Evidence Over Anecdotes: The Misuse of Vitamin A During Measles Outbreaks

In this issue of Pharmacy Practice in Focus: Health Systems, Azhar Hussain, DHA, PharmD, MBA; Syed Ahsan; and Sidhartha D. Ray, PhD, FACN, discuss the potential toxicities of fat-soluble vitamins A, D, E, and K in a literature review. Hypervitaminosis primarily from vitamins A and D is uncommon. However, the topic was considered relevant for pharmacists working in the health system setting, as the condition can be subtle in patients who present with it and is often believed to be the result of other diseases or exposures. The editorial team decided to publish this literature review to increase awareness and recognition of toxicities from fat-soluble vitamins, which are readily available and widely used.

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In the time since this paper was peer reviewed, revised, accepted, and now published, the topic of hypervitaminosis has been thrown into the national spotlight. In early March 2025, US Secretary of Health and Human Services Robert F. Kennedy Jr, through opinion pieces and nationally televised interviews, brought attention to the potential role of vitamin A in the treatment of measles infections during discussions of the multiple outbreaks occurring across the country, especially in West Texas. His comments were interpreted to support unfounded references to the vitamin’s role as prophylaxis for measles. He also made anecdotal references to the use of cod liver oil (a source of vitamin A), budesonide, and clarithromycin for patients with measles, an indication for which there is no supporting evidence.¹ Across social media outlets and influencer platforms, the promotion of vitamin A for the treatment and prevention of measles has blossomed, despite a lack of recommendations for vitamin A in this indication from the CDC or the World Health Organization (WHO).

Since the promulgation of vitamin A for measles treatment, patients with vitamin A toxicity have presented at children’s hospitals, and reports have appeared in the news.² On March 26, 2025, CNN published a report of patients with measles in West Texas with signs of vitamin A toxicity at Covenant Children’s Hospital in Lubbock.^2,3 Vitamin A in excess doses can lead to serious and potentially irreversible toxicities, including liver injury; additionally, no real-world evidence has shown its benefit in preventing measles infections.

The WHO does recommend the use of vitamin A under the supervision of a medical doctor for patients with acute measles infection. The recommendation is for 1 oral dosage at the time of diagnosis, and a second dose the next day. The recommended dose is age dependent and ranges from 50,000 IU (for patients aged < 6 months) to a maximum of 200,000 IU (for patients aged ≥ 12 months). If the child has clinical ophthalmic signs of vitamin A deficiency, a third dose should be given in 4 to 6 weeks.⁴ The CDC recommendations relative to vitamin A therapy mirror those of the WHO, except they specifically state that vitamin A is recommended for children with severe measles, such as those who are hospitalized.⁵

After a systematic review of 8 studies involving 2574 participants, a Cochrane review completed in 2005 concluded that there was no significant reduction in mortality in children receiving vitamin A. However, vitamin A supplementation was associated with a lower number of deaths from measles in hospitalized children under age 2.⁶ Regional differences are also likely, with certain areas having higher case fatality rates, and higher malnutrition and underlying vitamin deficiencies showing a greater benefit from vitamin A supplementation during acute measles infections. Conversely, studies conducted in higher-income countries were less likely to show benefit.¹ At best, the data support a conservative recommendation for dose-limited vitamin A supplementation (using CDC/WHO recommended doses) in the setting of acute measles infections, given the low risk and low cost associated with a 2-dose regimen. No evidence exists supporting larger doses, longer courses, or prophylactic use.

Reports of vitamin A toxicity due to apparent misuse of the vitamin for the treatment or prevention of measles are an essential reminder of the importance of context and evidence, and that irresponsible guidance or misinformation from unqualified individuals can be harmful. This is reminiscent of unsupported therapies being irresponsibly promoted by governmental officials during the early phases of the COVID-19 pandemic. At the time, at my health system, the University of Rochester Medical Center, we had to repeatedly dispose of large quantities of hydroxychloroquine shipped by the federal government because our review of the evidence indicated it would have been reckless to administer it to our patients.

Health system pharmacists can help educate the public in the ambulatory and acute care settings about the evidence-based role of vitamin A in acute measles infections, and do so in a respectful, compassionate, and evidence-based manner. Helping our patients differentiate sound evidence from social media hype and misinformation is increasingly challenging but remains crucial for trusted health care professionals.

REFERENCES

1. McDonald J. RFK Jr misleads on vitamin A, unsupported therapies for measles. FactCheck.org. March 7, 2025. Updated March 11, 2025. Accessed April 13, 2025. https://www.factcheck.org/2025/03/rfk-jr-misleads-on-vitamin-a-unsupported-therapies-for-measles/

2. Gerlach A. As the measles outbreak continues to spread, Texas hospitals report cases of vitamin A toxicity. Pharmacy Times. April 1, 2025. Accessed April 13, 2025. https://www.pharmacytimes.com/view/as-the-measles-outbreak-continues-to-spread-texas-hospitals-report-cases-of-vitamin-a-toxicity

3. Mukherjee N. Some measles patients in West Texas show signs of vitamin A toxicity, doctors say, raising concerns about misinformation. CNN Health, March 26, 2025. Accessed April 13, 2025. https://www.cnn.com/2025/03/26/health/texas-measles-vitamin-a-toxicity/index.html

4. Measles vaccines: WHO position paper – April 2017. Weekly Epidemiological Record. 2017;92(17):205-228. Accessed April 13, 2025. https://iris.who.int/bitstream/handle/10665/255149/WER9217.pdf?sequence=1

5. Clinical overview of measles. CDC. July 15, 2024. Accessed April 13, 2025. https://www.cdc.gov/measles/hcp/clinical-overview/index.html

6. Huiming Y, Chaomin W, Meng M. Vitamin A for treating measles in children. Cochrane Database Syst Rev. 2005;2005(4):CD001479. doi:10.1002/14651858.CD001479.pub3