Food supplements can make you sick

New estimates find that some types have been sending thousands to the hospital each year — including teens

food supplements

Food supplements come in many forms and colors. And while many may look like medicines, they are not tested for safety and reliability as medicines must be.


Doctors say eating a well-balanced diet is the best way to get the nutrients your body needs. People who think they may need a little extra help often reach for food supplements. These are diet aids, such as vitamins, herbal extracts and fish oil. The companies that sell them suggest they’ll make people healthier. But scientists warn that some of these products actually can make people ill.

Drug stores, groceries and health food shops all sell these products. They’re known as supplements because they are not strictly needed for health. They just supplement — or add to — what people already eat.

They might contain nutrients that are otherwise available from foods. Or they might provide plant-derived materials that work in the same way that drugs do. This might be to boost immunity, increase metabolism (how the body uses energy) or improve how organs of the body work. The caffeine pills that people take to stay awake on long drives are one example of supplements. So are the zinc-based lozenges that people take to fight colds.

Most of these diet aids just provide more of something that is already in the diet. As such, these supplements are supposed to be as safe as food.

Yet each year, a new study finds, food supplements send more than 23,000 people across the United States to emergency rooms (ERs). Each patient had suffered some sort of bad reaction. Doctors refer to such reactions as adverse events. Some people developed chest pains or heart palpitations — a feeling that the heart is beating too fast or hard. Others got headaches or felt dizzy. Still others might have suffered stomach pains, nausea or vomiting.

The study tallying these reactions to food supplements appeared October 15 in the New England Journal of Medicine.

Unexpected number of teens and young adults affected

For the study, researchers collected 10 years of data. These came from the ERs at 63 U.S. hospitals. Supplements had sickened 3,667 of these ER patients, they found. Then the researchers used statistics — various math techniques — to scale up how many times this likely happened if all U.S. hospitals had experienced a similar trend.

Supplements send thousands of people in the United States to emergency rooms every year, a new study found. MJFelt/iStockphoto
The authors were comfortable analyzing these data and making these extrapolations to other hospitals. They all work at the Centers for Disease Control and Prevention (CDC) in Atlanta, Ga., or for the U.S. Food and Drug Administration (FDA) in Washington, D.C. These are government agencies. CDC scientists and doctors make sure Americans receive safe, high-quality health care. The FDA, as its name implies, regulates the safety of food and drugs. For instance, it requires that prescription drugs and over-the-counter medicines (like cough syrups and aspirin) must be tested to show that they are safe and effective. Without tests that show that, FDA won’t let manufacturers sell these products.

Dietary supplements are considered neither foods nor drugs. So for a long while, no government agency had control over their safety or any claims made by the products’ makers. Then, in 1994, Congress wrote a law that ordered FDA to treat supplements like a special kind of food. Back then, FDA said it would assume that supplements are safe enough to sell without going through safety tests. And companies that created new supplements would only have to give FDA data showing why these products were likely to be safe.

The only statement a supplement maker could not make is that its product would cure a disease or condition. That would instantly turn the product into a “drug.” Then, as with other drugs, it would now need to go through strict testing and government controls.

healthy dinner
Doctors say that the best way to get nutrients is to eat a balanced diet with plenty of fruits and vegetables. bhofack2/iStockphoto
Andrew Geller is a CDC physician who led the new study. His team was concerned that supplements were not as safe as had been assumed. Why? In the past, he notes, “FDA has recalled supplements that contained unapproved ingredients or were contaminated.”(A recall is when a company must take back a product from stores, hospitals or consumers, usually because of problems with its safety or reliability.) “We didn’t know how many [other types of supplements] caused problems,” Geller says.

So his team reviewed the hospital data. They paid special attention to how old patients were, their symptoms and what supplements they had taken. Then the scientists used data from the studied hospitals to estimate what might be occurring nationally. Adverse events, they found, were not occurring just in older or unhealthy people. Young people were at risk, too.

“Adverse reactions to drugs are usually more common in older people,” noted Geller. “It was surprising,” he said, that many adverse reactions to supplements showed up in young people. After all, he notes, these are the people one would expect to be healthiest.

About 11 in every 100 adverse reactions occurred in people between the ages of 5 and 19. Across the United States, that would translate to more than 2,500 ER visits every year by kids and teens. Another 28 out of every 100 adverse events occurred in young adults, aged 20 to 34. That would translate to nearly 6,500 more ER visits yearly. Heart symptoms, such as chest pain and heart palpitations, were the most common effects among young adults.

Not all supplements equally risky

More than half of all side effects that sent people under age 35 to the hospital came from two types of supplements: weight-loss aids and energy boosters.

Weight-loss products come in many forms. They include pills, bars, liquids and powdered-drink mixes. There is no standard formula that all brands share. There also is no consistent list of safe ingredients.

vitamin c
The label on this bottle of vitamin C tablets notes that the evidence that this supplement reduces cancer risk is not conclusive. If a manufacturer were to make a claim that a product reduces cancer risk, that product would be regulated as a drug, not a supplement. Roel Smart/iStockphoto
One popular brand of these products, Hydroxycut, includes supplements containing plant-based stimulants such as green-coffee-bean extract and caffeine. Those chemicals can rev up the body’s metabolism — how fast it burns energy. Burn enough and people should lose weight.

But in 2009, FDA ordered Hydroxycut to recall many of its products. Their use had been linked to 23 cases of liver damage. In one case, a 19-year-old boy died.

In a 2013 survey of U.S. high school students, the CDC found that more than 6 out of every 100 high school girls reported taking diet aids without first talking to a doctor. If that trend holds nationally, it would equal roughly 500,000 adolescent girls.

Ruth Milanaik is a pediatrician at Cohen Children’s Medical Center in Lake Success, N.Y. She worries about how diet aids affect teenage bodies. For example, she says Hydroxycut “raises your core body temperature to speed up your metabolism. But teens are growing fast already,” she notes. “So making your system run faster can be harmful.”

The company that makes these diet aids says its products are now safe. Still, the products’ labels say these supplements should not be used by anyone under age 18.

Energy supplements also can contain a broad mix of ingredients. These can include caffeine, herbs that produce caffeine-like effects, vitamins and enzymes that are already in our bodies. Some also contain a lot of sugar, especially drinks and those supplements that come in the form of a snack bar.

Some users have complained to the FDA about problems they claim such energy supplements have caused them. Common symptoms include chest pain, the feeling of a racing heart and dizziness. In 2013, the American Medical Association called for a ban on advertising energy drinks to people under age 18 if those products contain “massive and excessive amounts of caffeine.”

These products likely contain stimulants, says the CDC’s Geller. “Symptoms like heart racing and chest pain are very similar to what you see in kids who have taken too much caffeine or … Ritalin.” That last drug, he notes, is a powerful stimulant used to treat ADHD (attention-deficit hyperactivity disorder).

Bulking up?

Pediatricians also worry about body-building supplements. These products promise to help users build muscle. That’s a common goal among teens who play sports, especially games where size is important, such as football.

One of the most popular sports supplements is creatine (KREE-uh-teen). The body already produces some creatine. In muscles, the compound helps produce a chemical called ATP, or adenosine triphosphate (Ah-DEN-oh-seen Try-FOS-fate). ATP carries and releases chemical energy that the body uses for many tasks. One example: ATP provides the energy to power muscle contractions during activities such as lifting weights.

protein supplements
Some supplements, such as creatine, are advertised to athletes and body-builders. But doctors worry that they may not be safe for anyone under age 18. David van der Mark/Flickr (CC-BY-SA 2.0)
“The more muscle your body has, the more creatine it makes,” says Milanaik. “But if you don’t have a lot of muscle mass yet and you take creatine, your body will try to get rid of it.” It would excrete the chemical as a waste. And in the process, she says, “That could damage your liver or kidneys.”

Milanaik led three recent studies in which college students posed as 15-year-olds. They called hundreds of health-food stores and pretended to shop for supplements. Girls asked about weight-loss supplements, including Hydroxycut. Boys said they were looking for creatine and products containing the hormone testosterone, which also supports muscle growth.

None of these products are recommended for users under age 18. But many sales clerks recommended them, or were willing to sell them to 15-year-olds, when the callers asked. These studies will be submitted to medical journals within the next few months.

“It’s a lesson that teens need to do their own research,” Milanaik now says. “Warning labels are there for a reason. Just because something comes from a vitamin shop or health food store doesn’t mean it’s good for you.”

Power Words

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adenosine triphosphate (ATP)    A complex molecule that provides most of the energy for activities in cells.

adolescence    A transitional stage of physical and psychological development that begins at the onset of puberty, typically between the ages of 11 and 13, and ends with adulthood.

adverse event     A term U.S. government regulators and doctors use to describe undesirable effects associated with taking a drug or supplement.

attention deficit hyperactivity disorder (ADHD)    This is a disorder characterized by not being able to focus or pay attention, being physically overactive, not being able to control behavior, or a combination of these.

caffeine    A stimulant, which activates the nervous system and heart. The leaves, seeds and fruits of many plants contain caffeine. In coffee plants and tea bushes, caffeine acts as a natural pesticide. It will kill or harm insects that attempt to dine on the plant. Caffeine is also toxic to some types of plants, bacteria — even frogs and dogs.

Centers for Disease Control and Prevention, or CDC    An agency of the U.S. Department of Health and Human Services, CDC is charged with protecting public health and safety by working to control and prevent disease, injury and disabilities. It does this by investigating disease outbreaks, tracking exposures by Americans to infections and toxic chemicals, and regularly surveying diet and other habits among a representative cross-section of all Americans.

chemical    A substance formed from two or more atoms that unite (become bonded together) in a fixed proportion and structure. For example, water is a chemical made of two hydrogen atoms bonded to one oxygen atom. Its chemical symbol is H2O. Chemical can also be an adjective that describes properties of materials that are the result of various reactions between different compounds.

creatine    A nitrogen-based compound made naturally by animals with backbones. It helps their bodies supply energy to cells, especially the making up muscle.

dietary supplement    A broad class of products that people use to promote or maintain health, or for other purposes such as boosting energy. Includes vitamins, minerals, herbal products, amino acids, enzymes and many other types of products. Supplements are sold without prescriptions, and are not required to be tested for safety or effectiveness before they are marketed.

enzyme    Molecules made by living things to speed up chemical reactions.

excrete  To remove waste products from the body, such as in the urine.

Food and Drug Administration (or FDA)    A part of the U.S. Department of Health and Human Services, FDA is charged with overseeing the safety of many products. For instance, it is responsible for making sure drugs are properly labeled, safe and effective; that cosmetics and food supplements are safe and properly labeled; and that tobacco products are regulated.

hormone    (in zoology and medicine) A chemical produced in a gland and then carried in the bloodstream to another part of the body. Hormones control many important body activities, such as growth. Hormones act by triggering or regulating chemical reactions in the body. 

immunity    The ability of an organism to resist a particular infection or poison by producing and releasing special protective cells.

kidney    Each in a pair of organs in mammals that filters blood and produces urine.

liver   An organ of the body of animals with backbones that performs a number of important functions. It can store fat and sugar as energy, breakdown harmful substances for excretion by the body, and secrete bile, a greenish fluid released into the gut, where it helps digest fats and neutralize acids.

metabolism    The set of life-sustaining chemical reactions that take place inside cells and bigger structures, such as organs. These reactions enable organisms to grow, reproduce, move and otherwise respond to their environments.

molecule  An electrically neutral group of atoms that represents the smallest possible amount of a chemical compound. Molecules can be made of single types of atoms or of different types. For example, the oxygen in the air is made of two oxygen atoms (O2), but water is made of two hydrogen atoms and one oxygen atom (H2O).

nutrient    Substances in food that provide nourishment humans and animals need to survive.

palpitations    A rapid heartbeat that draws attention to itself because of its pace, strength or uneven rhythm. It may be triggered by stress, muscle exertion or disease.

pediatrics   A field of medicine that has to do with children and especially child health. A doctor who works in this field is known as a pediatrician.

proteins    Compounds made from one or more long chains of amino acids. Proteins are an essential part of all living organisms. They form the basis of living cells, muscle and tissues; they also do the work inside of cells. The hemoglobin in blood and the antibodies that attempt to fight infections are among the better-known, stand-alone proteins.Medicines frequently work by latching onto proteins.

regulate    (n. regulation) To control with actions or by enforcement of laws. Governments write rules and regulations — laws — that are enforced by police and the courts.

ritalin    A drug that stimulates the central nervous system and is used to treat attention deficit hyperactivity disorder (ADHD) and related diseases.

statistics    The practice or science of collecting and analyzing numerical data in large quantities and interpreting their meaning. Much of this work involves reducing errors that might be attributable to random variation. A professional who works in this field is called a statistician.

stimulant     A substance that causes temporary improvements in either mental or physical function or both. Caffeine is a mild stimulant that for a short while enhances alertness and helps fight drowsiness. Other stimulants, including some drugs, have stronger or longer-lasting effects.

supplement   (verb) To add to something. (in nutrition) Something taken in pill or liquid form — often a vitamin or mineral — to improve the diet. For instance, it may provide more of some nutrient that is believed to benefit health.

testosterone    Although known as male sex hormone, females make this reproductive hormone as well (generally in smaller quantities). It gets its name from a combination of testis (the primary organ that makes it in males) and sterol, a term for some hormones. High concentrations of this hormone contribute to the greater size, musculature and aggressiveness typical of the males in many species (including humans).

vitamin    Any of a group of chemicals that are essential for normal growth and nutrition and are required in small quantities in the diet because they cannot be made by the body.

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