Can you overdose on vitamins?

Yes, you can take too many vitamins and they can make you sick

Too much of vitamins A, D, E, and K (which are fat-soluble) can build up in the body and cause serious health problems, including liver damage, kidney stones, and blood clotting irregularities. Excess iron and calcium can also make it harder for the body to absorb other needed nutrients.

Vitamin D supplement pills are linked to rising cases of vitamin D toxicity in the US

Vitamin D deficiency is common. But taking Vitamin D supplements in doses exceeding 4,000 IU/day (a measurement of vitamin biological activity) for prolonged periods can raise bodily concentrations of this vitamin to dangerous values. US National Poison Data indicates that the annual average of vitamin D poisonings from 2000-05 was 196, but this rose by 1,600% to 4,535 per year for the period of 2005-11.

Most adults don't need a daily vitamin, and it won't extend your life

A 20-year study by the National Cancer Institute involving almost 400,000 people found that daily multivitamins did not help people live longer. In some cases, these vitamins also increased the risk of death. Although some subpopulations—such as those with documented vitamin deficiencies and pregnant individuals—should take vitamins, daily multivitamins should not be taken uniformly by adults. Instead, patients should discuss vitamins with their clinicians and consider baseline vitamin testing before starting vitamin regimens.

Gummy vitamins have candy-level sugar—and that sweetness is linked to overdoses

A typical gummy vitamin contains about the same amount of sugar in a single serving as one Sour Patch candy. It's linked to the increase in pediatric overdoses for products including multivitamins and melatonin. Gummy formulations also degrade quickly, so they often include much higher levels of the product in each serving than the label advertises—boosting overdose risks due to this unchecked variability. (Some users may experience a paywall.)

Do you need a multivitamin?

In 2013, several researchers declared multivitamins dead, stating that so-called supplements had no clear benefits and might be harmful. But the science isn't so clear-cut. This article explores the question of who would benefit from...

Humans need vitamins, but research is mixed on taking supplements

When an organism needs an organic molecule to survive, but cannot synthesize enough of it itself, that molecule is called a vitamin. Typically, we consume vitamins through food, but many resort to supplements—a common and mostly unregulated practice.

Humans need higher levels of water-soluble vitamins that easily pass through the body

There are two types of vitamins: lipid soluble and water-soluble. Water-soluble vitamins like B vitamins and vitamin C are in the watery parts of fruits and easily pass through the human body before being taken up by the bloodstream or exiting your body. But lipid (fat) soluble vitamins must be absorbed through the intestinal wall, carried by proteins, and then may be stored in the liver and other body parts—meaning there is greater risk of overdosing.

Supplements are only typically recommended for those with a proven deficiency

Blood tests and other dietary screening tools by clinicians and nutritionists can indicate whether someone is deficient in needed vitamins or minerals, and those results can then lead to a personalized care plan that may include supplements. Supplements can negatively interact with certain medications, so it's important to speak with your doctor about supplements before taking them.

Supplements often have issues with impurities, toxins, and inaccurate labels

Consumer Reports' tests of more than 20 supplement powders and shakes in 2025 found that more than two-thirds of them contain unsafe levels of lead. Some contained 10 times the amount of lead that's considered acceptable to ingest in a day. The levels they found, in some cases, were even higher than when they tested the products 15 years earlier.

Up to 400 milligrams of caffeine a day is considered safe

Small, frequent doses can be more effective than large amounts, though caffeine can raise blood pressure and heart rate, especially in people with hypertension. While low doses of caffeine may help with depression by stimulating dopamine, excessive caffeine, particularly from energy drinks, can lead to anxiety and heart issues.

Symptoms of DNA loss may mimic those seen in mushroom poisoning or chemotherapy

Although no organism has ever lost all its DNA, the destroying angel mushroom contains amatoxin, which disrupts DNA transcription and is known to cause death via liver and kidney failure in three days. Doxorubicin, which tangles DNA to disrupt cellular replication, compromises a person's immune system.

Overuse of opioids can lead to hypersensitivity to pain

Opioid misuse can lead opioid-induced hyperalgesia, where the body becomes increasingly sensitive to pain. The body produces its own opioids as a way to temporarily block pain signals. When met with external opioid use, the body ratchets up pain sensitivity to ensure it senses the pain necessary to trigger its own response.

What happens when the gut microbiome is out of whack?

An imbalance in gut microbiome flora can lead to a condition known as dysbiosis. This condition is typically characterized by a drop in microbiota diversity and an increase in harmful unicellular and acellular organisms, such as viruses, that can negatively impact the host's immune system and overall health. Genetics, infections, dietary choices, antibiotics, food additives, artificial sweeteners, and other lifestyle and environmental factors can cause dysbiosis.

'Genericide:' Learn how too much brand awareness can hurt a company's trademark

When a brand becomes so popular that consumers regularly call the product by the brand name like a noun or verb, that trademark becomes generic because consumers no longer associate a specific brand with a certain product. A generic product can hurt a company's right to trademark or even cause companies to lose it. (Some users may experience a paywall.)

Accidental ingestion of batteries can be life-threatening

Tissue in the body can serve as a circuit path between the anode and cathode of a battery, resulting in electrical burns and gradual tissue erosion. Stomach acid can corrode a battery and cause its toxic contents to leak, making a person sick. Batteries for internal use, such as in pacemakers, require special designs.

Pooping or puking out pathogens is sometimes recommended with food poisoning

Sometimes stopping food poisoning-linked diarrhea with over-the-counter medications is a bad idea because it may prolong illness. Doctors can advise you if your diarrhea or vomiting is severe about what medications to take and when, but generally doctors recommend trying to stay hydrated during a bout of food poisoning and letting the body naturally remove pathogens from the body via vomiting or diarrhea, as needed.

Learn about ionizing radiation and see the most radioactive places on Earth

The average person is exposed to radiation every day, though most of it is either harmless non-ionizing radiation or ionizing radiation at doses too small to significantly affect an individual. The highest doses of ionizing radiation are received by smokers due to the radioactive polonium and radioactive lead in tobacco products.

Fantasy sports can have adverse health effects

Experts warn that fantasy sports, including fantasy football, can encourage obsessive use because they offer hits of dopamine. Daily fantasy games, which function more like gambling, are especially problematic.

What happens to your brain when you burn out?

You've probably heard of burnout, also known as the feeling of exhaustion that happens after a long period of being overwhelmed or stressed. It's often associated with work and careers, but other parts of life, like parenting, can cause burnout, too. Scientists are figuring out what happens, biochemically speaking, in the brain when burnout hits—and spoiler alert, it includes a neurotransmitter called glutamate. Watch this video to learn more.

Memory disorders disrupt the brain's ability to make, store, or recall memories

These disorders stem from reversible issues like vitamin deficiencies or irreversible causes such as stroke or dementia. Only one type of dementia—familial Alzheimer’s disease—is directly inherited and accounts for about 20% of Alzheimer’s cases.

Prince died in 2016 from an accidental fentanyl overdose

The music legend was found dead in an elevator at his Paisley Park residence on April 21, 2016. The cause of death was an accidental overdose from taking pills he believed to be Vicodin, but were actually counterfeit pills laced with fentanyl. Law enforcement was unable to determine who provided him with those pills. He was 57 at the time of his death.

How to avoid a 'bad trip' advice includes relaxing your mind if you experience scary things and not fighting the feeling

In this video, Michael Pollan, author of "This Is Your Mind On Plants," underscores the gaps in existing understanding about the substances and recommends only taking guided experiences, for safety and help. He tackles how psychedelics work, explains microdosing and psychedelic risks, how the substances could be used to treat addiction, and the history of psychedelic stigma.

In 2012, a virus that causes HFMD may have killed dozens of kids in Asia

More than 50 young children in Cambodia died in spring 2012 for unknown reasons, but laboratory testing of samples available from a limited number of those children came back positive for Enterovirus 71. That virus, which can cause HFMD, is known to cause severe complications among some people who contract the disease. But health officials concluded that poor baseline health and then incorrect treatment using steroids helped exacerbate their condition, helping lead to the deaths.

Understanding vaccine side effects

A vaccine is a medical intervention, and as with any medical intervention, may have side effects. This article discusses side effects and adverse events related to vaccination.

See examples of hyperaccumulators, the plants that can harvest heavy metals

These ideal species for phytoremediation possess biochemistry that allows them to absorb and store these elements without being poisoned by their accumulation. Pycnandra acuminata, one such plant, has blue-green sap due to an abundance of nickel, which it captures from the nickel-rich soil in which it grows.

At the beginning of the 20th century, a group of young men ate standard American food—replete with food additives like borax and formaldehyde—as part of government research to better understand food safety.

Doctors differentiate between a phobia and fear by asking patients whether their fear interferes with their day-to-day activities.

Poison ivy's rash-causing compound is found in the plant's roots, stem, and leaves—so coming into contact with any part of the plant can lead to rashes for the 85% of people who are allergic to it.

Watch how viruses like Ebola can spill over from animals to humans—and vice-versa.

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

Discover the catastrophic consequences of a failure of the US electrical grid—something that is more likely than many Americans think.

Studies suggest when you sleep is as important as how much you get, and syncing with your circadian rhythms may lead to less fatigue and improved long-term health outcomes

Indefinite cloning of some endangered species may not sustain their longevity because cloning success rates decrease as genetic mutations accumulate.

Volcanoes 'die' when their supply of magma runs out, if they are shifted away from their underlying magma reservoir, or if they get clogged by collapsing or their magma cooling back into rock.

Hookworm infection, though risky, may help fight certain autoimmune conditions by tamping down the immune system's inflammatory response.

Telehealth demand for GLP-1s for weight loss is booming as consumers seek easier access.

The use of fungi to detoxify land and water—a process known as mycoremediation—has been used to clean up natural resources affected by the 2025 California wildfires.

Listen to an in-depth conversation on the links between Parkinson's disease and herbicide exposure and the challenging pace of scientific investigation.

Firework or sparkler burns, even if they cover a relatively small area of skin, can significantly affect our range of motion.

Bone marrow (soft tissue found inside certain bones) generates roughly 500 billion new blood cells each day

US consumers collectively owe more than $1T to credit card companies—almost as much as they owe in auto loans.

The power and influence of the American presidency have expanded significantly over time—far beyond what the founders envisioned.

Tattoos remain visible on your skin thanks to immune cells called macrophages

A pickleball's loud 'pop' sound can reach 120 decibels, which is equivalent to a hammer hitting a nail

Coral reefs get their colors from zooxanthellae—microorganisms that line corals' digestive tracts and provide them with sugars in exchange for a home within this protective tissue.

Alzheimer's can lead to brain shrinkage, with an average of around 2% of volume reduction per year

NBA superstar Victor Wembanyama spent the 2025 summer training with monks in central China to enhance his body and mind.

A Yale student wrote a profound essay about the consulting industry's influence on elite college students that was published in a book of her writing after she died in a post-graduation car accident.

Pure water does not conduct electricity because this flow of energy requires the movement of charged particles, and water is a neutral molecule.

Use this tool to calculate the dollar value of your parental mental load, from meal planning to coordinating after-school care, then see resources that help generate solutions.