April Fools’ Day may be over for this year, but there are still several opportunities to be fooled throughout the coming year. One common way Americans are being deceived lately is by the increasing fraudulent claims from the supplement world. Considering how common supplement use is, some experts are ringing alarm bells. Since Covid, supplement sales have exploded with roughly $45 billion in annual sales in the U.S., according to Grand View Research, a U.S.-based research firm. Penn State Health News estimated approximately 59 million Americans use some type of vitamins or supplements regularly, spending an average of $510 annually with supplement use estimated at over 12% of all adults including those over age 60. Supplements are everywhere: Gummies, protein shakes and other myriad supplements that increase a body’s supply of critical vitamins and minerals.
To see why caution is advised, consider these examples of current popular claims extolling supplements’ power to enhance natural human immunity. With the rise of flu, Covid, and other respiratory conditions, marketers are aggressively promoting the idea that supplements can boost one’s immune system.
But can they really? Nutrition Action, a popular research-based periodical (available at the Huntley library) asks just that question in the April 2025 issue: “Can supplements ward off a cold, the flu, or Covid?” According to the research cited, let’s see how effective these four supplements are: Vitamin C, Zinc, Elderberry, and Vitamin D.
First up – Vitamin C
We know that foods rich in vitamin C can contribute to a stronger immune system by supporting white blood cell function and acting as an antioxidant, according to the Cleveland Clinic Health Essentials and the Academy of Nutrition and Dietetics. But how does a supplement (not a whole orange or grapefruit) do in building stronger immunity? It seems taking the vitamin out of the whole food it’s packaged in diminishes that immune-boosting ability. Despite the claims, in 24 trials Vitamin C supplement’s ability to treat cold symptoms was not evident. In 7 other studies cold sufferers did not have less severe illness and in only 1 study did the cold symptoms improve symptoms and even in that study symptoms were only shortened by half a day. Bottom-line: Inconclusive evidence of effectiveness.
What about Zinc?
Again, getting adequate zinc in your diet through foods can help your immune system, because a zinc deficiency can weaken your immune system. However, research shows zinc won’t ward off a cold. However, once you get a cold, there is evidence that sucking on zinc lozenges may prevent viruses from spreading, shortening your cold. Not all studies show this effect, however, and one of the best designed studies demonstrated no effect. For Covid, the zinc supplement was equally ineffective in shortening symptoms. Bottom line: Zinc lozenges could shorten duration but not lessen symptoms for colds and studies could not demonstrate any effect for Covid.
Elderberry to the rescue?
Despite the claims, there was no convincing evidence that elderberry supplements could prevent cold and flu. Bottom line There were few non-industry-funded well-designed studies and even these showed no difference in prevention or length of flu symptoms.
And Vitamin D?
37 randomized trials involving 46,000 showed that Vitamin D could help in lowering the risk of a cold or flu but only by 8 percent. For Covid most evidence showed no benefit from taking Vitamin D supplements. Bottom line: Slight benefit in preventing cold or flu, no benefit for Covid prevention or symptoms.
So should the public avoid all supplement use?
The effectiveness of supplement use in the above example was either absent or minimal, which seems to highlight the need to carefully consider the exaggerated claims of supplement marketers. When considering the question of need for supplements, Dr. Matthew Silvis, vice chair of clinical operations for Penn State Health Family and Community Medicine summarized when considering the question of need for supplements, “The broad answer is most people don’t need them, despite the multibillion-dollar industry that the vitamin industry is. If you have a well-balanced diet and you’re able to eat nutritious foods ― fruits, vegetables, etc. ― you don’t need a multivitamin or a supplement.”
However, the public needn’t avoid all supplements. Dr. Silvas continued:” … there are populations of individuals who do need to consider a multivitamin or a supplement. And that is individualized.”
Next month this health news report will explore instances when supplements might be advisable and will conclude with resources so readers can obtain reliable information about supplements and five strategies consumers can use to protect themselves – so they won’t get fooled by fraudulent supplement claims.
