I don’t think K2 is necessarily being left out of the vitamin crowd, but I do believe its popularity is about to skyrocket. K2 is poised to become a major player in the health world, and after today, you’ll see why.
Get to Know Vitamin K
Vitamin K’s been around for a pretty long time; it was discovered in Germany in 1929.
Its abbreviation comes from the German word koagulation (coagulation) because it was initially identified as an essential factor for blood coagulation.
Our livers need vitamin K to produce blood clotting proteins. People at risk for blood clots take prescriptions (such as Coumadin) that intentionally block vitamin K and suppress blood clot formations because they can cause strokes and heart attacks.
Vitamin K is considered an essential vitamin and is categorized with other fat soluble vitamins such as A, D, and E. This means that you need to consume vitamin K (whether from diet or supplement form) with a bit of fat to aid the absorption.
However, our bodies don’t devote much storage room for vitamin K so if we’re not regularly consuming it, we can actually recycle it.
This process is known as the vitamin K cycle.
What’s the Difference Between Vitamins K, K1, and K2?
These aren’t necessarily different vitamins, but parts of the same whole. Vitamin K breaks down into two main forms, also called vitamers:
- K1 (phylloquinone): found in plant sources
- K2 (menaquinone): found in animal and fermented food sources
And to make matters more complicated, vitamin K2 breaks down even further into the subtypes MK-4, MK-7, MK-8, and MK-9.
These numbers all indicate the number of side chains in the molecular structure of the vitamin, for example, there are four in MK-4.
Vitamin K is most responsible for triggering the calcium-binding nature of proteins.
However, the main difference between K1 and K2 is function.
K1 is mainly involved in helping the liver activate proteins to bind to calcium during blood clotting.
K2, on the other hand, helps facilitate the transport and absorption of calcium so our bodies can use it. It activates different vitamin K-dependent proteins to steer calcium away from our arteries and towards our bones.
In fact, vitamin K2 has been shown to be a more important factor in bone health and strength than K1. And that’s just one great benefit.
The Benefits of Vitamin K2
Vitamin K2 has shown significant evidence that it can help take on osteoporosis and cardiovascular disease, two of the most common causes of death worldwide.
Strengthen Bones and Lower Your Osteoporosis Risk
Ladies, listen up! Here are some eye-opening facts from the National Osteoporosis Foundation:
- Of the estimated 10 million Americans with osteoporosis, about eight million or 80% are women.
- Approximately one in two women over age 50 will break a bone because of osteoporosis.
- A woman’s risk of breaking a hip is equal to her combined risk of breast, uterine, and ovarian cancer.
So what can you do to outsmart your biology and keep your bones strong?
Vitamin D is typically the vitamin when we’re talking about bone health, so it’s often prescribed as a supplement to strengthen bones and prevent osteoporosis.
However, having an excess of vitamin D can lead to artery hardening.
When vitamin K and vitamin D, aka the sunshine vitamin, work together they achieve fantastic results.
See, vitamin K helps remove the excess calcium from your blood so you are less likely to experience the downsides of vitamin D.
According to one study, when K2 and vitamin D were taken together by postmenopausal women, their bone mineral density (BMD) increased.
What’s even better is that K2 has been shown to maintain healthy levels of bone mineral density on its own.
Specifically, vitamin K2 jumpstarts the calcium-binding activity of two important proteins, Matrix gla protein (MGP) and osteocalcin. These two have been studied for their help in building and maintaining bone strength.
During one study, researchers gave 325 postmenopausal women a placebo or 45 mg/day of vitamin K2 (more specifically, MK-4). They measured the women’s bone density and bone mineral content (BMC) over the course of three years.
The results demonstrated that these relatively high doses of vitamin K2 were essential for improving bone mineral content and preventing postmenopausal bone loss.
On K2, BMC increased and hip bone strength remained the same. K2 even reduced the occurrence of spinal fractures by 52% in patients with osteoporosis.
However, the women taking the placebo had a significant decrease in their hip bone strength and did not reduce their risks of fractures.
Japanese women have very high levels of bone mass density. Scientists believe this is attributed to their typical consumption of natto, a fermented soybean dish, which falls in the K2 realm.
These women have very low instances of osteoporosis and bone fractures, which leads to the theory that the increase in K2 from natto’s MK-7 “may help prevent postmenopausal bone loss.”
Conversely, hip fractures are more common in areas of the country that don’t eat natto regularly.
So it would seem as if having appropriate levels of K2’s MK-7 is an indicator of BMD.
To test this, scientists from another study gave 244 healthy postmenopausal women 180 mcg of MK-7 or a placebo daily for three years.
They discovered that both BMC and BMD, as well as bone strength, were “statistically significantly better” for the women taking the MK-7 compared to the placebo group.
According to animal studies on osteoporosis, vitamin K2:
- Improves bone structure
- Increases bone mass
- Enhances bone strength
- Stimulates calcium deposits
- Boosts collagen architecture (cross-linking of fibrous tissue that creates strong, yet supple bones that are more resistant to fracturing)
As we can see, the evidence on vitamin K2’s role in preventing osteoporosis is pretty compelling.
Help Preventing Heart Disease
When you compare osteoporosis with heart disease you can spot a few similarities.
Both conditions manifest later in life, when you’re in your 50s–70s, and require years to develop.
In fact, they even have many of the same risk factors:
- Sedentary lifestyle
- High cholesterol
This comparison led scientists to theorize that the same factors may be influencing both the health of our bones and the health of our arteries.
Dr. Linda Demer from UCLA was among the first to identify a protein called bone morphogenetic protein-2 in atherosclerotic tissue, which is built-up plaque in your arteries.
This protein was previously understood to only reside in bone tissue as it plays a large role in bone formation.
But after this discovery, other recognizable bone-forming factors were also found in atherosclerotic plaque tissue.
Vascular calcification, or a buildup of calcium in the blood vessels, was renamed vascular ossification.
This is how osteoporosis and heart disease are connected; it’s called the “Calcium Paradox.”
If there’s a lack of calcium in your bones, there can also be an excess of calcium in your arteries.
However, let’s not forget about vitamin K.
Vitamin K works to remove these calcium ions in your blood to make sure they don’t build up in your arteries and cause them to harden.
As you can expect, having low levels of K2 has been associated with increased risks for atherosclerosis, or artery hardening, and heart disease.
Reviews indicate that patients with osteoporosis also suffered from extensive calcium plaque buildup, which impeded their blood flow in their arteries.
To test this, rats in one study were given a “calcification-inducing diet” and then were given either vitamin K and a blood thinner, a normal intake of vitamin K, or a high amount of vitamin K (K1 and K2).
Calcification in the arteries increased in all the groups except those taking high doses of K1 and K2. Those taking high doses of K1 and K2 decreased their arterial calcium content “by some 50%.”
Scientists believe that since MGP is dependent on vitamin K, it becomes a powerful inhibitor of calcification when given enough vitamin K to work with, which means that calcified arterial plaque can not only be prevented, it may be reversible.
The Rotterdam Heart Study of 4,800 participants makes note that vitamin K2 is more protective than K1 against coronary heart disease.
It even reveals that participants who consumed the greatest quantities of K2 in their diet had a 57% reduction in death from heart disease than people who consumed the least.
There are other studies that back up the efficacy of K2.
Data from over 10 years of following 16,057 female participants shows that the longer chain K2 vitamins (MK-7 through MK-9) prevent excessive calcium accumulation in the arteries the most.
And when mice were genetically bred to be deficient in a protein that uses vitamin K2, scientists noticed an excess of calcium deposits in the major arteries that was so bad the mice died within a few weeks of their birth.
These studies all point to one key fact: K2 has a significant and noticable effect on both bone and cardiovascular health.
According to one clinical trial, vitamin K2 increased survival times for patients with liver cancer. The researchers even suggested that K2 may be able to suppress the recurrence of liver cancer in patients so they are not prone to relapse.
A study published in the International Journal of Oncology explains that vitamin K2 also slowed the growth of lung cancer cells in patients so they had more time to treat their condition before it got worse.
And one observational review of 11,000 men found that while K1 had zero effect on prostate cancer, K2 was associated with a 63% lower risk of developing into advanced stages.
Now even though these studies offer exciting news, we still have to wait for additional clinical evidence to firmly advocate K2 for cancer treatment.
Where to Get Vitamin K2
Like I mentioned earlier, most of us consume very little K2 because it occurs in much smaller quantities in our diet. Even when we get vitamin K we’re only getting 10% of that in K2 form.
You’ll find vitamin K in dark green leafy veggies, herbs, those amazing cruciferous veggies, and soybeans.
K2 can be found naturally or as a result of bacterial fermentation.
Sources of vitamin K2 include:
- Egg yolks
- Grass-fed beef
- Organ meat
- Dairy products
- Natto (the richest source)
- Fermented cheese (Swiss Emmental and Norwegian Jarlsberg)
Keep in mind that bacteria in the colon produce approximately half of the vitamin K we need every day, so if you’re taking antibiotics, you’re killing off these necessary good bacteria, which may decrease your vitamin K intake.
The daily adequate intake of vitamin K for:
- Men 19 years and older: 120 mcg
- Women 19 years and older: 90 mcg
There’s no definite daily dose for vitamin K2 however. Supplements are usually sold in doses between 50 mcg–1,000 mcg.
If you believe you could be at risk for osteoporosis or heart disease, even just a low-dose supplement will help give you some of the benefits we discussed today.
Modest doses of K2 have the power to control calcium-regulating proteins in heart tissue to fight off heart disease. This also keeps calcium out of the arteries to prevent the dangerous formation of calcified plaque.
Remember, all of these conditions take years to develop, but the steps you take in your 20s–40s have a huge impact on where you’ll fall on the spectrum of severity.
Making sure to get proper nutrition early in life means you may not need to rely on expensive prescriptions later down the line.
Speak with your doctor if you want to start adding more vitamin K2 to your diet.
If you take blood thinners or warfarin such as Coumadin®, you’ll definitely need to get the green light from your doctor before you begin supplementing.