What is the recommended dosage for Vitamin A?

General: 700-900 mcg RAE/day; Immune Support: 900 mcg RAE/day

What are the side effects of Vitamin A?

Potential side effects include: Hepatotoxicity at chronic high doses, Birth defects (teratogenic at high doses during pregnancy), Nausea and headache, Bone density reduction with long-term excess.

What is vitamin A and how does it support immune function?

Vitamin A is a fat-soluble vitamin essential for maintaining mucosal barriers (skin, respiratory tract, gut lining) and supporting the development and function of immune cells including T-cells and B-cells. It is sometimes called the 'anti-infective vitamin.'

What dosage of vitamin A has been studied for immune health?

The recommended dietary allowance for adults is 700–900 mcg RAE per day. Clinical studies for immune outcomes have used doses up to 3,000 mcg RAE per day. The Tolerable Upper Intake Level is 3,000 mcg RAE per day for adults due to toxicity risk.

What are the potential side effects of vitamin A supplementation?

Excess preformed vitamin A (retinol) can cause nausea, headache, liver damage, and birth defects. Chronic intake above the upper limit is toxic. Beta-carotene (provitamin A) is generally safer but may increase lung cancer risk in smokers at high doses.

Vitamin A

vitamin

Also known as: Retinol, Retinyl Palmitate, Beta-Carotene (provitamin A)

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About

Vitamin A supports mucosal barrier integrity in the respiratory and gastrointestinal tracts and regulates cell-mediated immunity, cytokine production, and lymphocyte trafficking to mucosal surfaces. Known as the 'anti-infective vitamin,' deficiency is strongly associated with increased susceptibility to infectious diseases.

How It Works

Supports mucosal barrier integrity in respiratory and GI tracts; regulates cell-mediated immunity, cytokine production, and lymphocyte trafficking to mucosal surfaces.

Evidence For Conditions

Condition	Grade	Studies	Participants
Pediatric Immune Support	B	10	5000	View →

Side Effects

Hepatotoxicity at chronic high doses
Birth defects (teratogenic at high doses during pregnancy)
Nausea and headache
Bone density reduction with long-term excess

Drug & Supplement Interactions

Retinoid medications (additive toxicity risk)
Orlistat (reduces absorption of fat-soluble vitamins)
Alcohol (increases hepatotoxicity risk)
Tetracycline antibiotics (increased intracranial pressure risk)

Always inform your healthcare provider about all supplements you take.

Related Ingredients

Vitamin B6 Vitamin C Vitamin D Vitamin E

Quick Facts

Dosage: General: 700-900 mcg RAE/day; Immune_Support: 900 mcg RAE/day
Forms: capsule softgel liquid
Natural Sources: Liver, Sweet potatoes, Carrots, Spinach, Kale, Eggs
Upper Limit: 3,000 mcg RAE/day (preformed vitamin A)
Best Time: With meals containing fat

Evidence Summary

Pediatric Immune Support B

FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. The products and information on this website are not intended to diagnose, treat, cure, or prevent any disease. The evidence grades presented are based on our analysis of published peer-reviewed research and do not constitute medical advice. Always consult your healthcare provider before starting any supplement regimen.