Vitamin A overdoses rose by 38.7% in 2025: How do you get the right amount?

• Data provided by America’s Poison Centers indicates that there was a 38.7% increase in vitamin A overdoses between January and March 2025.
• This period coincides with the measles outbreak in 2025 affecting people in 45 jurisdictions of the United States.
• A new public health research letter published in JAMA Network Open hypothesizes that the exposure to vitamin A is most likely due to the spread of misinformation regarding the role of this dietary supplement in the prevention and treatment of measles.
• The letter warns of the dangers of misinformation spread by sources widely trusted by the U.S. public.
• Medical News Today spoke to a family medicine physician and a dietitian to disentangle fact from fiction regarding the best sources of vitamin A, how much of it is too much, and whether it can really help prevent or treat measles.

According to America’s Poison Centers, between January 1 and March 31, 2025, there were 86 cases of “vitamin A exposures,” referring to overdoses of vitamin A, among children.

This, they note, represents “a 38.7% increase compared to the same period in 2024.” The figures are striking, particularly in relation to a dietary supplement that generally ought to be harmless.

So what happened? A team of researchers from Boston Children’s Hospital in Massachusetts, Harvard Medical School, the School of Public Health at the University of California, Berkeley, and the Department of Public Health at Brigham Young University in Provo, UT, have a hypothesis.

In a public health research letter recently published in JAMA Network Open, they draw a link between the abrupt year-on-year hike in vitamin A exposures and the measles — a viral disease — outbreak in 2025, which corresponds to the period during which America’s Poison Centers recorded the increase in cases.

In 2025, there was a total of 2,288 officially recorded measles cases, of which 93% occurred among children and adults who were either unvaccinated with the MMR vaccine, or whose vaccination status remained unrecorded. The outbreak affected people in 45 jurisdictions of the United States.

The research letter authors link the increase in vitamin A exposures to the rise at that time in misinformation regarding the role that vitamin A might play in the prevention and treatment of measles.