It didn’t take long for concerns about RFKs unscientific ideological approach to healthcare to manifest. We are in the middle of a measles outbreak – the exact kind of situation for which we need a strong federal response. The person in charge of that response, RFK Jr., is a notorious anti-vaccine crank who is not a scientist or healthcare expert, even though he acts as if he is.
His response to the outbreak has not been as bad as feared, in that he does support the use of vaccines and does say that vaccines work to prevent disease and provide community immunity. But he pairs that with the anti-vaccine dog whistle of saying that vaccines are a personal choice. He then immediately pivots to touting vitamin A and cod liver oil as treatments for measles, saying that, “Studies have found that vitamin A can dramatically reduce measles mortality.” He links to this 2010 study.
This is a great example of how easy it is to mislead by presenting scientific evidence, through cherry picking and misrepresentation. Kennedy also cites that the CDC now recommends vitamin A for the treatment of measles. But this is what the CDC has to say:
“Supportive care, including vitamin A administration under the direction of a physician, may be appropriate.”
That is a pretty luke warm recommendation. Doctors also understand what “supportive care” means – it is not a preventative or a therapeutic. It “may” help the patient weather the stress of the illness. Let’s take a look at the data to see what it actually shows.
Here is the most recent systematic review I could find, from 2017, which concludes:
“At longest follow-up, there was a 12% observed reduction in the risk of all-cause mortality for vitamin A compared with control using a fixed-effect model (risk ratio (RR) 0.88, 95% confidence interval (CI) 0.83 to 0.93; high-quality evidence).”
That is a 12% reduction in mortality, not the 65% cited by RFK’s study. But also we have to dig a bit deeper into the data. The review also found no preventive benefit from vitamin A – something that would be worth pointing out to the public, who may not distinguish between a supportive treatment and a preventive strategy.
There is concern that some people are using vitamin A routine supplementation, sometimes in high doses, to prevent measles, prompting responsible healthcare experts to specifically point out that this does not work and vitamin A is not a substitute for vaccination. Also, vitamin A is likely the most toxic vitamin in high doses, which is also important to warn the public about.
Still, you might be thinking, a 12% reduction in mortality is significant and the public should be made aware of this. But the data showing a reduction in mortality from measles using vitamin A is limited to countries where vitamin A deficiency is rampant. Measles can cause a further depletion of vitamin A, and both measles and vitamin A deficiency weaken the immune system. So yes, in parts of the world where vitamin A deficiency is common, targeting those with measles for vitamin A supplementation is beneficial. The data shows is works for children less than two years old, and with two high dose administrations of vitamin A.
Does this data apply to a measles outbreak in the US? No, not at all. In fact, the one study specifically looking at vitamin A for the treatment of measles in a high income country found no benefit.
It is therefore more accurate to say that young children at high risk for vitamin A deficiency should be specifically targeted for supplementation if they contract measles or during a measles outbreak. But vitamin A is not a specific treatment for measles, it has no benefit in children who are not at high risk of vitamin A deficiency, and it has no role in prevention.
Just saying that “studies have found” vitamin A to “dramatically reduce measles mortality” in the context of an outbreak in Texas is more than misleading. It is dangerous. It will likely have an impact on public behavior which is counter productive (classic RFK jr).
What the public should be told, if they are told anything, is what all the data, put into a proper medical context, actually is telling us – while vitamin A may be helpful for supportive care of some patients, vitamin A is unlikely to be of any benefit in a measles outbreak in the US. It is not a treatment for measles itself, and it is not effective for prevention. Only vaccines (along with isolation and avoidance of contact) can effectively prevent the contraction of measles, which is a highly contagious illness. Do not take high doses of vitamin A, and do not use vitamin A to self-treat measles or as a substitute for the vaccine.
