Dr David McGrath

Spine Physician

MB BS (Hons) FAFOM, RACP, FAFMM
Master of Pain Medicine

Vitamin K2

Bottom Line
1. Adequate intake vital for good health.
2. "vitamin K=K1" is not the same as K2
3. Activity and bioavailability of multiple forms of K2 (compared to MK-4 standard) unknown.
4. Other vitamins, i(eg vitA,D) ineffective unless adequate supplies. (the Activator vitamin)

Measurement
1. Not routinely available
2. Clotting factors used as inadequate proxy
3. Plasma osteocalcin (activated versus non activated ratio) can be used in some countries.

Chemistry
1.Class of compound called quinones. (similar reactions to peroxides)
2.Hetero/cyclic oxygen containing ring.

Variety
1. Multiple forms (vitamers or isomers) of K2, collectively called mena/quinones
2. Bacteria produce MK-7 to 10 (may be absorbed from GIT)
3. Mammals produce "mena/tetrenone" or MK-4 and also called "menaquinone-4"
4. Plants produce K1
5. Synthetic Vitamin K is called K3
6. Menaquinones MK4 to MK11 (MK-n n denotes the lengh of side chain)

Sources
1. Made be converted from K1 (Rich in green plants)
2. Organ meats (salivary glands, pancreas, testis, kidney,brain,mammary )
3. Also, bone,cartilage and vasculature
4. Fermented foods, acted upon by bacteria and yeasts.

Absorption
1.Dependant on adequate bile and pancreatic juices

Transportation
1. In Chylomicrons, VLDL,HDL

Actions
1. Synonomous with "activator X" of Weston A Price fame
2. Activates many proteins induced by the action of VitA and VitD

Physiology
1. Found in cytoplasm, at the endoplasmic reticulum (activator role)
2. Dense concentration in inner membrane mitochondria (energy regulation)
3. Nuclear receptor for Vit K identified. Very dense concentration. (gene expression)
4. Cofactor for carboxylase (gamma carboxylation of glutamate amino acid residues)
5. Possible role in energy regulation, gene expression and anti-oxidant redox regulation.
6. In liver K1, more active in converting clotting proteins.
7. In the brain K2 is higher in myelinated regions, and may play a role in myelination of nerve fibers. (associated with sphingo/lipids and sulphatides )
8. K2 is transported in the blood by the lipoprotein, apolipoprotein e (Apoe)
9. Deficient alleles of Apoe (ie Apo4 has reduced capacity to carry K2)
10. K2 also transported by HDL lipoprotein (protective for heart disease )
11. K2 widespread tissue distribution
12. K2 is recycled "Vitamin K cycle"
13. K2 is reportedly heat stable (ie resistant to cooking)

Deficiency
1. Poor mineralisation of bone and teeth (bone loss and fractures)
2. Poor immunolgy
3. Ectopic calcification of tissues (eg arteries) (risk of stroke and heart attack)
4. Chronic Fatigue
5. Learning Impairment
6. Seizures
7. Kidney Stones
8. Possible association with Alzheimers Demetia (Apoe4 association)

High Levels of K2
1. Reduce the risk of aortic atherosclerosis and MI (no relationship with K1)
2. Reduce the risk or growth of certain cancers (hepatocelular carcinoma)

Food Processing
1. Pateurization destroys K2
Some Identified Proteins activated by K2 (carboxylase )

ProteinFunction	Function
Bone Gla protein (BGP) Osteocalcin	Secreted by osteoblasts Activated to bind calcium and phosphate
Matrix Gla protein (MGP)	1. Mineralisation of bone,teeth 2. Prevents myocytes (SMC) from developing into osteoprogenitor/osteoblasts (inhibits Bone Morphogenic Protein-2; BMP-2) and thus prevents blood vessel calcification
Kidney Gla protein (KGP)	Kidney
Gas 6	Brain
Protein S	Immune System Protein expression
Trans-Membrane Gla Protein (TMG)	Unknown
Clotting Factors	Haemostasis (mostly K1 regulated)