Robert F. Kennedy Jr says vitamin A protects you from deadly measles. Here’s what the study he cites actually says

Robert F. Kennedy Jr, who oversees the health of more than 340 million Americans, says vitamin A can prevent the worst effects of measles rather than urging more people to get vaccinated.

In an opinion piece for Fox News, the US health secretary said he was “deeply concerned” about the current measles outbreak in Texas. However, he said the decision to vaccinate was a “personal one” and something for parents to discuss with their health-care provider.

Kennedy mentioned updated advice from the Centers for Disease Control (CDC) to treat measles with vitamin A. He also cited a study he said shows vitamin A can reduce the risk of dying from measles.

Here’s what the vitamin A study actually says and why public health officials are so concerned about Kennedy’s latest statement.

Why is a measles outbreak so worrying?

Measles is a highly contagious disease caused by a virus. It spreads easily including when an infected person breathes, coughs or sneezes.

Measles initially infects the respiratory tract and then the virus spreads throughout the body. Symptoms include a high fever, cough, red eyes, runny nose and a rash all over the body.

Measles can also be severe, can cause complications including blindness and swelling of the brain, and can be fatal. Measles can affect anyone but is most common in children.

The Texan health department has confirmed 150-plus cases of measles and one death of an unvaccinated child during the current outbreak. While this is by far the largest measles outbreak in the US in 2025, the CDC has reported smaller outbreaks in several other states so far this year.

Why vitamin A?

Vitamin A is essential for our overall health. It has many roles in the body, from supporting our growth and reproduction, to making sure we have healthy vision, skin and immune function.

Foods rich in vitamin A or related molecules include orange, yellow and red coloured fruits and vegetables, green leafy vegetables, as well as dairy, egg, fish and meat. You can take it as a supplement.

Vitamin A can also be used therapeutically. In other words, doctors may prescribe vitamin A to treat a deficiency. Vitamin A deficiency has long been associated with more severe cases of infectious disease, including measles. Vitamin A boosts immune cells and strengthens the respiratory tract lining, which is the body’s first defence against infections.

Because of this, the CDC has recently said vitamin A can also be prescribed as part of treatment for children with severe measles – such as those in hospital – under doctor supervision.

One key message from the CDC’s advice is that people are already sick enough with measles to be in hospital. They’re not taking vitamin A to prevent catching measles in the first place.

The other key message is vitamin A is taken under medical supervision, under specific circumstances, where patients can be closely monitored to prevent toxicity from high doses.

Vitamin A toxicity can cause birth defects and increase the risk of fractures in elderly people. Vitamin A and beta-carotene (which the body turns into vitamin A) from supplements may also increase your risk of cancer, especially if you smoke.

Taking too much vitamin A can lead to toxicity and cause birth defects.
ChameleonsEye/Shutterstock

How about the study Kennedy cites?

Kennedy cites and links to a 2010 study, a type known as a systematic review and meta-analysis. Researchers reviewed and analysed existing studies, which included ones that looked at the effectiveness of vitamin A in preventing measles deaths.

They found three studies that looked at vitamin A treatment by specific dose. There were different doses depending on the age of the children, measured in IU (international units). Having two doses of vitamin A (200,000IU for children over one year of age or 100,000IU for infants below one year) reduced mortality by 62% compared to children who did not have vitamin A.

The 2010 study did not show vitamin A reduced your risk of getting measles from another infected person. To my knowledge no study has shown this.

To be fair, Kennedy did not say that vitamin A stops you from catching measles from another infected person. Instead, he used the following vague statement:

Studies have found that vitamin A can dramatically reduce measles mortality.

It’s easy to see how a reader could misinterpret this as “take vitamin A if you want to avoid dying from measles”.

We know what works – vaccines

The World Health Organization recommends all children receive two doses of measles vaccine.

The CDC states two doses of the measles vaccine (measles-mumps-rubella or MMR vaccine) is 97% effective against getting measles. This means out of every 100 people who are vaccinated only three will get it, and this will be a milder form.

But these facts were missing from Kennedy’s statement. Should we be surprised? Kennedy is well known for his vaccine sceptism and for undermining vaccination efforts, including for the measles vaccine.

As Sue Kressly, president of the American Academy of Pediatrics, told the Washington Post:

relying on vitamin A instead of the vaccine is not only dangerous and ineffective […] it puts children at serious risk.