Poisonings due to unproven measles cures rose by nearly 40 percent in three months, a new report shows.
Vitamin A and cod liver oil have emerged as popular ‘cures’ for the measles virus, which causes fever, cough, and rash and in severe cases, pneumonia and encephalitis, or brain swelling.
The US saw an outbreak of measles in the early winter to spring of 2025, driven largely by unvaccinated people, who made up over 93 percent of cases.
Internet searches for vitamin A and cod liver oil spiked between January 1, 2025, and March 31, 2025, compared to the same period in 2024, and reached their highest level on March 22, by which point at least 378 cases were confirmed.
Around the same time that online searches for vitamin A spiked, America’s Poison Centers reported a 38.7 percent increase in vitamin A poisonings, meaning more people accidentally overdosed on these supplements.
Researchers behind the latest report on poisonings said: ‘This trend may have been influenced by public figures who have increasingly promoted vitamin A to treat measles.’
Top federal health figures, among them Health and Human Services Secretary Robert F Kennedy Jr, have sparked debate by promoting vitamin A and cod liver oil as unproven measles remedies and protection against the disease.
But doctors warn that vitamin A doesn’t stop measles infection, and taking these supplements incorrectly has caused serious poisoning.
Just because vitamin A and cod liver oil come from natural sources does not mean they are harmless in large amounts, experts warn (stock)
Since January 2025, more than 4,300 cases of measles have been confirmed in the US, according to federal data.
Many people assume that because vitamin A and cod liver oil are ‘natural,’ they must be safe. But that is not true at high doses.
Unlike water-soluble vitamins that exit the body through urine when someone takes too much, vitamin A is fat-soluble.
This means it gets stored in the liver and fat tissue. Over time, high doses build up to dangerous levels instead of being flushed out.
Cod liver oil, rich in vitamin A, for example, is often seen as a harmless old-fashioned remedy. In reality, just six teaspoons a day over several months can put an adult at risk of chronic toxicity.
For a small child, a fraction of that amount could cause serious harm.
Too much vitamin A can damage the liver, cause severe headaches and blurred vision from brain swelling, thin the bones, and dry out the skin.
In children, even smaller amounts can lead to nausea, coma or death. The most serious effects, including liver damage and brain swelling, may not be reversible.
Warning signs of a measles infection include a high fever, followed by a red rash that starts on the head before spreading over the body (stock image)
‘While it is not unusual for people to reach for acetaminophen (Tylenol) or ibuprofen to relieve fever or pain, the sudden interest in vitamin A in response to the measles outbreak was neither expected nor evidence-based, as it does not prevent measles,’ the researchers said in JAMA Network Open.
‘So what led to this uptick in search?’
The timing of the search spikes lined up with two major moments: starting February 19, 2025, when public figures first began touting vitamin A for measles, and later, when Dr Suzanne Humphries appeared on Joe Rogan’s podcast to praise vitamin A and cod liver oil as remedies.
After the media coverage began, searches for vitamin A were, on average, 7.5 percentage points higher than what researchers would have expected without that coverage. For cod liver oil, searches were 1.3 percentage points higher.
Last spring, doctors at Covenant Children’s Hospital in Lubbock, Texas, treated several pediatric measles patients who showed signs of vitamin A toxicity, including abnormal liver function.
The hospitalized children were all unvaccinated against measles.
Acute vitamin A toxicity occurs in adults above 300,000 IU in a single dose, and in children above 100,000 IU or roughly 20,000 IU per kilogram.
Chronic toxicity can develop in adults taking over 25,000 IU daily for months, and in children taking over 10,000 IU daily for weeks or 1,500 to 2,500 IU per kilogram per day.
The graph shows that Google searches for ‘vitamin A measles’ (dark blue) and ‘cod liver measles’ (orange) spiked in early 2025, coinciding with media statements promoting these supplements as treatments
The graph shows that after media figures began promoting cod liver oil for measles on February 19, 2025, online searches for the term rose 1.3 percentage points above expected levels (dashed line)
The most vulnerable are at greatest risk. Infants, young children, pregnant women, and people with liver disease can suffer toxic effects at much lower doses than healthy adults.
Symptoms of vitamin A poisoning include nausea, dizziness, blurry vision, liver damage, and in severe cases, coma or even death.
For cod liver oil at 4,000–5,000 IU of vitamin A per teaspoon, chronic toxicity may occur in adults consuming about six teaspoons — 30,000 IU — daily long-term, with far lower amounts endangering children, infants, pregnant women, and those with liver disease.
Researchers said: ‘Our findings underscore media’s influence on health-seeking behavior during public health emergencies like the measles outbreak, which is particularly concerning when guidance from trusted sources is unclear and may encourage detrimental behaviors at the expense of essential public health measures.
‘Measles resurgence in the US highlights the need for heightened public awareness, stronger vaccination campaigns, and science-backed messaging from health officials to prevent future outbreaks.’
The measles, mumps, rubella (MMR) vaccine is the only way to prevent measles in the first place, and there is no proven cure for measles.
The MMR vaccine is highly effective. Two doses protect against measles with about 97 percent effectiveness, meaning 97 out of every 100 people who get both doses will never catch measles, even if exposed. One dose offers around 93 percent protection.
It works by introducing a harmless, weakened version of the measles virus into the body. This triggers the immune system to produce defense proteins that remember how to fight the real virus.
If a vaccinated person is later exposed to measles, their immune system recognizes and destroys the virus immediately, preventing infection before symptoms ever start. This is why vaccinated people rarely get measles, even during outbreaks.