Vitamin A (Retinol)

Specialist

also —

What it isRetinol is the preformed, active form of vitamin A, found in animal foods. The body also converts plant carotenoids (especially beta-carotene) to retinol, though inefficiently.

DoesDrives vision, epithelial cell turnover, immune, sperm production, and fetal development.

GoodAdequate retinol supports skin, vision, immune, and reproductive health.

BadDeficiency causes night blindness, impaired immunity, and skin problems. Excess (typically from chronic high-dose supplementation, not diet) causes hepatotoxicity, bone loss, and is teratogenic.

Standard

38–98 µg/dL.

Optimal

60–85 µg/dL (higher is good within range)

Modifiers

Fat-soluble — absorption requires dietary fat; falls with zinc deficiency.

How to optimize

Lifestyle: —
Diet: Liver (richest source), egg yolks, butter, full-fat dairy; carotenoid-rich plants (sweet potato, carrots, dark leafy greens) for conversion.
Supplements: Cod liver oil (provides A + D); discrete retinol supplements only with deficiency and monitoring.
Peptides: —
Drugs: Topical retinoids (tretinoin), oral isotretinoin for severe acne.

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