Vitamin K1 (Phylloquinone)

维生素 K1 · 凝血的钥匙

Place · Level 3 · Vitamin

绿叶里的凝血因子激活剂 · γ-羧化让 II/VII/IX/X 抓住钙 · 新生儿出血预防 · 华法林为何要稳

Connected to · 2

antagonism · 1

Vitamin E
High-dose vitamin E (>800 IU/day) interferes with γ-carboxylation of K1-dependent clotting factors (II/VII/IX/X) → bleeding risk. Particular concern with warfarin/DOAC or recent surgery. Dietary doses (~15 mg/day) are fine.

contrast · 1

Vitamin K2
Same naphthoquinone core, all the difference is in the tail: K1 goes to the liver to activate clotting factors II/VII/IX/X, K2 runs the osteocalcin and MGP route that decides where calcium ends up. One digit apart in the name, different jobs entirely.

K1 lives in leaves

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K1 在叶子里

Vitamin K1 (phylloquinone) is part of the chloroplast machinery in plant leaves, where it participates in photosynthetic electron transport. The greener the leaf, the higher the K1:

Kale, cooked, 100 g: ~820 µg — the leaderSpinach, cooked, 100 g: ~540 µgBroccoli, cooked, 100 g: ~140 µgLettuce (large leaf), 100 g: ~50-100 µgSoybean / canola oil: moderate amounts — one of the main K1 sources in Western diets
AI (Adequate Intake, IOM) targets: 120 µg/day men, 90 µg/day women — a single cup of cooked spinach exceeds the daily target.

K1 vs K2 division of labor: K1 mainly serves the liver, activating clotting factors II / VII / IX / X; K2 takes the osteocalcin + MGP path (see the Atlas vitamin-k2 story). Structurally the head is the same (naphthoquinone core); the difference is in the tail — K1 has a single isoprenoid side chain, K2 has multiple (MK-4 to MK-13). The body can interconvert small amounts of K1 → MK-4, but not enough to cover the full range of K2 functions.

'I eat greens daily, I shouldn't be K1-deficient' is essentially correct — this is one of nutrition teaching's rare 'if the diet structure is normal, you're covered' cases. Real K1 deficiency occurs in: long-term TPN (parenteral nutrition), severe fat malabsorption, long-term broad-spectrum antibiotic use, anticonvulsant use, and newborns (see later scene).

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Educational content, not medical advice — consult a clinician.

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