These popular supplements don’t measure up to health claims

By Naveed Saleh, MD, MS
Published June 24, 2021

Key Takeaways

If research proved that buying certain items with purported health benefits did not result in any gains, would you still buy them? Such is the case with various supplements. Much research has undermined the veracity of popular health claims promoted by supplement manufacturers. Nevertheless, the public keeps buying them.

According to Statista, in 2019, the average millennial customer—defined as born between 1981-1996—spent $62.73 per shopping trip on supplements, whereas members of the Greatest Generation—born between 1901-1927—spent $129.58 US dollars per trip.

That's a lot of dough for products that may or may not deliver on their promises. Here are four widely popular supplements that are not worth your money, according to health experts.


Many people take omega-3 fatty acid supplements containing eicosapentaenoic acid (EHA) and docosahexaenoic acid (DHA) to decrease the risk of heart disease. But, according to the NIH, these supplements likely fail in this task.

“Research indicates that omega-3 supplements don’t reduce the risk of heart disease,” the Institute wrote. However, people who eat seafood one to four times a week are less likely to die of this disease compared with people who rarely or never eat seafood.

Public health messages urging people to eat more seafood may have led to greater consumption of omega-3s from food, notes the NIH, but additional omega-3s via supplements may not have added benefits.

In addition, “More people are taking medicines that reduce the risk of heart attacks, such as statin drugs to treat high cholesterol. Omega-3s may not offer extra benefits beyond those of modern drug treatment,” they added.

In fact, for most conditions in which omega-3s have been studied, they show questionable or no benefit. Possible exceptions include the lowering of triglyceride levels, as well as relieving the symptoms of rheumatoid arthritis and slowing the progression of age-related macular degeneration.

Vitamin D

Many believe that supplementation of vitamin D can help prevent osteoporotic fractures. And, osteoporotic fractures are a big deal in the United States. A year after sustaining a fracture, many patients are unable to ambulate independently, with more than half needing assistance with activities of daily living, and with 20% to 30% dying.

So, does vitamin D supplementation work in populations at-risk for fracture? Not according to the US Preventive Services Task Force (USPSTF).  

In a recommendation statement published in JAMA, the Task Force wrote: “The USPSTF found inadequate evidence to determine the effects of vitamin D and calcium supplementation, alone or combined, on the incidence of fractures in men and premenopausal women.” Furthermore, the statement continued, evidence showed that daily supplementation with 400 IU or less of vitamin D combined with 1,000 mg or less of calcium has no effect on the incidence of fractures in community-dwelling, postmenopausal women.

In addition to providing no benefit, vitamin D plus calcium supplementation might increase the risk of developing kidney stones, noted the USPSTF. Notably, the risk is small and appears not to be caused by vitamin D supplementation alone.

But the news about vitamin D isn’t all bad. According to some research, vitamin D might be helpful in fighting dementia, heart disease, hypertension, and diabetes. Read more about this topic on MDLinx.

Vitamin C

Vitamin C is popular and found in most multivitamins. It is also available as a dietary supplement. Typically, vitamin C is available as ascorbic acid, but can also be found as sodium ascorbate, calcium ascorbate, other mineral ascorbates, and ascorbic acid with bioflavonoids.

Research has not distinguished any marked efficacy of one iteration of vitamin C over another. Moreover, vitamin C doesn’t seem to work for the prevention of various conditions, according to the NIH.

Although those who secure plenty of vitamin C by eating fruits and vegetables have a lower risk of developing lung, breast, and colon cancer, the intake of vitamin C supplements with or without antioxidants appears to offer no preventive benefit with regard to cancer, the NIH wrote. To boot, vitamin C supplementation may interfere with chemotherapy and radiotherapy cancer regimens; those receiving these treatments should consult with their oncologist before taking vitamin C or other antioxidant supplements, particularly in high doses.

Similarly, people who eat loads of fruits and vegetables also are at lower risk of heart disease, but supplementation fails to offer preventive health benefits. “Researchers believe that the antioxidant content of these foods might be partly responsible for this association because oxidative damage is a major cause of cardiovascular disease. However, scientists aren’t sure whether vitamin C itself, either from food or supplements, helps protect people from cardiovascular disease. It is also not clear whether vitamin C helps prevent cardiovascular disease from getting worse in people who already have it,” according to the NIH.

As for the common cold, vitamin C supplements may help only marginally. Studies show that for most of us, vitamin C supplements do not reduce the risk of getting the common cold. Once you have a cold, however, taking vitamin C supplements may slightly shorten the duration or severity of milder cold symptoms. Using vitamin C supplements after cold symptoms start does not appear to be helpful, notes the NIH.

In addition to providing few benefits with respect to many medical conditions, overdoing it with vitamin C supplementation can lead to diarrhea, stomach cramps, and nausea. Moreover, in those with hemochromatosis, vitamin C can exacerbate iron overload and lead to tissue damage.

Read more about vitamin C on MDLinx.

Vitamin E

Vitamin E possesses distinct antioxidant properties and is available in supplement form. In nature, vitamin E is available in eight forms: alpha-, beta-, gamma-, and delta-tocopherol and alpha-, beta-, gamma-, and delta-tocotrienol. In humans, only alpha-tocopherol is needed, and it’s this form that’s available in supplements.

According to the NIH, vitamin E supplements fail to proffer health benefits with respect to various health conditions. “[C]linical trials have not provided evidence that routine use of vitamin E supplements prevents cardiovascular disease or reduces its morbidity and mortality. However, participants in these studies have been largely middle-aged or elderly individuals with demonstrated heart disease or risk factors for heart disease,” the Institute wrote. 

The NIH also cited research that vitamin E supplementation may actually increase the risk of hemorrhagic stroke. Similarly, instead of lowering the risk for cancers, vitamin E supplementation may increase the risk of prostate cancer.

According to other data cited by the NIH, taking vitamin E supplements—either with or without other antioxidants—also is also ineffective in preventing age-related macular disease and cataracts, as well as slowing cognitive decline.

Read more about vitamin E and other vitamins that may play a role in immunity at MDLinx.

Bottom line

Despite their touted health benefits, many supplements fail to cut the mustard. At the least, these supplements are a waste of money; at most, their intake could result in unwanted adverse effects. Exhibit caution and refer to clinical guidelines when recommending supplements.

Click here to learn more about supplements that can do more harm than good, on MDLinx.

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