Vitamin

Vitamin A Supplement Guide

Evidence-based information on Vitamin A benefits, dosage, safety, and food sources — sourced from NIH, FDA, and PubMed.

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Our assessment

The evidence shows that vitamin A is a critical nutrient for your immune system, but it requires careful dosing. Our assessment is that while a standard supplement can be beneficial, you must be cautious about the total amount of preformed vitamin A you consume daily, as the margin between a safe dose and a harmful one is narrow NIH ODS ↗.

How it works

Think of vitamin A as a master regulator for your body's defenses. It works by modulating both your innate and adaptive immune responses, helping your body recognize and fight off threats effectively NIH ODS ↗. This mechanism is essential for maintaining a healthy immune barrier in your skin and mucous membranes.

Safety profile

Data not available for specific side effect counts from the FDA data provided. However, the FDA has received a total of 7027 adverse event reports for this supplement FDA FAERS ↗. The NIH ODS warns that getting too much preformed vitamin A can cause severe headache, blurred vision, nausea, dizziness, muscle aches, and problems with coordination. In severe cases, it can lead to coma and death NIH ODS ↗. Be especially careful if you are pregnant, as high intakes can be harmful NIH ODS ↗. Also, if you take the weight-loss drug orlistat (Alli, Xenical), it can decrease the absorption of vitamin A, potentially requiring a different dosing strategy NIH ODS ↗.

Our recommendation

Start by reviewing all sources of preformed vitamin A in your diet and any multivitamins you take. Do not exceed the Tolerable Upper Intake Level without medical supervision. If you are taking orlistat, consult your doctor about monitoring your vitamin A levels NIH ODS ↗. Choose a supplement that provides vitamin A as beta-carotene when possible, as this form is safer because your body converts only what it needs NIH ODS ↗.

AI-assisted analysis based on NIH ODS, FDA, and PubMed data. Citations are linked to original sources.

7,027
FDA Reports
3
PubMed Studies
Vitamin
Category

Recommended Dosage

Recommended Dietary Allowance (RDA) / Adequate Intake (AI)
Life StageRecommended Amount
Birth to 6 months400 mcg RAE
Infants 7–12 months500 mcg RAE
Children 1–3 years300 mcg RAE
Children 4–8 years400 mcg RAE
Children 9–13 years600 mcg RAE
Teen males 14–18 years900 mcg RAE
Teen females 14–18 years700 mcg RAE
Adult males900 mcg RAE
Adult females700 mcg RAE
Pregnant teens750 mcg RAE
Pregnant women770 mcg RAE
Breastfeeding teens1,200 mcg RAE
Breastfeeding women1,300 mcg RAE

Source: National Academies of Sciences, Engineering, and Medicine. Always consult your healthcare provider for personalized dosage recommendations.

Drug Interactions

Yes, vitamin A supplements can interact or interfere with medicines you take. Here are several examples: Orlistat (Alli, Xenical), a weight-loss drug , can decrease the absorption of vitamin A. This can cause low blood levels of vitamin A in some people. Acitretin (Soriatane), used to treat psoriasis , and bexarotene (Targretin), used to treat the skin effects of T- cell lymphoma , are made from vitamin A. Taking these medicines together with a vitamin A supplement could cause dangerously high levels of vitamin A in the blood. Tell your doctor, pharmacist , and other health care providers about any dietary supplements and medicines you take. They can tell you if those dietary supplements might interact or interfere with your prescription or over-the-counter medicines or if the medicines might interfere with how your body absorbs, uses, or breaks down nutrients .

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Clinical Evidence

Vitamin A has been studied in 3+ clinical studies:

Dietary supplement consumption among active individuals in Saudi Arabia.

Alsayegh AA · 2026

A Framework for Developing Intake and Use Guidance for Dietary Supplement Bioactives.

Novotny JA · 2026

Patient Perceptions of Dietary Supplement Use and Kidney Stone Disease.

Kim DD · 2026

Health Goals This Supplement Supports

Frequently Asked Questions

How much Vitamin A should I take daily?

Refer to the Recommended Dosage table above. Individual needs vary by age, gender, and health status. Always follow the dosage on your supplement label and consult your healthcare provider.

What are the side effects of Vitamin A?

Yes, high intakes of some forms of vitamin A can be harmful. Getting too much preformed vitamin A (usually from supplements or certain medicines) can cause severe headache, blurred vision, nausea , dizziness, muscle aches, and problems with coordination. In severe cases, getting too much preformed vitamin A can even lead to coma and death. If you take too much preformed vitamin A while pregnant, i

Does Vitamin A interact with medications?

Yes, vitamin A supplements can interact or interfere with medicines you take. Here are several examples: Orlistat (Alli, Xenical), a weight-loss drug , can decrease the absorption of vitamin A. This can cause low blood levels of vitamin A in some people. Acitretin (Soriatane), used to treat psoriasi