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Vitamin

Vitamin A (Retinol)

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Vitamin A (Retinol). Fat-soluble vitamin essential for vision, immune function, and epithelial integrity.

How it works. Binds retinoic acid receptors (RAR/RXR) regulating gene transcription; rhodopsin precursor in retina.

What the research supports. 2 graded claims. Strongest: Prevents xerophthalmia / night blindness (strong).

How much to take. Typical dose: 700–900 mcg RAE.

Side effects and interactions. 2 medication interactions listed. Serious: Hepatotoxicity & birth defects at >10,000 IU/d chronically.

Stacking. Pairs well with Vitamin D3 + K2, Zinc, Collagen peptides. Avoid combining with Pregnancy (high-dose retinol).

Common forms. Available as Retinol, Retinyl palmitate, Beta-carotene (provitamin).

Key studies. 9 studies cited. The strongest are listed with links to PubMed.

Community. Experiences from people who have tried Vitamin A (Retinol). Anecdotes are not medical advice.

Vitamin A (Retinol). Fat-soluble vitamin essential for vision, immune function, and epithelial integrity.

Molecular structureC20H30O · 286.5 g/mol

What it is

Fat-soluble vitamin essential for vision, immune function, and epithelial integrity.

Also called

RetinolRetinyl Palmitate

Food sources

LiverEgg yolkButterCod liver oil

Goals

Eye HealthImmune FunctionSkin, Hair & NailsGeneral Wellness

How it works

Binds retinoic acid receptors (RAR/RXR) regulating gene transcription; rhodopsin precursor in retina.

Pathways

  • RAR/RXR signaling
  • Visual cycle

Effects

  • +Night vision supports
  • +Mucosal immunity supports

What the research supports

Prevents xerophthalmia / night blindnessstrong
Reduces measles mortality in deficient childrenstrong

Strong: consistent results across large trials or meta-analyses. Moderate: several trials, mostly positive. Limited: small or mixed studies. Preclinical: animal or cell research only.

Typical dose
700–900 mcg RAE
TimingConsistent daily timing recommended; split larger doses if GI tolerance is a concern.
With foodYes (fat-soluble)
Best formMixed with food
Upper limit3,000 mcg RAE
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Side effects & interactions

Serious

  • Hepatotoxicity & birth defects at >10,000 IU/d chronically

Medication interactions

Isotretinoin / Acitretinsevere

Additive vitamin A toxicity.

Warfarinmoderate

May potentiate at high doses.

Check any supplement–medication combination with your pharmacist before starting.

Combines with

Pairs well

  • Vitamin D3 + K2Foundational immune modulation.
  • ZincRequired cofactor for innate and adaptive immune function.
  • Collagen peptidesProvides amino acid substrate for connective tissue synthesis.

Avoid combining

  • Pregnancy (high-dose retinol)Teratogenic above ~10,000 IU/day.

Common forms

  • Retinol
  • Retinyl palmitate
  • Beta-carotene (provitamin)

Key studies

9 studies cited in total.

PubMed: Vitamin A (Retinol) — Prevents xerophthalmia / night blindness ↗
Systematic review · PubMed (NLM) · 2026

Opens current human and preclinical literature matching Vitamin A (Retinol) and "Prevents xerophthalmia / night blindness". Filter by RCT, meta-analysis, or year on the results page.

PubMed: Vitamin A (Retinol) — Reduces measles mortality in deficient children ↗
Systematic review · PubMed (NLM) · 2026

Opens current human and preclinical literature matching Vitamin A (Retinol) and "Reduces measles mortality in deficient children". Filter by RCT, meta-analysis, or year on the results page.

PubMed: Vitamin A (Retinol) — randomized controlled trial ↗
Systematic review · PubMed (NLM) · 2026

Opens current human and preclinical literature matching Vitamin A (Retinol) and "randomized controlled trial". Filter by RCT, meta-analysis, or year on the results page.

Discussion

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