel of national experts, looked at some of these other studies and located no link between taking multivitamin supplements and deaths of every kind, cancer, or heart and vascular disease. However, the duty force didn't find enough evidence to recommend their use.
Dangers of multivitamins
Apart from the query of mortality profit, the impact of multivitamins on health should be considered, since multivitamins often also contain minerals corresponding to iron and copper.
Commenting on the brand new study, the authors said iron in multivitamins can have negative effects if users already get enough iron from their weight-reduction plan. Barnard said hemochromatosis, which may cause liver disease, heart problems and diabetes, may end up from an excessive amount of iron.
Centrum Silver, a standard multivitamin, doesn't contain iron, Barnard said. “That's a good idea, but they should leave it out of all multivitamins because no one should be taking iron unless there is a specific clinical need for it.”
He also warned in regards to the copper in multivitamin supplements, which he believes is linked to Alzheimer's disease.
Beta-carotene, he said, may protect against cancer when consumed through food, but increases the chance of cancer when taken in the shape of a multivitamin. The evidence for this finding got here from a study of smokers and asbestos employees who were prone to cancer.
John Wong, MD, vice chair of the U.S. Preventive Services Task Force and professor of medication at Tufts University School of Medicine in Boston, said that in light of this study, the duty force really helpful against taking beta-carotene to cut back cancer risk. However, he said the quantity of beta-carotene present in multivitamin supplements is way lower than the dose utilized in the study.
Other single vitamin supplements that will be dangerous include vitamin A in high doses, vitamin D in high doses, which may cause kidney stones, and vitamin E, which it said carries “some risk of hemorrhagic stroke.” The task force recommends against taking vitamin E.
When vitamin supplements are useful
The Task Force believes that some individuals with chronic diseases may profit from certain vitamins.
“This is related to chronic diseases that can affect the absorption or metabolism of certain vitamins,” Wong said. “Typically, these are nutrient deficiencies that can result from the chronic disease.”
These deficiencies could possibly be brought on by either a disease or a medicine, he said. For example, in a sort of pernicious anemia, a rare autoimmune disease, the body doesn't absorb vitamin B.12.
Jeffrey Kagan, MD, a general internist in Newington, CT, agreed that medications like Prilosec can reduce the power to soak up vitamin B12especially when people take them long-term for gastroesophageal reflux disease (GERD). When he prescribes any of those drugs to patients with GERD, he urges them to12 The fill levels are checked often.
Since most Americans have low vitamin D levels as a result of an absence of dairy and an excessive amount of time indoors, Kagan also recommends his patients take vitamin D supplements. If their blood tests show low protein levels, he recommends a protein complement like Ensure, which also accommodates loads of vitamins. For people healing skin wounds, he recommends vitamin C and zinc.
He also said, “Someone with cirrhosis of the liver, pancreatitis or Crohn's disease needs to improve their vitamin intake and diet.”
But he often prescribes specific vitamin supplements, not multivitamins, to individuals with specific conditions. When asked about multivitamins, he says, “My standard answer for the average healthy person is that they don't need multivitamins if they eat a balanced diet of meat, fruit and vegetables and don't have a specific problem.”
Eat right as a substitute of taking supplements
Both the Department of Health and Human Services and the American Heart Association recommend meeting dietary needs primarily through nutritious foods and beverages, and Wong says the Preventive Services Task Force agrees.
Barnard believes this too, but additionally believes that multivitamins will be harmful in some cases.
However, targeted dietary supplementation may be very useful. Vitamin B12 is a substance that many persons are deficient in. “But you don't have to take a cocktail of 15 different micronutrients to get vitamin B12.”
Instead of taking multivitamin supplements, Barnard said people should change their weight-reduction plan. The typical American weight-reduction plan tends to be too low in micronutrients corresponding to vitamin C, which is present in fruit and veggies, and too high in saturated fats and proteins as a result of excessive meat consumption.
Studies, he said, have shown that folks's health improves once they eat healthier. “They lose weight, their cholesterol and blood pressure go down, and their diabetes improves. Our work, which goes back 20 years, shows that in some people, diabetes disappears.” [Pioneering nutritional researcher] Dean Ornish's latest study shows that the course of the disease can improve within the early stages of Alzheimer's. The risk of cancer will be reduced and the course of the cancer will change in individuals who have already got the disease.”