Vitamin K

Vitamin K
Vitamin name	Phylloquinone (K1), Menaquinone (K2)
Chemical formula	K1: C₃₁H₄₆O₂ / MK-4: C₃₁H₄₀O₂ / MK-7: C₄₆H₆₄O₂
Solubility	Fat-soluble
Discovery year	1930s (Nobel Prize 1943)
Daily requirement (RDA)	90–120 mcg
Upper limit
Rich food sources	K1: Well cooked leafy greens Recipe, milk, cheese, eggs K2: Hard cheeses, liver, egg yolks, dark chicken meat, grass-fed butter

Introduction

Vitamin K is a family of fat-soluble naphthoquinones essential for blood coagulation, calcium metabolism, and cellular energy production. The name derives from the German "Koagulation." While historically viewed as a single vitamin, K1 and K2 have distinct sources, tissue distributions, and biological activities. K2 is further subdivided into menaquinones (MK-4 through MK-13), with MK-4 and MK-7 being the most studied.

Structure/Chemical Properties

All vitamin K forms share a 2-methyl-1,4-naphthoquinone (menadione) ring structure. The difference lies in their side chains:

• K1 (Phylloquinone): Phytyl side chain; found in plants
• K2 (Menaquinones): Isoprenoid side chains of varying lengths
  • MK-4: 4 isoprenoid units (animal-derived or converted from K1)
  • MK-7 to MK-13: Longer chains (bacterial synthesis)
• K3 (Menadione): Synthetic, no side chain; banned for human use in the US due to toxicity

The quinone structure allows vitamin K to function as an electron carrier, similar to CoQ10.

Function/Mechanism of Action

"It has many effects, some of them prevent abnormal clotting, others abnormal bleeding, others favor energy production and brain lipid synthesis, calcium regulation." - Ray Peat

Vitamin K serves as a cofactor for gamma-glutamylcarboxylase, which activates vitamin K-dependent proteins (VKDPs) via carboxylation:

Function	Mechanism
Blood clotting	Carboxylates clotting factors (II, VII, IX, X) and anticoagulant proteins S and C in the liver
Bone mineralization	Activates osteocalcin, directing calcium into bone matrix
Soft-tissue decalcification	Activates Matrix Gla Protein (MGP), preventing arterial/kidney calcification
Energy production	Acts as alternative electron carrier, supporting CoQ10 function
Steroidogenesis	Facilitates cholesterol import into mitochondria for testosterone/progesterone synthesis
Insulin regulation	Activates ERGP protein in pancreatic beta-cells, regulating calcium flux and insulin secretion

Vitamin K is activated by carbon dioxide, adequate thyroid function and carbohydrate intake support this process.

Medical Uses/Effects

Indication	Evidence
Osteoporosis	MK-4 at 45 mg/day approved in Japan for treatment
Vascular calcification	10 mg every other day reversed arterial calcification in case studies
Blood pressure	Reduces vascular stiffness, lowering BP
Bleeding (aspirin users)	Protective when aspirin depletes K-dependent clotting proteins
Testosterone support	Restores youthful testosterone in elderly animals via steroidogenesis
Diabetes	Protects pancreatic beta-cells; inverse correlation with diabetes risk
Cancer	MK-4 in clinical trials for liver cancer (HCC), leukemias, myeloproliferative disorders
Dental health	Noticeable effects on oral hygiene and tartar reduction

Side/Adverse Effects

Vitamin K (natural forms) has an excellent safety profile:

• No established upper limit, insufficient evidence of toxicity even at high doses
• Japanese safety trials tested up to 135 mg/day MK-4 for one year with no side effects except mild GI upset
• Does not cause hypercoagulation in healthy individuals not on anticoagulants (K2 forms especially)
• K3 (menadione) is toxic, interferes with glutathione, causes liver damage; banned for human use

Drug interactions:

• Warfarin/anticoagulants: Vitamin K directly opposes their mechanism; requires careful management
• High-dose vitamin E: May increase bleeding risk; take vitamin K a few hours apart as protective measure

Dosing

Goal	Form	Dose
Basic maintenance	K1 or K2	100–200 mcg/day
Aspirin protection	K2	500 mcg–1 mg/day
Osteocalcin carboxylation (minimum)	MK-4	1 mg/day
Bone/muscle/brain benefits	MK-4	1–5 mg/day
Therapeutic (osteoporosis, calcification)	MK-4	10–45 mg/day
Weekly high-dose approach	MK-4	45 mg once weekly

Notes:

• Take with fat for absorption
• Olive oil is a preferred vehicle; avoid MCT oil orally (topical use acceptable)
• MK-7 has longer half-life (~72 hours) vs MK-4 (shorter), affecting dosing frequency

Positive interactions:

Vitamin K2 guides calcium to the bone and teeth while also removing it from arterial plaque.

Brands and sources

Brand/Product	Form	Notes
Thorne Research K2 Drops	Liquid MK-4	Ray Peat directly recommended; 1 mg per drop; mentioned in multiple interviews as the go-to
IdeaLabs Kuinone	Liquid MK-4 (2 mg/drop)	Dissolved in SFA esters + ethanol or olive oil (EVOO option available); created as cheaper alternative to Thorne
IdeaLabs EstroBan	Combo (K2 + A + D + E)	MK-4 with other fat-solubles for synergy
Life Extension MK-4	45 mg capsules	Mentioned in forum discussions for high-dose protocols

Ray Peat's leafy greens recipe