It's a hot topic in the debate about viruses and immunity. While vitamins can be a healthy habit, expert sources share important guidance.
Yes, It’s Possible To Overdose on Vitamins—a Family Doctor Explains
Published on Mar. 24, 2025
According to the Cleveland Clinic, more than 129 million American adults take a daily vitamin. It’s generally a healthy practice, especially as grocery prices drive many Americans to squeeze as many nutrients into the diet in a thrifty way. It’s also understandable why vitamins are so widely discussed, as an optimized immune system seems as important as ever—on Friday, the CDC reported that 18 U.S. states have reported cases of measles, which virology experts have stated is the most contagious virus known to humankind with one case’s transmission causing a further 12 to 14 cases.
Even so, says trained family physician Dr. Paricia Varacallo, DO, with vitamins intended to protect immunity: “It’s important to remember that more isn’t always better.” Just as with any medication, there are risks with vitamins.
Aside from possible nausea, diarrhea, and vomiting as side effects of vitamins that some people experience, it is possible to overdose on certain vitamins. Data from 2021 reported that over 50,000 people called U.S. poison control centers that year regarding “vitamin toxicity.” Vitamin D is an example of a vitamin that has turned up in headlines in recent years as a vitamin that led to overdose for at least one American.
Vitamin A and vitamin C are others that have been bantered about colloquially in forums like social media as possible supplements that some individuals may be using, or administering to children, liberally.
Simply put, you can overdose on vitamins if you take more than the recommended dosage, or if you take additional supplements despite your body already having enough of these vitamins. Overdosing on vitamins can cause organ damage, particularly liver damage, and can even be fatal, though death from vitamins is rare.
There is one caveat: It’s unlikely to overdose on vitamin B-12, a water-soluble vitamin, as well as some other B vitamins. Your body absorbs the amount of B-12 it needs and then excretes the rest through your urine. This is why you may find your urine is a brighter yellow than usual after taking B-12. “The color change is harmless, but it’s a sign you may be getting more than you actually need,” Dr. Varacallo says.
Overall, it’s more likely to overdose on fat-soluble vitamins than water-soluble ones. However, as Healthline has noted, it’s not impossible to overdose on water-soluble vitamins if you’ve taken a large dose.
Vitamin overdose symptoms
While the exact symptoms you experience may vary based on the vitamins taken, common symptoms of a vitamin overdose include:
- Frequent urination or an increased amount of urine expelled
- Cloudy urine
- Eye irritation or sensitivity to light
- Irregular or rapid heartbeat
- Pain in bones, joints, or muscles
- Muscle weakness
- Mood changes, confusion, or irritability
- Fainting or fatigue
- Headache
- Dry or itchy skin
- Rash
- Loss of appetite
- Nausea and vomiting
- Stomach pain
- Constipation or diarrhea
If you’re experiencing a long-term overdose—taking too many vitamins over a long period of time—you may experience symptoms such as weight loss, hair loss, or dry lips, according to Mount Sinai.
What to do if you suspect you’ve overdosed on vitamins
If you believe you may have overdosed on vitamins, seek medical help immediately. Contact poison control or the national toll-free Poison Help hotline at 1-800-222-1222. You do not have to be experiencing a medical emergency to call. The hotline can be reached 24 hours a day, seven days a week. You may also call your doctor or 911.
“If your symptoms are severe, such as confusion, difficulty breathing, or irregular heartbeat, seek emergency medical attention immediately,” Dr. Varacallo says. There, medical staff will monitor your vital signs and admit you to the hospital if necessary. Expect to undergo a few tests like blood and urine tests. Treatment may include taking activated charcoal, receiving fluids via an IV, taking a laxative, and receiving medicine. If you’re experiencing trouble breathing, hospital staff may administer oxygen via tube or ventilator.
The bottom line is never to take or give another individual, including a child or senior, a vitamin or supplement without a doctor’s recommendation. And then, always follow the indicated dosage. Think of vitamins not just as supplements, but as medication. There is, indeed, such thing as “too much of a good thing.”
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Sources
- Mayo Clinic: "Vitamin C"
- Mayo Clinic: "Vitamin B-12"
