Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.
About Vitamin A
Vitamins are substances that your body needs to grow and develop normally. Vitamin A plays a role in your:
- Vision
- Bone growth
- Reproduction
- Cell functions
- Immune system
Vitamin A is an antioxidant. It can come from plant or animal sources. Plant sources include colorful fruits and vegetables. Animal sources include liver and whole milk. Vitamin A is also added to foods like cereals.
Vegetarians, young children, and alcoholics may need extra Vitamin A. You might also need more if you have certain conditions, such as liver diseases, cystic fibrosis, and Crohn's disease. Check with your health care provider to see if you need to take vitamin A supplements.
It sits within Food and Nutrition.
The lead U.S. institute for this subject is the NIH Office of Dietary Supplements.
When to speak to someone. Reading about a topic cannot tell you whether it applies to you. Speak to a doctor or pharmacist if symptoms are severe, sudden, getting worse, or simply not going away — and seek emergency care immediately for chest pain, breathing difficulty, sudden weakness or confusion, or a serious allergic reaction.
Research on Vitamin A
1,674 studies areregistered for this condition on ClinicalTrials.gov, the U.S. National Library of Medicine's public registry. A selection is below — the links go straight to the registry entry, not to a summary of ours.
What a registered study does and does not mean. Registration means a study exists and has been declared publicly. It says nothing about whether the treatment being tested works, is safe, or is available to you. Many studies find no benefit — that is what research is for. Never seek out an experimental treatment on the strength of a registry entry alone.
Research currently under way
- Vitamin A Supplementation and Breast Milk Vitamin A Levels in Mothers of Preterm InfantsUniversity of Mississippi Medical Center
- Vitamin D Status and Asthma Control, Pulmonary Function, and Oxidative Stress in Adults With Bronchial AsthmaSinai University
- Vitamin D Status and Lipid Profile in Obese Adults With Type 2 DiabetesSinai University
- Effect of the Consumption of Cookies Enriched With Plant Proteins and of a Vitamin D Supplement on the Progression of Sarcopenia in the ElderlyUniversity of Udine
- Vitamin B12 Absorption StudyRDC Clinical Pty Ltd
- Benfotiamine Versus Vitamin B1-6-12 for Diabetic Peripheral NeuropathyThammasat University
Research already completed
- The Investigation of Vitamin D and Menstrual Cycles Trial, the inVitD Trial: A Phase II Clinical TrialNational Institute of Environmental Health Sciences (NIEHS)
- A Phase 2 Trial of High-dose Ascorbate for Pancreatic Cancer (PACMAN 2.1)University of Iowa
- GLUT-F Improves MASLD Liver FunctionUniversity of Bari
- Vitamin D Therapy to Prevent Recurrent Preeclampsia in High-Risk PregnanciesCMH Multan Institute of Medical Sciences
- The Potential Effect of the Local Administration of Vitamins C and E on Orthodontic Treatment: A Randomized Clinical TrialUniversity of Baghdad
- A Study to Describe the Lived Experience of XLH for Adolescents at End of Skeletal GrowthKyowa Kirin Pharmaceutical Development Ltd
Study data from ClinicalTrials.gov, a service of the U.S. National Library of Medicine. Retrieved 2026-07-30. Registry entries are supplied by study sponsors and investigators; ClinicalTrials.gov does not verify their scientific validity. PocketsInfo is not affiliated with, and not endorsed by, the NLM or the NIH.
Where to read more
Rather than paraphrase, we point you to the primary sources. Every link below is to a government health agency, a national institute or a recognised medical body — grouped by what you are trying to find out.
Start Here
- Vitamin AHarvard School of Public Health
- Vitamin A and CarotenoidsNational Institutes of Health, Office of Dietary Supplements
Clinical Trials
- ClinicalTrials.gov: Vitamin ANational Institutes of Health
Medical subject headings
Clinicians and researchers index this subject under Vitamin A. These are the terms to use when searching medical literature.
This page is built from the MedlinePlus health topic record for Vitamin A, a service of the U.S. National Library of Medicine (NLM), National Institutes of Health. Information is from MedlinePlus.gov. PocketsInfo is not affiliated with, and is not endorsed by, the NLM or the NIH. Retrieved 30 July 2026.