Vitamin K is one of 13 essential vitamins and minerals the body requires to maintain general health and wellbeing. The body requires vitamins and minerals for immune and gut health, bone and joint strength, cell regeneration and more.
Many of these vitamins
can be incorporated through a healthy, balanced diet. Here’s what you need to know about vitamin K1 and K2, from the basics to the benefits and recommended food sources.
1. The basics: what is vitamin K
Vitamins are categorised into two groups: water-soluble or fat-soluble. Vitamin K is not a single vitamin, but a group of related fat-soluble vitamins. This group includes a compound called phylloquinone, also known as vitamin K1, and a series of menaquinones which are commonly referred to as vitamin K2.
2. What are the benefits?
Vitamin K is a trace nutrient essential for the normal function of several proteins in the body. These proteins have very specific roles that are needed for human health.
Our bone strength can weaken with age so consuming vitamin K2 through dietary sources is important. Vitamin K2 is involved in the body’s ability to produce, and maintain normal healthy bones, through its role in the formation osteocalcin - a protein produced in bone matrix. Osteocalcin binds with calcium and results in calcium being deposited into bones and bone mineralisation.
Deficiency is rare but a lack of vitamin K could lead to weaker bones and increase the risk of getting bone fractures. Osteoporosis Australia highlights emerging research in women who have been through menopause (a high risk group for developing osteoporosis) showed an increase in bone strength and a slower rate of bone weakening with the addition of vitamin k2 supplements. While research is still ongoing, it is encouraging
Vitamin K is essential for several proteins involved in blood coagulation, a function the body requires to prevent excess bleeding. These vitamin K dependant blood-clotting factors form the ‘coagulation cascade’ which helps our blood to coagulate and stop us from bleeding excessively
Vitamin K food sources
3. What’s the difference between vitamin K1 and K2?
While they are related, there are many differences between vitamin K1 and vitamin K2. T heir chemical structure, the function they have in the body and how they are metabolised are different.
In addition, the food sources they can be found in are different. Vitamin K1 is found in plant based foods whereas vitamin K2 is commonly found in dairy and meat sources. After absorption Vitamin K1 is stored in the liver, and used to make clotting factors.
However, vitamin K2 is packaged into lipoproteins and released into the bloodstream, where it then travels to the bones.
4. Vitamin K1 and K2 Foods
Our bodies produce about half of the required intake of vitamin K naturally through intestinal bacteria. We need to supplement this through diet to ensure the recommended daily requirement.
Vitamin K1 is found in green leafy vegetables
such as spinach, broccoli, Brussels sprouts, Swiss chard and kale.
Vitamin K2 is primarily bacterial in origin and found in animal-based foods, such as cheese, cheese curd, fermented foods, egg yolk, whole milk, and in particular Natto (a traditional Japanese fermented soy bean food). In addition, it is found in fatty meats and liver.
For maximum benefits and to increase absorption, it is recommended to cook foods high in vitamin K in fat or oil as they are fat-soluble.