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There is a difference of opinions on whether vitamins can help reduce the risk of certain cancers and heart disease. Drazen/Getty Images
  • Members of a high-profile task force say there isn’t enough evidence to support a recommendation for using vitamins as a way to reduce the risk of cancer and heart disease.
  • Some experts, however, say the issue should be explored because vitamins appear to have some preventive properties and don’t have serious side effects.
  • In addition, some cancer survivors tell Healthline they are believers in the preventive power of vitamins and take them daily.

For millions of people in the United States, staying healthy includes a daily regimen of vitamins and/or supplements.

According to the U.S. Centers for Disease Control and Prevention, more than half of surveyed U.S. adults used at least one dietary supplement in 2018.

Most people interviewed by Healthline for this story said they believe that vitamins and/or supplements can keep diseases at bay.

However, the U.S. Preventive Services Task Force (USPSTF), an independent panel of national experts in disease prevention and evidence-based medicine, concluded in a report published today that the evidence is “insufficient” to determine the balance of benefits and harms of supplementation with multivitamins for the prevention of cancer and cardiovascular disease.

In an editorial running today in the Journal of the American Medical Association, scientists at Northwestern Medicine said they support the USPSTF’s findings.

For non-pregnant, otherwise healthy Americans, vitamins and supplements are a “waste of money” for those who think they can help prevent cardiovascular disease or cancer, the Northwestern scientists wrote.

“Beyond wasted money, the focus on supplements might be viewed as a potentially harmful distraction. Rather than focusing money, time, and attention on supplements, it would be better to emphasize lower-risk, higher-benefit activities,” the scientists added.

Dr. Jenny Jia, a co-author of Northwestern’s editorial, told Healthline that if people really want to focus on preventing chronic diseases such as cancer and heart disease, “they need to focus on evidence-based lifestyle behaviors, including eating a balanced diet and exercising regularly every week.”

Dr. Jeffrey A. Linder, the chief of general internal medicine in the department of medicine at Northwestern University Feinberg School of Medicine in Illinois, said in a press statement, “Patients ask all the time, ‘What supplements should I be taking?’ They’re wasting money and focus thinking there has to be a magic set of pills that will keep them healthy when we should all be following the evidence-based practices of eating healthy and exercising.”

“The task force is not saying ‘don’t take multivitamins,’ but there’s this idea that if these were really good for you, we’d know by now,” he added.

Despite these conclusions, there is still support among some patients and physicians that vitamins and supplements can have a positive effect on disease.

Gordon Saxe, PhD, MPH, is an oncologist and the director of the UC San Diego Center for Integrative Nutrition and chair of the Krupp Endowment for research on the benefits of natural complementary and alternative medicine.

He’s conducted research on the epidemiology of diet and gene expression as well as prostate, breast, and pancreas cancer.

“Conservative bodies like USPSTF dismiss supplements because of the lack of evidence, but many of these supplements have simply not been adequately studied,” Dr. Saxe told Healthline.

“We should be more open and curious and not fear these things or be dismissive,” he said. “It’s one thing to say that there have simply not been enough studies of these supplements, but it’s another to dismiss them as if the lack of evidence implies that they don’t work.”

Saxe said that evidence from ecological epidemiological studies suggests that vitamin D might in fact be protective against a number of common cancers, including breast cancer and colon cancer.

“But the data is not perfect and it needs to undergo rigorous trials before we can conclude that it is for sure preventive or therapeutic,” he said.

“Vitamin D needs to be studied more, and I am not asserting that it will prevent cancer. But it may. And the harm is minimal, so why not?” Saxe added.

Patients interviewed for this story say they take vitamins and/or supplements and believe they can help with cancer, cardiovascular disease, and other health issues.

“All of my doctors recommend vitamin D,” said Mia Dansky Blitstein, a non-Hodgkin’s lymphoma survivor.

“My doctors recommended vitamin D3 for stage 2 lung cancer,” added Jean Walcher.

Katherine Page had stage 2 breast cancer when she was 36. It has not returned.

“I try to eat a lot of omega-3 fatty acids by taking a pill and eating a lot of power seeds like flax, pumpkin, and almond,” she told Healthline.

“I also drink only water or green tea. Lots of green tea. I take turmeric and vitamin D. I do not eat red meat and every morning I have antioxidants in the form of berries either with the seeds and yogurt or oatmeal or a smoothie,” she added.

Nonetheless, some people interviewed by Healthline agree with the new guidelines:

“My mom did the holistic route with breast cancer,” said Bill Ray, a professional musician. “She got cancer, took about a week of chemo, then began doing the whole cannabis/vitamins route.”

Ray said his mom delved deep into things he had never heard of such as Rh-negativity and more.

“It took her about two years to go overall. It wasn’t pretty,” he said. “Those I’ve known who went the holistic route, the outcome was much sadder. This is something that concerns me, as both my grandparents and my mother succumbed to cancer, and it’s probably what will take me out.”