7 Popular Supplements With Potential Hidden Dangers

Healthy or risky? Here’s what you need to know about possible harmful effects before you pop that vitamin, mineral, or herbal pill.

When it comes to supplements, there’s so much talk about their potential benefits that it can be hard to separate fact from fiction. While it’s true that vitamins and minerals are essential to health, it’s not always true that taking them in pill, capsule, or powder form — especially in megadoses — is without risks.

For one thing, dietary supplements can sometimes interact with each other, as well as with over-the-counter (OTC) and prescription medication. In addition, unlike drugs, the U.S. Food & Drug Administration (FDA) is not authorized to review dietary supplements for safety and effectiveness before they are marketed. It’s up to manufacturers to ensure that their products do not contain contaminants or impurities, are properly labeled, and contain what they claim. In other words, the regulation of dietary supplements is much less strict than it is for prescription or OTC drugs.

Yet, according to a study published in October 2016 in the Journal of the American Medical Association, more than one-half of Americans take herbal or dietary supplements daily, making these products a booming industry with sales reaching $128 billion yearly worldwide, according to a report published in 2018 by the Nutrition Business Journal. More than 31 percent of those sales take place in the United States.

Used properly, supplements can improve your health and fill a nutritional void, but when used irresponsibly they can be ineffective or even harmful. For example, Tufts University research published April 9, 2019, in the journal Annals of Internal Medicine linked daily doses of more than 1,000 milligrams (mg) of calcium to a higher risk of death from cancer. Furthermore, the data showed that people who took adequate amounts of magnesium, zinc, and vitamins A and K had a lower risk of death.

Confused? National Institutes of Health (NIH) fact sheets can provide detailed information on the benefits and risks of individual vitamins and minerals, as well as herbal supplements.

Highlighted here are seven supplements that you should take carefully, if at all, depending on needs.

𝟭. 𝗩𝗶𝘁𝗮𝗺𝗶𝗻 𝗗: 𝗧𝗼𝗼 𝗠𝘂𝗰𝗵 𝗖𝗮𝗻 𝗛𝗮𝗿𝗺 𝗬𝗼𝘂𝗿 𝗞𝗶𝗱𝗻𝗲𝘆𝘀

Vitamin D promotes calcium absorption in the body, and getting enough is central to health and well-being, offering the promise of protecting bones and preventing bone diseases like osteoporosis. Supplemental vitamin D is popular because it’s difficult (if not impossible) to get enough from food. Also, as the Centers for Disease Control and Prevention (CDC) notes, our bodies make vitamin D when bare skin is exposed to sunlight, but increased time spent indoors and widespread use of sunblock has minimized the amount of vitamin D many of us get from sun exposure.

But enthusiasm for vitamin D supplements is outpacing the evidence. As it turns out, when healthy women take low doses of vitamin D (up to 400 international units, or IU) it does not necessarily prevent them from breaking bones, according to a U.S. Preventive Services Task Force report published in May 2013 in the journal Annals of Internal Medicine.

And taking high doses is not a good option. In healthy people, vitamin D blood levels higher than 100 nanograms per milliliter (ng/mL) can trigger extra calcium absorption — and lead to muscle pain, mood disorders, abdominal pain, and kidney stones, notes the Cleveland Clinic. It may also raise the risk of heart attack and stroke.

“More is not necessarily better when it comes to micronutrient supplements,” says Manson.

The outlook is different for women who are over age 71, deficient in vitamin D, live in institutions, or have dark skin pigmentation. For them, the National Academy of Medicine reports, vitamin D supplements prescribed by a doctor are beneficial. To achieve vitamin D recommendations — 600 IU per day for people 1 to 70 years old and 800 IU per day for individuals 71 or older — include whole foods, such as salmon, tuna, milk, mushrooms, and fortified cereals in your daily diet. You can also spend a brief time in the sun without sunblock — about 10 to 15 minutes a day, according to the NIH. 

𝟮. 𝗦𝘁. 𝗝𝗼𝗵𝗻’𝘀 𝗪𝗼𝗿𝘁: 𝗔𝘃𝗼𝗶𝗱 𝗗𝗿𝘂𝗴 𝗜𝗻𝘁𝗲𝗿𝗮𝗰𝘁𝗶𝗼𝗻𝘀

St. John’s wort is a plant used as a tea or in capsules to treat mild depression, anxiety, and sleep disorders. Small studies have shown St. John’s wort to be effective at treating mild depression. For example, a review published March 2017 in the Journal of Affective Disorders looked at of 27 clinical trials with a total of 3,808 patients and concluded that the herbal remedy worked as well as certain antidepressants at decreasing symptoms of mild to moderate depression.

But, says Denise Millstine, MD, an internist in the department of integrative medicine at Mayo Clinic in Phoenix, Arizona, “The biggest issue with St. John’s wort is its medication interactions.”

A study published in July 2014 in the Journal of Alternative and Complementary Medicine found that 28 percent of the time St. John’s wort was prescribed between 1993 and 2010, it was administered in dangerous combinations with antidepressant or anti-anxiety medication, statins, the blood-thinning drug warfarin, or oral contraceptives. For example, combining St. John’s wort with an antidepressant can cause serious complications, including a life-threatening increase in the brain chemical serotonin, according to the National Center for Complementary and Integrative Health. 

Taking St. John’s wort may also reduce the effectiveness of other medications — including birth control pills, chemotherapy, HIV or AIDS medication, and medicine to prevent organ rejection after a transplant. It’s important to read up on potential drug interactions and talk to your doctor before taking St. John’s wort.

𝟯. 𝗖𝗮𝗹𝗰𝗶𝘂𝗺: 𝗧𝗵𝗲 𝗘𝘅𝗰𝗲𝘀𝘀 𝗦𝗲𝘁𝘁𝗹𝗲𝘀 𝗶𝗻 𝗬𝗼𝘂𝗿 𝗔𝗿𝘁𝗲𝗿𝗶𝗲𝘀

Calcium is essential for strong bones and a healthy heart, but too much is not a good thing. In fact, an excess of calcium, which is described by the NIH as more than 2,500 mg per day for adults ages 19 to 50, and more than 2,000 mg per day for individuals 51 and over, can lead to problems.

According to the Cleveland Clinic, “Researchers believe that without adequate vitamin D to help absorb it, the extra calcium settles in the arteries instead of the bones.”

In addition, an analysis of 10 years of medical tests on more than 2,700 people in a federally funded heart disease study, published October 10, 2016, in the Journal of the American Heart Association, suggested that taking calcium supplements may increase plaque buildup in the aorta and other arteries. In contrast, a diet high in calcium-rich foods, such as dairy products and leafy greens, appeared to be protective.

The National Institutes of Health (NIH) recommends 1,000 mg of calcium a day for women ages 19 to 50, and 1,200 mg a day for women 51 and older. The recommendation for men ages 19 to 70 is 1,000 mg a day, and 1,200 mg a day for men 71 and older. According to the U.S. Department of Agriculture (USDA), 6 ounces of plain low-fat yogurt contains about 311 mg of calcium, a little less than one-third of the daily recommendations. Other good calcium sources include tofu, nonfat milk, cheese, fortified cereal, and juices.

𝟰. 𝗠𝘂𝗹𝘁𝗶𝘃𝗶𝘁𝗮𝗺𝗶𝗻𝘀 𝗮𝗻𝗱 𝗠𝘂𝗹𝘁𝗶𝗺𝗶𝗻𝗲𝗿𝗮𝗹𝘀: 𝗡𝗼𝘁 𝗮 𝗦𝘂𝗯𝘀𝘁𝗶𝘁𝘂𝘁𝗲 𝗳𝗼𝗿 𝗮 𝗛𝗲𝗮𝗹𝘁𝗵𝘆 𝗗𝗶𝗲𝘁

Think that a healthy lifestyle requires not just eating good-for-you foods, exercising, and getting enough sleep, but also taking a daily multivitamin-multimineral supplement? You may be surprised to learn that the jury’s still out on whether those supplements are truly helpful.

However, recent research has found benefits to taking multivitamins. For example, a study published August 9, 2017, in the journal Nutrients concluded that frequent use of multivitamin and mineral supplements helped prevent micronutrient shortfalls that might otherwise cause health problems.

For women of childbearing age, taking prenatal vitamins with folic acid is recommended by the American College of Obstetricians and Gynecologists to help prevent birth defects. Multivitamins might also be prescribed by your doctor if you have malabsorption syndrome, a condition in which the body does not properly absorb vitamins and minerals.

But for healthy people, Manson says, “a supplement can never be a substitute for a healthy diet." Remember, supplements are just that — designed to supplement a diet that may be deficient in required nutrients or as a natural remedy for a health condition.

𝟱. 𝗙𝗶𝘀𝗵 𝗢𝗶𝗹 𝗦𝘂𝗽𝗽𝗹𝗲𝗺𝗲𝗻𝘁𝘀: 𝗖𝗵𝗼𝗼𝘀𝗲 𝗙𝗶𝘀𝗵 𝗼𝗿 𝗙𝗹𝗮𝘅𝘀𝗲𝗲𝗱 𝗜𝗻𝘀𝘁𝗲𝗮𝗱

Rich in omega-3 fatty acids, fish oil has been touted as a means to reduce heart disease. However, more and more evidence shows that fish oil supplements have questionable heart benefits. A study published January 3, 2019, in The New England Journal of Medicine (NEJM) found that omega-3 fatty acid supplements did nothing to reduce heart attacks, strokes, or deaths from heart disease in middle-aged and older men and women without any known risk factors for cardiovascular disease. An earlier study, published in May 2013 in NEJM, looked at people at high risk for cardiovascular disease and also reported no benefit.

According to the NIH, omega-3 deficiency is “very rare in the United States.” Still, many people fail to consume enough omega-3s daily for optimal health. The best way to get adequate amounts is by eating a variety of foods that are rich in them, including:

  • Fish and other seafood, especially cold-water fatty fish, such as salmon, mackerel, tuna, herring, and sardines
  • Nuts and seeds, such as flaxseed, chia seeds, and walnuts
  • Plant oils, such as flaxseed oil, soybean oil, and canola oil
  • Fortified foods, such as certain brands of eggs, yogurt, juices, milk, and soy beverages 

𝟲. 𝗞𝗮𝘃𝗮: 𝗢𝘃𝗲𝗿𝘂𝘀𝗲 𝗖𝗮𝗻 𝗛𝗮𝗿𝗺 𝗬𝗼𝘂𝗿 𝗟𝗶𝘃𝗲𝗿

Kava is an herb that in concentrated forms has been used to treat general anxiety disorder with some success. An Australian study published online in 2015 in the journal Trials found that the South Pacific plant can be an effective alternative treatment to prescription medication for people diagnosed with generalized anxiety disorder (GAD). An earlier, smaller study, published in October 2013 in the Journal of Clinical Psychopharmacology, also showed that taking kava significantly reduced anxiety compared with a placebo in people with GAD.

However, taking too much kava, or taking it for too long, has been linked to serious liver damage, including hepatitis, cirrhosis, and liver failure. As a result, according to the NIH, the FDA has warned that people, especially those with liver disease or liver problems, or those who are taking drugs that can affect the liver, should talk to their healthcare practitioner before using kava. In addition, the National Center for Complementary and Integrative Health reports that heavy consumption of kava has been associated with heart problems and eye irritation.

A few countries, including France and Canada, have banned kava because of the risk it poses to the liver. But you can still buy it in the U.S. and online.

𝟳. 𝗦𝗼𝘆 𝗜𝘀𝗼𝗹𝗮𝘁𝗲: 𝗖𝗮𝗿𝗲𝗳𝘂𝗹 𝗪𝗶𝘁𝗵 𝘁𝗵𝗲 𝗘𝘀𝘁𝗿𝗼𝗴𝗲𝗻

Tofu, tempeh, and soy milk are all good sources of protein, fiber, and a number of minerals. Some women also take soy in supplement form because the plant contains estrogen-like compounds called isoflavones that may help relieve symptoms of menopause. However, concerns have been raised that the isoflavones in soy supplements may contribute to an increased risk of breast cancer.

The good news is that large-scale studies have not shown any increased breast cancer risk from eating whole soy foods, such as tofu and edamame, according to the Dana Farber Cancer Institute in Boston.

In fact, at least one study, published March 6, 2017, in the journal Cancer, which looked at 6,235 breast cancer survivors, linked eating the equivalent of one serving of soybeans a week to a 21 percent lower risk of death from all causes during the nearly 10-year follow-up period.

But not enough research has been done on soy protein isolate (SPI) — the powder formed by removing the protein from the rest of the plant — to know its effect on breast cancer risk, Millstine says. (In addition to supplements, SPI is often found in power bars, veggie burgers, and some soups, sauces, smoothies, and breakfast cereals.)

The bottom line: “If you’re concerned about breast cancer, stay away from soy supplements and soy-based protein,” Millstine advises. “Soy intake from foods has not been shown to be of concern though.”


Look at the label on your supplements and know which ingredients it contains. Furthermore, make sure you trust the brand you purchase is putting a safe dose of each ingredient into their formulation.

I’ve said this many times before — be wary of nutritional supplements that don’t list how much of each ingredient is contained in their formula. Many companies will mask their ingredient quantities by using terms such as “proprietary blend” on their product labels and website. 

If you’re taking a drug, it’s important you and your doctor know how much you’re taking. Nutritional supplements aren’t much different, particularly if you’re also taking prescription medications. With vitamins, minerals, and most of the more common herbal ingredients, studies have been conducted that look at the most beneficial dose for efficacy and safety.

At Trust Organix, we study research data to ensure our products are formulated using an effective and safe dose for each of our ingredients plus we always list the exact amount of each ingredient on our product labels. We believe our customers should know exactly what they’re getting when purchasing health supplements.

Trust Organix health supplements are made in a Good Manufacturing Practices (GMP) Certified facility and our facility is FDA Registered. Additionally, our manufacturing facility exceeds ASI Food Safety guidelines and our products are Certified Halal.

Know what you’re buying! Buy your nutritional supplements with security from Trust Organix.

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