I was listening to a great webinar the other day hosted by Dr. Lani Simpson and featuring Dr. Kate Rheaume-Bleue, author of the book The Calcium Paradox. This is one of the first books to shed light on the importance of K2 supplementation for bone and cardiovascular health. This talk reminded me just how very important Vitamin K2 is for the health of our bones and our body, so I decided to remind you all as well!
Vitamin K2, a little known nutrient just until a few years ago, has emerged as having a critical role in how the body uses calcium. It is tasked in moving and keeping calcium in the bones and out of places where it shouldn’t be, such as arteries, joints, the kidney and bladder where it can contributed to calcification, heel spurs, bone spurs and kidney and bladder stones.
Vitamin K2 is very different than vitamin K or K1. Vitamin K1, has been long recognized as being important for blood clotting. Because of this critical role, it is rare that we become deficient in vitamin K1. Not only do we get plenty of K1 through our diet, but the body continually recycles K1 to ensure it is ever present. However, it is quite common to become deficient in K2. It is more difficult to get K2 in our modern day diet and K2 is not recycled like K1. According to Dr. Rheaume-Bleue, people can develop a deficiency of K2 in as few as 7 days if not adequately supplied by the diet.
The reason why vitamin K2 is so important is that it activates two key proteins in the body:
- Osteocalcin: once activated, it carries calcium and minerals into bones and teeth.
- Matrix-GLA: activation of the matrix-GLA protein (MGP) inhibits tissue calcification. This protein is activated only in the presence of Vitamin K2.
Through activation of these 2 proteins, vitamin K2 can keep our bones strong and keep calcium from mineralizing in soft tissues of the body.
Role of Vitamin K2 for the Bones and the Body
- Bone Health: Inhibits osteoclast (cells that break down bone) and activates osteocalcin, which helps take calcium from the blood circulation and bind it to the bone matrix.
- Cardiovascular Health: Inhibits the deposit of calcium on the blood vessel walls which can lead to arterial calcification and arterial stiffening.
- Prostate Cancer: A study published by the European Prospective Investigation into Cancer and Nutrition revealed that increased intake of vitamin K2 may reduce the risk of prostate cancer by 35%.
- Improves Insulin Sensitivity: May help to ward off insulin resistance that can lead to diseases such as diabetes, heart disease and cancer.
- Dental Health: Saliva is rich in vitamin K2 where is aids in reducing cavity-causing bacteria and mineralization of the teeth.
- Kidney/bladder Stones: By activating the protein that inhibits mineralization, it may help to prevent stone formation.
- Varicose Veins: Prevents accumulation of calcium deposits in veins which can contribute to varicose veins.
- Wrinkles: Activates MPG in the skin, preventing calcification of elastin that can lead to wrinkles.
With all these fabulous benefits, you might be thinking “I should included more foods rich in vitamin K2 into my diet.” However, this is harder than you think. Vitamin K2 comes from fermented foods and grass fed, but not grain fed, animals. In animals, vitamin K1 obtained from munching on green grass, can be converted into K2. Animals fed a diet of grain will lack K1 and therefore K2. Humans can also convert K1 from leafy greens to K2, but at a very low rate. Our gut flora can make K2 as well, but not enough to make a significant contribution to our health.
The best sources of K2 are natto and goose liver, both which may be hard to stomach. Natto is a fermented soy food frequently eaten in Asian countries. You can also get K2 from grass fed animal products like cheese, eggs, and butter and most recently discovered from pork. Cheeses richest in K2 are Brie, Gouda, Jarlsberg and some Blue cheeses. However, you will have to eat a whole lot of cheese, eggs and butter to reach your daily requirement of K2.
So supplementing with K2 may be your best choice. However, there have been different thoughts about what type of K2 you should supplement with. There are 2 forms of vitamin K2 that are typically found in supplements: MK-4 and MK-7. The M in MK stands for menaquinone and the K stands for vitamin K. The numbers have to do with the length of the carbon tail on the chemical chain. The higher the number, the longer the chain and the longer it stays in the body. The initial studies on K2 and bone health used MK-4 and showed that when used in high doses (45 mg/day), MK-4 was positively associated with reduced risk of fractures. However, recently, more research suggests MK-7, which can be taken at lower doses, increases bone mineral density as well. The benefits of MK-7 is that it stays in the blood stream longer and you need a lower dose for efficacy.
According to Dr. Kate Rheaume-Bleue, either form is beneficial, but if your supplement contains MK-4 you will have to take a higher dose and more frequently. Much of the MK-7 used in supplements is soy-based, so if you have a soy allergy or otherwise want to avoid soy, so will need to find an alternative.
How much vitamin K2 do you need?
Maintain General Health – 100-120 mcg, at least a portion of that should be MK-4, but it’s not clear how much!
Increase bone density – 180 mcg of MK-7 is best
Reduce arterial calcium – 400 mcg
So as you can see, we are in our infancy when it comes to understanding how much and what kind of K2 is needed. K2 is actually produced in several different lengths, MK-4 through MK-11, and only MK-4 and MK-7 have been researched….so future research on the other types could prove beneficial as well.
For now, If your not eating a daily helping of Natto or goose liver, be sure you are taking a supplement that provides K2, not just K1.