BioStacks

Best Vitamin A for Immune

Top 10 products ranked

Last reviewed May 2026

Clinical dose: 700–1500 mcg

Why Vitamin A for Immune

Vitamin A plays a supporting role in immune. Exists as preformed retinol (animal sources) and provitamin A carotenoids like beta-carotene (plant sources). Retinyl palmitate and retinyl acetate are common supplemental forms with high bioavailability. In clinical studies, vitamin a enhances immune function.

What dose to look for

Clinical studies typically use 700–1500 mcg of vitamin a. Products below this range may not deliver meaningful results.

What the research says

Vitamin A has strong clinical evidence for immune benefits. Essential for vision via retinal pigment formation; toxicity risk above RDA in preformed retinol, not beta-carotene Learn more

Clinical research on Vitamin A

LOW — Essential for mucosal immunity but supplementation benefits limited to deficiency · 700–900 mcg RAE/day (from retinol or beta-carotene)

•Vitamin A is essential for maintaining mucosal barriers (respiratory, GI, urogenital tract) — the body's first line of immune defense. Deficiency dramatically increases susceptibility to respiratory and diarrheal infections.
•Cochrane review of vitamin A supplementation in children (43 RCTs, 215,633 children) found significant reduction in all-cause mortality and diarrhea incidence — but these were largely in deficient populations in developing countries. PubMed
•In non-deficient adults in developed countries, supplemental vitamin A provides no demonstrated immune benefit and carries toxicity risk. Hypervitaminosis A (>10,000 IU/day long-term) can cause liver damage and is teratogenic.

See full Immune research →