Vitamin K2

Vitamin K2

Carboxylation reaction - 'Vitamin K cycle'

Vitamin K2, also known as the menaquinones, represents an important group within the Vitamin K family. Distinct from its counterpart Vitamin K1, which is primarily found in leafy greens and plays crucial roles in blood clotting, Vitamin K2 is renowned for its role in bone health and arterial health. Menaquinones can be subdivided based on the length of their side chain, with both short-chain and long-chain variants offering distinct health benefits.

Chemical Classification and Structure

The defining difference between the various menaquinones is the length of their isoprenoid side chains. These side chains can vary in length from 4 to 13 isoprene units. The specific number of isoprene units is typically denoted by "MK-n", where "n" represents the number of these units.

Types of Vitamin K2

Short-chain Menaquinones:

• • MK-4: The most studied of the short-chain menaquinones. It is believed to be synthesized by certain animals from Vitamin K1 and can be found in animal-based foods like meat and eggs.

Long-chain Menaquinones:

• • MK-7: This form is particularly abundant in fermented foods, notably the Japanese dish natto.
  • MK-8 and MK-9: Often derived from dairy-based sources and fermented foods. The longer side chain increases their bioavailability and half-life in the human body compared to MK-4.

Physiological Roles

Vitamin K2 is integral to several physiological processes:

• Bone Health: Collaborates with Vitamin D and calcium to promote bone mineralization, thereby contributing to overall bone strength.
• Arterial Health: Inhibits calcification in arteries and soft tissues. This action ensures arterial flexibility and health.
• Blood Coagulation: While Vitamin K1 is more active in coagulation processes, K2 also plays a role in ensuring proper clotting.

Dietary Sources and Supplementation

Vitamin K2 is found naturally in a variety of foods:

• Fermented foods like natto and certain cheeses.
• Animal-based foods like liver, meat, and egg yolks.
• Dairy products, especially hard cheeses.

Vitamin K2 supplements are also available for those deficient in this nutrient or for those seeking to ensure an adequate intake.

Deficiency

A deficiency in Vitamin K2 can lead to:

Impaired bone health and increased risk of bone fractures. Arterial calcification, increasing the risk of cardiovascular diseases.

Conclusion

Vitamin K2, with its various subtypes, plays crucial roles in human health. Ensuring adequate intake, whether through diet or supplementation, is vital for maintaining optimal bone and cardiovascular health.

See Also

• Vitamin K1
• Bone Health
• Cardiovascular Diseases
• Nutrition

External links

• Vitak BV - a research company with a long expertise in all aspects of vitamin K and vitamin K-dependent proteins.
• VitaminK2.org - an International Community founded to explore and understand the emerging role of Natural Vitamin K2 in human health.