Use of Vitamin A in the Treatment of Measles

Measles is considered one of the most contagious infectious diseases, yet it wasn’t until 1963 that the first measles vaccine was licensed for distribution in the United States. Prior to vaccination an estimated average of 549,000 measle cases were seen in the U.S. each year. The following decades saw a drastic drop in domestic cases, leading to an announcement in 2000 that measles had been eliminated. However, measles continues to be an infectious disease of interest.

Smaller outbreaks of measles continue to appear in relatively small numbers throughout the U.S., although larger communities are occasionally affected. Additionally, worldwide incidence of measles remains of concern. In 2023, measles was responsible for about 107,500 deaths worldwide, mostly in children.

Vaccination is the strongest defense against measles, and certain groups are more susceptible to negative health outcomes if they become infected. Those at particular risk include children younger than 5, pregnant individuals and those with malnutrition or weakened immune systems. Additionally, those who are vitamin A deficient are at increased risk of adverse effects, making this vitamin of particular interest in the treatment of measles.

The Role of Vitamin A

Most research on vitamin A in the treatment of measles is focused on children. Meta-analyses indicate that vitamin A supplementation, under the supervision of a physician, may reduce mortality in children younger than 2 years of age. Additionally, it may reduce the severity of measles cases in those who are vitamin A deficient when appropriately used as a complementary therapy to other clinical interventions.

The American Academy of Pediatrics (AAP) and the Centers for Disease Control and Prevention offer specific recommendations on vitamin A supplementation in the treatment of measles. Under the supervision of a health care provider, the following single doses are recommended over two consecutive days:

• 50,000 International Units (15,000 micrograms) for infants younger than 6 months
• 100,000 International Units (30,000 micrograms) for infants 6 through 11 months of age
• 200,000 International Units (60,000 micrograms) for children 12 months or older

Additionally, the AAP recommends a third age-specific dose of vitamin A for children who show clinical signs of vitamin A deficiency, two to six weeks after the initial doses.

These are large doses of vitamin A that exceed the Tolerable Upper Intake Limit (UL) if given as preformed vitamin A. If given inappropriately, there is a risk of toxicity from hypervitaminosis A.

Vitamin A Toxicity and Other Considerations

Vitamin A is a fat-soluble vitamin, meaning the body does not excrete excess amounts as quickly as vitamins that are water-soluble. Vitamin A is available in two main forms; preformed vitamin A is the only form of concern when discussing toxicity, also known as hypervitaminosis A. However, preformed vitamin A accounts for 60% to 85% of the vitamin A intake in the United States. Preformed vitamin A is found in animal sources, such as eggs, fish, organ meats and dairy. Alternatively, foods with provitamin A can be consumed without fear of hypervitaminosis A. These sources include vegetables and fruits, such as sweet potatoes, carrots, peppers and mangos.

Complications of hypervitaminosis A can be severe. In children, excess intake is associated with pneumonia, bone pain and diarrhea and increased risk of liver failure. Additional side effects may include blurred vision, dizziness, coma and death.

Individuals who are pregnant should take caution not to exceed the UL of 3,000 micrograms per day, as it increases the risk of fetal malformations, including craniofacial abnormalities and abnormalities of the central nervous system.

References:

• U.S. Centers for Disease Control and Prevention. Clinical Overview of Measles. July 15, 2024. Accessed March 11, 2025.
• World Health Organization. Measles Fact Sheet. Accessed March 11, 2025.
• Kimberlin DW, Banerjee R, Barnett ED, Lynfield R, Sawyer MH. 2024. Measles. Red Book: 2024–2027 Report of the Committee on Infectious Diseases, Committee on Infectious Diseases. American Academy of Pediatrics.
• NatMed Pro. Vitamin A Professional Monograph. Accessed March 11, 2025 .
• U.S. Department of Health and Human Services. Office of dietary supplements - vitamin A and carotenoids. NIH Office of Dietary Supplements. Accessed March 11, 2025.
• Wallace, T.C. 2023. Health Professional's Guide to Dietary Supplements. Academy of Nutrition and Dietetics.