The Art and Science of Medicine: Vitamin A for Measles

Vitamin A is being touted by social media influencers, cable news personalities, politicians, and companies that sell supplements as a treatment for measles. Some have even suggested it be used as an alternative to vaccination for prevention.

This article will dive into the science of vitamin A and measles and discuss how this science is applied through “the art of medicine”. The primary sources for much of the information gathered for this article can be found here, here, here, and here.

Vitamin A deficiency contributes to delayed recovery and to risk of complications associated with measles infection. In at least one study blood levels of vitamin A fell in patients who had measles. For many years vitamin A has been used in the treatment of measles in specific doses and situations. It must be emphasized that large doses of vitamin A are toxic and have led to recent hospitalizations of children (in at least Texas).

It is well known that vitamin A deficiency contributes to delayed recovery and to risk of complications associated with measles infection. However studies of Vitamin A supplementation that have looked at the effects reducing measles severity and risk of complications have had mixed results. 

A meta-analysis of more than 1 million children across 19 countries found that vitamin A supplementation reduces measles-related mortality by 12%.

An analysis of eight randomized controlled trials found no overall mortality reduction from vitamin A. However, in three studies focused on African children under two years old, vitamin A supplementation reduced mortality by 79%.

There are limited studies of the effect of vitamin A treatment for measles in countries like the US where vitamin A deficiency is rare. 

One study including 108 inpatient children in Italy did not observe a benefit to vitamin A administration.

A study in Japan found that vitamin A supplementation did not reduce pneumonia risk in measles patients, though it did slightly shorten cough and fever duration.

What is vitamin A and why is it important?

There are two main forms of vitamin A  found in nature: provitamin A carotenoids (beta-carotene and others) and preformed vitamin A (retinol ). The term “provitamin” refers a substance that our bodies can convert to a vitamin. When a substance already in the form our bodies can use we call that a “preformed vitamin” .

Provitamin A carotenoids are found in plants. Preformed vitamin A (retinol, retinal, retinoic acid, and retinyl esters) is the most active form of vitamin A; it is mostly found in animal sources of food and is also the form supplied by most supplements. 

Vitamin A has a number of biologic actions including preventing vision, bone, and skin problems. Vitamin A deficiency can also lead to problems with immune function. 

Vitamin A deficiency is rare in the United States and other resource rich countries. Certain conditions can lead to problems with absorbing vitamin A.  People who have certain gastrointestinal surgeries may also need to take vitamin supplements including vitamin A.

We store up vitamin A and can accumulate toxic amounts. Vitamin A toxicity can result in long term consequences such as liver fibrosis and cirrhosis. Three syndromes of vitamin A toxicity have been recognized: acute, chronic, and teratogenic.

Adequate amounts of vitamin A are essential for the health of a developing fetus. However, retinoic acid, a metabolite of vitamin A, has been known to be very teratogenic in the first trimester of pregnancy, leading to spontaneous abortions and fetal malformations. Those who are or could become pregnant should avoid using retinoic acid which is used for certain skin conditions as well as excessive supplementation of vitamin A.

Large supplemental doses of retinol are very toxic to the liver. Acute toxicity occurs in adults when a single dose of >660,000 international units (>200,000 micrograms) of vitamin A is ingested. Symptoms include nausea, vomiting, vertigo, and blurry vision. In very high doses, drowsiness, malaise, and recurrent vomiting can follow the initial symptoms. In infants under six months of age, as little as 20,000 international units (6000 micrograms) daily, given briefly (eg, for one month or less), may produce toxic effects.

Chronic toxicity occurs with long-term excessive ingestion of the vitamin. For example; toxic effects of vitamin A have been observed in infants fed large amounts of chicken liver daily for one month or longer. Signs of chronic toxicity may include impaired balance and coordination, hair loss and measures of liver toxicity. Bone and muscle pain, visual impairments, and many other nonspecific signs and symptoms can occur.

Vitamin A taken in the amounts commonly found in multivitamins is not likely to cause any toxicity. The doses used for treating measles are higher and generally considered safe but should not be taken without medical supervision. Taking excessive doses that are being sold or  recommended by some influencers may not be safe and of little benefit. Taking excessive vitamin A will not “boost your immunity”. Vitamin A does not prevent measles and is not a substitute for vaccination.

So bottom line: should kids with measles in the United States be treated with vitamin A? It could be argued since there are limited studies suggesting benefit for kids without a vitamin A deficiency and that vitamin A deficiency is rare in the United States that vitamin A treatment should not  routinely be done. However, It must be recognized that we don’t have a great deal of information about using vitamin A in the US. Measuring vitamin A levels in every kid with measles is not practical and blood levels can be misleading – therefore a “test and treat” strategy to target those kids most likely to benefit may not work.

There are many ways of describing what the “art of medicine” is. Many of us in primary care practice the “art of medicine” when we work with patients over time developing relationships that go beyond just providing technical medical services. One could also think about “the science of medicine” in broader terms in how we use “the science of medicine” with humility in a compassionate manner.

When it comes to developing guidelines for treating measles we have the humility to admit the science is limited and consider how best to compassionately care for children. Therefore many experts and guidelines suggest treating hospitalized kids in the US with a specific 2 dose regimen of vitamin A.

The dose that is recommended has been shown to be effective in treating kids who are more likely to be vitamin A deficient and is reasonably safe.

Vitamin A deficiency is rare (less than 0.3%) in the US. Most of us do not need to supplement ourselves or our children (it is reasonable to take the low dose found in a multivitamin).

Vitamin A can be toxic and should not be taken at high doses. Vitamin A does not prevent measles .

See “Protection Against Measles” for more information on measles vaccination. 

In Infectious Diseases Update: Measles, Not Just a Rash I discuss the signs, symptoms and complications of measles.

As part of the “Health Matters in 2025” series I introduce some points for conversation about the societal issues complicating measles. For the first article on measles in what will be an ongoing series see Measles Outbreak and Religion.

Please note I am not an infectious disease or public health expert. I am a PA in a rural family practice clinic where I also provide hospital and emergency medicine services. This article is intended for general information and not as personal medical advice. Please see my full listing of  Disclosures, Disclaimers and Context.

For more information specific to infectious diseases please see Health and Medical Resources: Infectious Diseases and Public Health . I have been building this page with a list of  resources and will continue to add more information in the future.

Thank you for listening, please share this information with others and let me know what topics you want me to address in the future. I will be continuing my series of articles on fitness and nutrition soon as well as starting a new series on autism. For a full listing of Health Matters Articles click here.