Vitamin A (retinol, low-dose)

Tier 2 — promising · Vision · Immunity · Skin

Essential for night vision, immune function, and cell growth. Deficiency affects 190 million children worldwide, causing preventable blindness. Retinol from animal sources absorbs well; plant beta-carotene converts variably. Fat-soluble and accumulates in the body — never exceed 3,000 mcg RAE/day. High doses cause liver toxicity and birth defects.

Dose: 700–900 mcg RAE/day; do NOT exceed 3,000 mcg RAE/day from supplements; avoid high-dose retinol in pregnancy