Top 5 Vitamin K Benefits and the Best Sources
Vitamin K, and in particular vitamin K2, has received a lot of interest in recent years due to a greater understanding of its role in the body and its many potential health benefits.
Once believed only to be important for blood clotting, and deficiencies in it rare, we now know that vitamin K has a vital role in preventing serious health issues like cardiovascular disease, osteoporosis and possibly even certain cancers.
What has also emerged is that the K2 version of vitamin K, also known as menaquinones, is likely to be far more important for good health than vitamin K1. Unfortunately, this is the type of vitamin K you're most likely to be deficient in.
This page will cover five good reasons to get more vitamin K into your diet. With the exception of proper blood clotting, these vitamin K benefits are believed to be primarily attributed to the K2 version of the vitamin.
To read more about the difference between vitamin K1 and vitamin K2 see the page on Vitamin K Deficiency and How to Avoid It.
5 Health Benefits of Vitamin K
1. Vitamin K protects your bones and reduces the risk of osteoporosis.
Without adequate levels of vitamin K in your body, calcium regulation is impaired with often very damaging long-term consequences.
Vitamin K helps keep calcium and other minerals in your bones by maintaining osteocalcin levels. Osteocalcin is a protein secreted by osteoblasts in your bones to bind minerals to the bone matrix. However, when vitamin K (and is believed particularly vitamin K2) is not present in sufficient quantities then osteocalcin cannot perform this function.
This leads to calcium been lost from bones at an increased rate. Over time, brittle bones and crippling osteoporosis are the result.
Ahead I’ll list some of the best food sources of vitamin K2, but anyone at risk of osteoporosis might consider looking into a good vitamin K2 supplement based on fermented natto, the highest natural source.
2. Prevent arterial calcification that leads to atherosclerosis and heart disease.
When calcium is leaching out of your bones due to low vitamin K levels, the excess can be deposited in the cardiovascular system and particularly the arteries.
Maintaining good levels of vitamin K in your body is necessary for the formation of a special protein called matrix GLA protein (MGP). MGP helps to block calcium crystal formation inside your blood vessels, but it requires vitamin K to function correctly.
People with a vitamin K deficiency have been found to have a higher risk of hardening arteries and this study found vitamin K2 menaquinone specifically associated with a reduced risk of coronary calcification.
3. Proper blood clotting and less bruising.
Your liver manufactures blood clotting proteins and vitamin K is required for this to happen.
These blood clotting proteins also affect how easily you bruise and how quickly bruises heal. Frequent bruising may indicate a need for more vitamin K in your diet.
While the formation of blood clotting proteins is a vital process, the belief that this was vitamin K's primary function lead to dietary intake recommendations based only on enough vitamin K for this purpose.
Vitamin K's role in bone building, cardiovascular health and the other benefits of vitamin K listed ahead have many health experts saying the RDA for vitamin K is inadequate. Some also believe any revision needs to recognize vitamin K2 specifically.
It's important to know that blood thinning medications like Warfarin work by disrupting vitamin K’s function, so if your doctor has prescribed these you need to consult with them before increasing vitamin K in your diet, especially through supplements.
4. Reduced cancer risk.
Vitamin K2 in particular is being studied for potential protective effect against certain cancers. A large European study of more than 11,000 men over nearly 9 years found a reduced risk of prostate cancer with a higher intake of vitamin K2 (though not vitamin K1).
Another smaller study found vitamin K2 had a significant preventative effect against liver cancer in women with viral cirrhosis of the liver. Other studies have examined treating leukaemia cells and other haematological cancers with menaquinones.
5. Improve your skin and prevent wrinkles.
The same calcification problems that harden arteries can also affect the connective elastin that keeps your skin soft and subtle. Without adequate vitamin K in your diet, calcium can be deposited in your skin’s elastin fibers and harden to cause wrinkles.
Vitamin K is also needed for the formation of certain proteins that maintain healthy skin cells and it may be a factor in skin problems like acne. In fact, there are many reports of topical vitamin K skin treatments helping to prevent acne and in particular heal skin affected by acne scarring.
And here's a video showing the top 20 vegetables high in vitamin K.
Vitamin K1 and K2 Sources
Vitamin K1 is primarily found in green leafy vegetables like kale, romaine lettuce, spinach, Swiss chard, collard greens, brussel sprouts, broccoli and cabbage.
While it's definitely good to get plenty of these type of greens in your meals (they have many other health benefits) the conversion from vitamin K1 the K2 in your body is now believed to be quite ineffective at around 10 to 1. Having some healthy fats with your greens can help improve this ratio, but clearly there are good reasons to get more vitamin K2 specifically into your diet.
The Japanese fermented soy dish natto is usually recognized as the best food source of vitamin K2. It is also primarily the longer lasting MK-7 version of the vitamin. Japanese people eat a lot of this food and it is speculated that this is why they have a much lower incidence of hip fractures and osteoporosis than people in the USA or Europe.
Unfortunately, natto is not often compatible with Western tastes, but you can get it in concentrated supplemental form and take one a day to get the same vitamin K2 benefits.
Other sources of vitamin K2 are fermented foods like sauerkraut, kefir and certain hard cheeses like emmental and Swiss cheese.
Liver, kidney and other organ meats, egg yolks from free range chickens, grass fed meats and particularly grass fed butter are also sources of vitamin K2.
Were you aware of the health benefits of vitamin K and have you tried increasing it in your diet? I’d be interested to hear of your results, particularly with natto or natto supplements and how you found using them.
Here's a related infographic from bengreenfieldfitness.com