What it does to your body (the real physiology)
1) Blood + oxygen delivery = higher output
- Iron is a core part of hemoglobin (oxygen transport) and supports muscle metabolism.
- Vitamin B12 supports normal red blood cell formation and deficiency can cause anemia + neurological issues.
- A typical USDA “slice” of pan-fried beef liver (81 g / ~3 oz) contains ~5.0 mg iron and ~67.34 µg B12 —that’s massive for performance physiology.
2) Nervous system + brain signaling = sharper wiring
- Choline is needed to make acetylcholine (key neurotransmitter for memory, mood, muscle control) and supports cell membranes + lipid transport/metabolism.
- Pair that with B12’s role in neurological health and you’ve got serious “hardware support.”
3) Energy metabolism = mitochondria get fed
- Riboflavin (B2) forms key coenzymes (FMN/FAD) used in energy production pathways.
- Beef liver is also a strong B6 source—USDA lists ~0.832 mg per 81 g slice.
4) Vision + immunity + skin renewal = “vitamin A nuclear fuel”
- Preformed vitamin A is highest in foods like liver, and your body stores it largely in the liver.
- The USDA list shows that same ~81 g slice has ~21,131 IU vitamin A.
5) DNA / cell division / methylation support
- Folate supports DNA/RNA synthesis and cell division (foundational biology).
- Liver tends to stack folate + B12 + choline—three pillars in “build/repair” metabolism.
6) Enzyme power + connective tissue support
- Copper is required for many enzymes; organ meats are among the richest sources.
The one big “respect this” rule (don’t overdo it)
Vitamin A is fat-soluble, stored, and can accumulate.
- The adult UL for preformed vitamin A is 3,000 mcg RAE/day.
- Vitamin A IU conversion (for retinol) is 1 IU = 0.3 mcg RAE, so that ~21,131 IU serving can be ~6,300 mcg RAE (very roughly)—over the daily UL if you did that every day.
Practical move: treat liver like a potent “dose food.” Many people keep it to ~2–4 oz once a week (or smaller portions 1–2x/week), not daily—especially if you also take a multivitamin with vitamin A.
Who should be extra careful
- Pregnant / trying to be pregnant: high preformed vitamin A can be risky; ODS explicitly warns against high-dose vitamin A in this context.
- Hemochromatosis / iron overload risk: some people are prone to excess iron.
- Copper-handling disorders (e.g., Wilson’s): copper excess can be harmful.
If you want, tell me your goal (energy, strength, skin, fixing low iron/B12, etc.) and I’ll give you a simple liver protocol (portion + frequency + “don’t accidentally megadose vitamin A” setup).