Difference Between Vitamin K and K2

The main difference between vitamin K and K2 is that the vitamin K is a group of vitamins having a well-known role in blood clotting, heart health, and bone health whereas vitamin K2 is one of the two main forms of vitamin K, which is most abundant in fermented foods and some animal products. Furthermore, vitamin K1 is the other main form of vitamin K which is mainly found in plant sources.

Vitamin K and vitamin K2 are two forms of important vitamins that are fat-soluble. Hence, vitamin Ks are efficiently absorbed when consumed with dietary fat.

Key Areas Covered

1. What is Vitamin K
     – Definition, Forms, Health Benefits
2. What is Vitamin K2
     – Definition, Sources, Facts
3. What are the Similarities Between Vitamin K and Vitamin K2
     – Outline of Common Features
4. What is the Difference Between Vitamin K and Vitamin K2
     – Comparison of Key Differences

Key Terms

Blood Clotting, Fat Soluble, Vitamin K, Vitamin K1, Vitamin K2

What is Vitamin K

Vitamin K is a group of vitamins that play a critical role in blood clotting. The three forms of vitamin K are vitamin K1, K2, and K3. All of them comprises a similar structure and are fat-soluble. However, the two main forms of vitamin K are vitamin K1 (phylloquinone) and K2 (menaquinone). The predominant form of vitamin K in the diet is vitamin K1, which is produced by plants. Some rich sources of vitamin K1 include leafy green vegetables such as kale, collard greens, spinach, turnip greens, broccoli, and Brussels sprouts. The main difference between vitamin K1 and K2 is their absorption; less than 10% of the K1 can be absorbed by the body.

Figure 1: Sources of Vitamin K 

Vitamin K is important for blood clotting and the health of the heart and bones. Vitamin K-related modifications in the blood clotting proteins allow the binding of calcium ions to them, which is critical in the blood clotting process. Also, vitamin K prevents the deposition of calcium inside blood vessels. Vitamin K also activates proteins involved in the growth and the development of bones. Though vitamin K deficiency is rare, individuals with severe malabsorption or malnutrition or those who take warfarin can have vitamin K deficiency, characterized by excessive bleeding.

What is Vitamin K2

Vitamin K2 is one of the main forms of vitamin K found in fermented food and animal products. Some amount vitamin K2 is produced by the bacteria in the gut. Subtypes of vitamin K2 vary from MK-4 to MK-15. The two main subtypes of vitamin K2 are MK-4 and MK-7. MK-4 is found in animal products and is not produced by bacteria. Good sources of MK-4 are chicken, egg yolk, and butter. MK-5 to MK-15 are produced by bacteria; hence, they are found in fermented food. MK-4 contains short side chains while bacterial MKs have long side chains. Due to these side chains, they can exist in the circulation for a considerable time period, facilitating the absorption by various parts of the body.

Figure 2: Vitamin K Types

Similarities Between Vitamin K and Vitamin K2

• Vitamin K and K2 are two fat-soluble vitamins.
• They play a vital role in blood clotting and are important in heart and bone health.

Difference Between Vitamin K and Vitamin K2

Definition

Vitamin K refers to any of a group of vitamins essential for the blood-clotting process while vitamin K2 refers to one of the K vitamins found in cabbage, spinach, and other leafy green vegetables.

Correspondence

The three forms of vitamin K are vitamin K1, vitamin K2, and vitamin K3 while the subtypes of vitamin K2 vary from Mk-4 to MK-15.

Sources

Green leafy vegetables are a good source of vitamin K1 while vitamin K2 is available in animal sources and fermented food.

Absorption by the Body

While Vitamin K1 is poorly absorbed by the body, a higher percentage of vitamin K2 is absorbed by the body. Therefore, this is the main difference between vitamin K and vitamin K2.

Fate in the Body

Vitamin K1 is transported to the liver while vitamin K2 circulates in the blood for several hours.

Conclusion

Vitamin K is a group of vitamins important in blood clotting, bone and heart health. On the other hand, vitamin K2 is a form of vitamin K found in animal products and fermented food. The most absorbing form of vitamin K is vitamin K1, which is found in leafy green vegetables. The main difference between vitamin K and vitamin K2 is their absorption.  

Reference:

1. “ Vitamin K1 vs K2: What’s the Difference?” Healthline, Healthline Media, Available Here

Image Courtesy:

1. “vegetables-broccoli-lettuce-white-490685” (CC0) via Pixabay
2. “Phylloquinone structure” By User:Mysid – Self-made in BKChem + perl + vim. (Public Domain) via Commons Wikimedia      
3. “Menaquinone” By Calvero. – Selfmade with ChemDraw. (Public Domain) via Commons Wikimedia