Also known as: Retinol, Beta-carotene, Retinyl palmitate
Latest evidence update: 2026-03-01
Strongest in Sample size (95). Held back by Recency (17).
Solid mix of RCTs with some methodological gaps.
Confirmed across many independent studies with significant findings.
Tens of thousands of participants pooled across studies.
Mostly aligned, with some divergence.
Mostly pre-2020 research; updates may be needed.
Effect-size tagged on 390 of 400 claims for this supplement. The corpus updates daily; remaining claims are pending re-processing.
Recommended: Varies by form and individual needs
ProtocolEngine provides general health information based on published research. This is not medical advice. Consult a healthcare professional before starting any supplement or health protocol.
Reduces childhood mortality and prevents blindness from vitamin A deficiency in children under five years old
Lowers risk of measles illness and may reduce preterm birth in healthy pregnant women
Reduces periodontitis risk and may lower stroke risk
High intake of vitamin A from supplements is associated with increased risk of hip fractures and bone breaks
Shows no clear benefit for preventing upper respiratory infections, colorectal cancer, breast cancer, or reducing HIV disease progression