Did you know that around 23,000 emergency room visits a year are the result of reactions to dietary supplements? Or that spending on dietary supplements tops $30 billion (2011 figure)?
What are dietary supplements anyway?
The Food and Drug Administration defines dietary supplements as products that you take to add to the nutritional value of your diet. They can included vitamins, minerals, botanicals, herbs and even amino acids.
What do you know about them? Are dietary supplements safe to take?
Drug Interactions with Dietary Supplements
A recent study (March 2016) published in JAMA, sheds light on that question.
The study involved interviewing over 2000 adults and inspecting their medications twice, first in 2004-2006 and again in 2010-2011. Researchers then checked on dangerous dietary supplement and prescribed medication interactions.
The number of dietary supplements people take had increased significantly in the years between interviews. And with that increase came a significant increase in the number of adults at risk of interactions between the dietary supplements they take and the medications that had been prescribed for them. From the data, researchers concluded that 15% of older adults are potentially at risk for a major life threatening dietary supplement to prescribed medication interaction.
Why do people take dietary supplements like multivitamins?
The majority of the dietary supplements that are taken are multivitamin-minerals (MVMs). Seventy-seven percent of people taking MVMs are taking them, not because they have been prescribed by their physician, but because they believe there are benefits. The survey indicated that people believe that MVMs improve (45%) or maintain (33%) their overall health. A recent survey finds that the majority of supplement users would continue using them, even if scientific evidence indicated the supplements were ineffective.
So what is the evidence? Are MVMs and other dietary supplements safe and effective? What are the myths about dietary supplements that need clarification?
Myth Busting Dietary Supplements
The FDA tests dietary supplements the same way they do prescribed and non-prescribed (over-the-counter drugs (medications.)
Dietary supplements are not covered by the same regulations as pharmaceuticals. The FDA reviews pharmaceutical medications for safety and effectiveness prior to ever being put on the market for consumers. Unfortunately, the FDA is not allowed to review dietary supplements before they are marketed to consumers. Instead the law states that it can only review for safety and effectiveness after the supplements are on the market.
Dietary supplements are generally reviewed only after complaints are made about them by consumers. Only recently have manufacturers had to share the complaints they receive about supplements from consumers with the FDA.
“All Natural” is safe.
Many supplements state that they are “all natural.” Does this mean they are safe?
In a study published in BMC Medicine, researchers used DNA testing to determine what was in 44 herbal products from 12 different companies. They found that 59% contained DNA from plants not
listed on the label. Contaminants and fillers were found in 10 of the 12 companies’ products.
Natural supplements like herbals or botanicals can contain any parts of the plants-roots, stems, leaves or flowers. According to the American Cancer Society, the roots of dandelions are a laxative and the leaves contain a diuretic (makes you urinate). If the product contains all of the dandelion, you will get a combination of experiences that you might not have wanted.
The FDA specifically states that “Be aware that the term natural doesn’t always means safe.”
More is better.
You should take megadoses of vitamins and/or minerals.
The FDA again specifically warns
“The following actions could lead to harmful – even life-threatening – consequences…[from]
Taking too much of some supplements, such as vitamin A, vitamin D, or iron.”
A review [in the Journal of the National Cancer Institute (2012)] of randomized control trials of vitamins and minerals is like reading a list of broken promises. Here are just a few examples of results: β-carotene (which converts to Vitamin A in the body) did not prevent recurrences of non-melanoma skin cancer, α-tocopherol (a Vitamin E precursor) and β-carotene did not prevent lung cancer, Vitamins C, A and E given together or in combination, did not prevent stomach or intestinal cancers. The list goes on and on.
Additionally the review included studies in which antioxidants actually increased the risk of cancers.
A caveat to the review of these many randomized control trials was that the exposure to the vitamin and or mineral was not long-term. Even so, there is value in knowing if there were an increased risk of cancer (in the short-term) from taking too many supplements.
What Should You Do?
First, if you are undergoing chemotherapy or radiation therapy, the American Cancer Society warns that dietary supplements can increase skin sensitivity and can interact with your treatments. You should share your list of vitamins or supplements with your oncologist.
Second, everyone should let their physician know of any supplements or vitamins or multivitamin-minerals that they take. Ask your pharmacist if there are any dietary supplement-medication interactions.
Third, the FDA provides warnings about products containing dangerous substances. Consult the FDA’s website. For example, the FDA warns consumers to avoid products that contain DMAA or methylhexanamine or geranium extract.
Fourth, when searching for information about supplements, do not go to commercial (.com) sites. Instead choose .gov sites like the FDA or NIH websites.
Fifth, the FDA states that you should avoid taking megadoses of supplements.
Sixth, report any adverse experiences you have to your doctor and to the FDA.
Finally, perhaps the best advice is to be sure that you are taking vitamins and supplements that your physician prescribes for you. If your physician tells you to discontinue using MVMs, stop taking them.
And stay safe.
Consumer Reports is recommending supplements that are USP certified yet USP was one of 11 labs the FDA contacted about DMAA in some of their products. How does that make them appropriate to be the certifying authority?
Karen, Thank you so much for the correction! I truly appreciate this catch. Removing this information. Kathleen
I take vitamin B complex
I think a certain amount of common sense applies here. Vitamins aren’t miracle drugs, nor are they going to prevent cancer or serious illness. They should be regarded as supplements only, and as additions to good diet. I’ve read of studies that suggest the only really valuable vitamin that needs to be taken (unless you’ve had a blood test and your doctor tells you that something like iron or calcium would be beneficial) would be Vitamin D, because most of us don’t get the required 10 minutes of sunlight that we need, especially since countries like Australia have reported high incidences of skin cancers. I think what you’ve said here is the safest way, and to consult your pharmacist about any supplement you wish to take, so they can make sure you aren’t doubling up if you already take a supplement through prescription.
Thank you for your comment. Kathleen
The power of supplements comes from history – pellagra, rickets, scurvy all directly linked to vitamin deficiencies, and lets not forget iodine and the thyroid. Problem is in trust of the current products, of which I have very little. Congress is the handmaiden of the supplement industries, hence no standardization and very little support for well designed studies. Rhodiola [depression and anxiety disorders] and cinnamon [type 2 diabetes] are two examples that show promise, but the literature comes mostly from other countries and manufacturers lie with impunity regarding capsule contents.
Thanks John for adding to this conversation. Kathleen