Phylloquinone Vitamin K: The Green Regulator, Clotting Conductor, Hepatic K1

Phylloquinone commonly known as Vitamin K is a plant-sourced, rapid-acting conductor of the clotting cascade, essential for life-saving coagulation while also playing a newly appreciated role in cardiovascular health by activating key bone and arterial proteins.

1. Overview:

Phylloquinone, or Vitamin K1, is the primary form of vitamin K found in plants. It is preferentially used by the liver to activate clotting factors (II, VII, IX, X) and proteins C & S, making it critical for proper blood coagulation. It also contributes to the activation of extra-hepatic proteins like osteocalcin in bone.

2. Origin & Common Forms:

Synthesized by plants for photosynthesis. Supplemental forms include standard phylloquinone and phytomenadione (a synthetic, water-soluble variant used in injections).

3. Common Supplemental Forms: Standard & Enhanced

· Phylloquinone (K1): The standard green-plant extract form, typically in softgels. It is the form used in most multivitamins and standalone K supplements.

· No significant "enhanced" forms exist for general use, as K1 is efficiently utilized by the liver for its primary clotting function.

4. Natural Origin:

· Sources: Green leafy vegetables are the quintessential source: kale, spinach, collards, broccoli, Brussels sprouts, and parsley. Content is directly proportional to chlorophyll content.

· Precursors: The plant synthesizes the naphthoquinone ring from precursors in the shikimate pathway.

5. Synthetic / Man-made:

· Process: Synthetic K1 (phytonadione) is produced via chemical synthesis, creating a molecule identical to the natural form. It is used in pharmaceuticals and some supplements.

6. Commercial Production:

· Precursors: Derived from petrochemical sources (like 2-methyl-1-naphthol) for synthesis.

· Process: Multi-step chemical synthesis followed by purification. For natural extracts, algae or alfalfa are processed and concentrated.

· Purity & Efficacy: Both synthetic and natural forms are fully effective. Synthetic phytonadione is the standard for medical reversal of anticoagulation.

7. Key Considerations:

The Warfarin Antagonist. K1 is the direct antidote to warfarin (Coumadin) overdose, as the drug works by inhibiting the vitamin K epoxide reductase (VKOR) enzyme, blocking the recycling and reactivation of K1. Patients on warfarin must keep their K1 intake consistent, not necessarily low.

8. Structural Similarity:

A naphthoquinone with a phytyl side chain. It differs from menaquinones (K2) by its side chain structure, which dictates its tissue distribution and kinetics.

9. Biofriendliness:

· Utilization: Absorbed in the small intestine with dietary fat, but absorption from plants is relatively low (~10-30%). Absorption is greatly enhanced when vegetables are cooked and consumed with fat.

· Metabolism & Excretion: Rapidly taken up by the liver for clotting factor synthesis. Not significantly stored; turnover is fast.

· Toxicity: Extremely low. No known toxicity from high oral doses, even in megadoses.

10. Known Benefits (Clinically Supported):

· Blood Coagulation: Prevents hemorrhage by ensuring functional clotting factors.

· Prevention of Vitamin K Deficiency Bleeding (VKDB) in newborns (hence the prophylactic injection at birth).

· Bone Health: Contributes to the activation of osteocalcin, supporting bone mineralization.

11. Purported Mechanisms:

· Co-factor for γ-Glutamyl Carboxylase (GGCX): This enzyme adds carboxylic acid groups to glutamate residues on "Gla proteins" (like clotting factors and osteocalcin), enabling them to bind calcium—an absolute requirement for their function.

12. Other Possible Benefits Under Research:

· Supporting cardiovascular health (though K2 is more studied for arterial calcification).

· Potential anti-inflammatory and antioxidant properties.

13. Side Effects:

· Minor & Transient: Virtually none at any dietary or supplemental dose.

· To Be Cautious About: Only for those on Vitamin K Antagonist Anticoagulants (Warfarin): Sudden, large changes in K1 intake can destabilize INR levels, increasing risk of clotting or bleeding.

14. Dosing & How to Take:

· Adequate Intake (AI): 90 mcg/day for women, 120 mcg/day for men.

· Supplemental Dose: Often 100-500 mcg in multivitamins or standalone formulas.

· How to Take: With a meal containing fat for optimal absorption.

15. Tips to Optimize Benefits:

· Diet First: A single serving of dark leafy greens (e.g., 1 cup cooked spinach) can provide over 500% of the AI.

· Synergistic Combinations: Healthy Fats: Consume greens with olive oil, avocado, or nuts.

· Form Choice: For general nutrition and clotting support, K1 is sufficient. For targeted arterial and bone health, a combination with K2 (MK-7) is often recommended.

16. Not to Exceed / Warning / Interactions:

· Drug Interactions: Warfarin (Coumadin): CRITICAL INTERACTION. Maintain consistent intake. Do not start or stop K1 supplements without medical supervision.

· Medical Conditions: Those with severe liver disease may have impaired clotting factor synthesis regardless of K1 status.

17. LD50 & Safety:

· Acute Toxicity (LD50): Not established; considered non-toxic.

· Human Safety: Exceptionally safe. No UL established.

18. Consumer Guidance:

· Label Literacy: Look for "Vitamin K1 (as Phylloquinone)" or "Phytonadione."

· Quality Assurance: Standard in reputable brands.

· Manage Expectations: It is an essential nutrient for blood clotting. Benefits for bone/heart are supportive and work best in the context of a diet rich in greens and adequate Vitamin D.