Vitamin A supplementation is beneficial in reducing morbidity and mortality associated with measles, particularly in children with vitamin A deficiency or in areas where such deficiencies are common. Studies show that children receiving vitamin A recover more rapidly from complications such as pneumonia, diarrhea, and croup, spend fewer days in the hospital, and have a lower risk of death, by half in some cases, compared to those who do not receive supplementation. Recommended dosing for vitamin A is a 2-day dose of 50,000, 100,000, or 200,000 units/d for patients <6, 6–11, or ≥12 months, respectively. Because of the pharmacodynamics of vitamin A, it is most effective when given orally/enterally. While the benefit is evident in underdeveloped countries, a recent study in 2020 in Italy showed no difference between the study groups in the duration of fever (7.03 ± 2.67 vs. 6.82 ± 3.27, P = 0.72), length of hospitalization (median, 5.0 vs. 5.0 days, P = 0.50), maximum body temperature (median, 39°C in both groups, P = 0.23), rate of organ (69.4% vs. 63.9%, P = 0.72) and hematologic complications (41.7% vs. 59.7%, P = 0.12), or need for antibiotic treatment (66.7% vs. 61.1%, P = 0.72). Despite the findings in high-income settings, vitamin A is widely recommended by health authorities like the World Health Organization and the American Academy of Pediatrics for managing measles in children. This is based on evidence from regions with prevalent vitamin A deficiency, where supplementation has been shown to reduce the risk of severe complications and mortality. This is also likely based on a biochemical hypothesis of reduced serum vitamin A induced by the measles virus. Measles, a viral infection, can lead to lower vitamin A levels in the blood, even in well-nourished children. This happens because the disease causes inflammation, which reduces retinol-binding protein (RBP), the protein responsible for moving vitamin A from the liver into the bloodstream. As a result, while the liver may still have adequate vitamin A, the amount available in the blood drops, potentially worsening the infection's impact. As you'll see, Vitamin A plays a crucial role in several bodily functions.
Vitamin A Sources and Function
Nutrient sources of vitamin A include dark leafy greens, orange-colored vegetables (like carrots), milk products, liver, and fish. Beta-carotene is the most well-known form of 2 clinically significant forms of vitamin A: preformed vitamin A and provitamin A carotenoids. After hydrolyzation by pancreatic and intestinal enzymes, vitamin A is absorbed in the duodenum and made transportable in the blood with dietary fats and bile acids. The majority is then stored in the liver in hepatic stellate cells. Adipose tissue and the pancreas also contain vitamin A.
The recommended dietary allowance (RDA) of vitamin A in healthy adults is 700 micrograms/day for women and 900 micrograms/day for men. For children, pregnant women, and lactating women, the RDA is 300 to 900, 7850-770, and 1200-1300 micrograms/day, respectively. The minimum requirement to prevent symptomatic VAD in children 1 to 5 years of age is about 200 micrograms/day, and we can measure serum retinol levels as a relative measurement of vitamin A status. Deficiency is defined as a retinol concentration of fewer than 20 micrograms/dL. Ocular symptoms that can lead to blindness have been shown to develop at less than 10 micrograms/dL. Top food sources in decreasing order of vitamin A amount include beef liver (cooked), sweet potato, spinach, kale, carrots, pumpkin, red bell pepper (raw), mango (raw), cantaloupe (raw), egg, and cheddar cheese.
Vitamin A absorption occurs in the small intestinal tract and supports retina pigmentation, maintaining mucous membranes and immune function. Due to the absorption site, patients with bariatric surgery, as well as premature neonates, can present with low vitamin A. In an acute measles infection, patients can present Xerophthalmia or dry eyes, decreased vision at night, spots on their cornea (bitot spots), and conjunctival xerosis. These can resolve over 2 months with vitamin A supplementation. Corneal ulcerations and xerosis, unfortunately, have a more permanent effect on decreased vision as well as a poorer prognosis.
Vitamin A Toxicity
In normal amounts, vitamin A is healthy; however, high levels of ingested vitamin A can lead to hypervitaminosis A. This typically arises when an individual consumes over 100,000 RAE within a short period from supplements or high-dose medications. A common question in medical school is a patient who is a bear hunter presents with peeling skin, hair loss, vision changes, bone and joint pain, fatigue, and liver damage. These are symptoms of too much vitamin A due to the hunter consuming bear liver. Like everything in medicine, the dosage matters.
Unfortunately, with the current outbreak of measles in west Texas, Covenant Children's Hospital in Lubbock confirms it is treating children with severe cases of measles who are also suffering from vitamin A toxicity leading to abnormal liver function. Treatment involves discontinuing vitamin A intake, providing supportive care, and managing symptoms. Hypotension can be managed with fluid administration, and hypercalcemia can be treated with calcitonin and corticosteroids. Emolients or moisturizers can alleviate discomfort from dry or peeling skin. Artificial tears and lubricating eye drops can be used for dry eyes. Highly elevated triglyceride levels to 800 mcg/dL or higher lipid-lowering medications can be considered to prevent pancreatitis. Acetazolamide may be used in cases of pseudotumor cerebri (increased intracranial pressure). Unfortunately, the embryo is especially prone to the teratogenic effects on the neural crest of excessive amounts of vitamin A during the first trimester, which is why retinoid medications are not prescribed to pregnant patients.
Note: No evidence indicates that taking vitamin A will prevent measles.
The Resurgence of Measles
A Morbillivirus, double-stranded RNA virus, causes measles. Transmitted by infectious droplets and aerosolization (i.e. coughing and sneezing), it is highly contagious. An enclosed space is considered a potential source of infection for 2 hours after someone with measles has left. An infected person can pass it to 9 out of 10 people around them. In 2000, measles was declared eliminated from the United States; however, after COVID-19, the nation tended towards vaccine hesitancy, increasing the number of cases yearly. Most cases have occurred in patients with unvaccinated or unknown vaccination status (94%, up from 89% in 2024).
Current U.S. Cases
According to the CDC.
Total Cases: 483
Age
Under 5 years: 157 (33%)
5-19 years: 204 (42%)
20+ years: 111 (23%)
Age Unknown: 11 (2%)
Vaccination Status
Unvaccinated or Unknown: 97%
One MMR Dose: 1%
Two MMR Doses: 2%
As of March 27, 2025, a total of 483 confirmed* measles cases were reported by 20 jurisdictions: Alaska, California, Florida, Georgia, Kansas, Kentucky, Maryland, Michigan, Minnesota, New Jersey, New Mexico, New York City, New York State, Ohio, Pennsylvania, Rhode Island, Tennessee, Texas, Vermont, and Washington.
Typical Symptoms
From the American Family Physician magazine.
"The incubation period for measles is typically 10 to 12 days but can be as long as 21 days. Illness starts with a high fever and the 3 Cs: cough, coryza, and conjunctivitis. After about 4 days, an erythematous, maculopapular rash appears on the face and spreads downward to cover the body. This rash lasts about 6 days. Koplik spots (tiny white spots inside the mouth) may also appear 2 or 3 days after the first symptoms. A person with measles is infectious 4 days before through 4 days after the appearance of the rash."
Macular Papular Rash caused by the Measles virus
There are no antiviral medications to treat measles right now. Care is provided to improve the symptoms and reduce the possibility of bacterial infections. The best prevention method is the measles vaccine, typically given at 12 months and again at 4 years old in the measles, mumps, and rubella formulation. Recent health and human services appointee Robert F. Kennedy Jr. recommends the vaccine to reduce the chances of getting measles.
Understanding Good Data
I wanted to cover this topic quickly because I knew this article might attract many new readers unfamiliar with scientific data. There are three main points to consider when examining a scientific study.
- Is the population relative to me?
- Were there enough people involved?
- Was the trial blinded and randomized?
If you are a female in your 40s and Hispanic, then you want the study's population to be around the same age, gender, and ethnicity. Likewise, you want the survey to include a large group of people around the same demographic as you to ensure they capture the same genetic variations and lifestyle habits. Blinding the study means the researchers and participants do not know if they gave or received vitamin A, which helps to decrease their bias. Timing plays a crucial role when first evaluating a pediatric patient. Because children can quickly deteriorate, medications and life-saving interventions may be done before labs are drawn. This means that a child may receive vitamin A before a blood sample is taken, making it challenging to study cases where vitamin A has not been given. I'll go more in-depth on good studies later, but we can now discuss a rigorous trial conducted in Africa and featured in the New England Journal of Medicine.
The Trial
From March to July 1987, a randomized, double-blind trial involving 189 children hospitalized at a regional center in South Africa was conducted on children admitted because of measles complicated by pneumonia, diarrhea, or croup. The children (median age, 10 months) were assigned to receive either vitamin A (total dose, 400,000 IU of retinyl palmitate, given orally; n = 92) or placebo (n = 97), beginning within five days of the onset of the rash. The criteria for exclusion were vitamin A therapy before admission, xerophthalmia on admission or thereafter, rash for more than four days, or lack of parental consent.
What They Found
The children who received vitamin A had markedly diminished mortality and morbidity, with no clinically adverse effects. Compared with the placebo group, the children who received vitamin A recovered more rapidly from pneumonia, 6.3 vs 12.4 days, and spent fewer days in the hospital, 10.6 vs 14.8 days. Of the children who died, 10 were among those given a placebo. For the group treated with vitamin A, the risk of death or a complication during the hospital stay was half that of those who did not receive vitamin A.
Supporting Conditions
The hospital's local computer database listing of inpatients found only three clinical vitamin A deficiency instances among 161,381 children admitted over 13 years with no cases since 1985. This is important because it helps to exclude the possibility of low vitamin A due to malnutrition. Hyporetinemia, vitamin A deficiency, has also been found in fever, pneumonia, rheumatoid arthritis, hepatitis, acute tonsillitis, rheumatic fever, and protein energy malnutrition.
Further Investigation
There are some drawbacks to this study. It was not multicenter, which would help to include a more diverse population. Vitamin A levels (retinol) were not tested again after recovery, which is essential to ensure continued infusions of vitamin A are not needed. Higher to lower levels of administered vitamin A need to be compared to determine the minimum effective dose.
The Bottom Line
The high-quality scientific investigation in Africa seems to support the use of Vitamin A to help reduce the mortality and complications of measles. From the previously mentioned studies of lower quality, vitamin A appears to help decrease the symptoms of the Measles virus at appropriate dosages. I would not As always, consult your doctor and tailor your choices to your current life circumstances.
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References
- Carazo A, Macáková K, Matoušová K, Krčmová LK, Protti M, Mladěnka P. Vitamin A Update: Forms, Sources, Kinetics, Detection, Function, Deficiency, Therapeutic Use and Toxicity. Nutrients. 2021 May 18;13(5):1703. doi: 10.3390/nu13051703. PMID: 34069881; PMCID: PMC8157347.
- Hussey, G., & Klein, M. (1990). A randomized, controlled trial of vitamin A in children with severe measles.. The New England journal of medicine, 323 3, 160-4 . https://doi.org/10.1097/00006454-199012000-00022
- Hodge C, Taylor C. Vitamin A Deficiency. [Updated 2023 Jan 2]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK567744/
- Am Fam Physician. 2024;110(2):120-121, Practice Alert
- HPPR News : https://www.hppr.org/hppr-news/2025-03-28/west-texas-children-treated-for-vitamin-a-toxicity-as-medical-disinformation-spreads-alongside-measles, by David Martin Davies, Mar 28, 2025.
- Olson JM, Ameer MA, Goyal A. Vitamin A Toxicity. [Updated 2023 Sep 2]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK532916/
- CDC Vaccines and Immunizations, https://www.cdc.gov/vaccines/imz-schedules/child-easyread.html
