Dr. Truls Marius Aarra
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Anyone who regularly takes vitamin D as a dietary supplement also needs to take vitamin K2. This important vitamin is responsible for depositing calcium at the right places in the body - i.e. in the bones and teeth. It also prevents calcification, the accumulation of calcium in places where it is not required - i.e. in the arteries and other soft tissue of the body.
Taking vitamin D stimulates the body to produce more of the vitamin K2-dependent proteins that transport calcium. These proteins have many health benefits, but cannot be activated if insufficient vitamin K2 is available, so anyone who is taking vitamin D needs more vitamin K2. Vitamin D and K2 work together to strengthen bones and promote the health of the heart and arteries.
Vitamin D3 helps your body absorb calcium from the diet. But without enough vitamin K2, that calcium may not be directed where it’s needed such as your bones and teeth and can instead end up in soft tissues like arteries, potentially leading to calcification and arteriosclerosis.
Vitamin K2 activates specific proteins such as osteocalcin and matrix Gla-protein (MGP) that:
In short: Vitamin D3 increases calcium availability, while vitamin K2 ensures it’s used properly.
Taking vitamin D increases the body’s production of vitamin K2-dependent proteins. But without enough K2, these proteins remain inactive, and calcium can go to the wrong places. Together, D3 and K2:
As the intestines only produce small quantities of vitamin K, we have to provide a supply from foods or supplements that are rich in vitamin K. There is clear evidence that vitamin K intake is too low in Western civilisation.
People over the age of 50 are particularly vulnerable to cardiovascular disease and osteoporosis, but it is precisely at this age that the diet often contains even less vitamin K and the skin's exposure to sunlight is also severely limited, thus leading to deficiencies in vitamin K and vitamin D.
Professor Vermeer of the University of Maastricht thus recommends that people aged over 50 take a dosage of 100 to 200mcg vitamin K2 per day. The higher dosage of 200mcg is especially recommended for people who have a history of cardiovascular disease or osteoporosis in their families.
People who have early indications of cardiovascular disease or osteoporosis can also take the higher dose to ensure that all the body's matrix Gla proteins (MGPs) are activated.
45mcg of vitamin K2 a day is generally enough for healthy people under the age of 50, but this recommendation only applies if there is no additional vitamin D3 intake from dietary supplements.
Anyone who wants to ensure an optimal supply and guarantee that all vitamin K2-dependent proteins are activated in the body should take at least 100mcg.
This recommended vitamin K2 intake applies regardless of whether or not it is taken together with vitamin D3, so even if you aren't taking a vitamin D supplement you should still maintain the above dosage of vitamin K2.
Note: If you are taking medication (anticoagulants) to prevent blood clots, please consult your doctor before taking vitamin K2.
Since our bodies have an absolute necessity for vitamin K in order to keep our bones healthy and our arteries clean, we recommend not taking anticoagulant medication that acts on the basis of vitamin K inhibition - please ask your doctor to prescribe another anticoagulant that works independently of vitamin K.
If this is not possible, you can still take 45mcg of vitamin K2 every day. Studies show that this dosage does not influence the effect of blood-thinning medication and creates no risk that blood clots will form.
The right vitamin K2 dosage depends on your age, health status, and whether you're taking vitamin D3:
Vitamin K2 Dosage | Who It’s For |
---|---|
45 mcg/day | - People on vitamin K antagonist anticoagulants - Healthy individuals under 50 not taking D3 supplements |
100 mcg/day | - Healthy individuals - Anyone taking up to 2,500 IU of vitamin D3/day |
200 mcg/day | - People with a family history or symptoms of cardiovascular disease or osteoporosis - Anyone taking more than 2,500 IU of vitamin D3/day |
Important: If you’re taking anticoagulants, consult your doctor before using vitamin K2 supplements.
Your body makes vitamin D3 through sun exposure, but most people don’t get enough year-round. Aim for a blood level of 50–80 ng/ml of 25(OH)D.
Vitamin D3 Dosage | When to Use It |
---|---|
2,500–5,000 IU/day | For most people to maintain optimal levels |
>5,000 IU/day | Only with regular blood testing every 3 months |
We recommend taking vitamin K2 consistently throughout the year, daily and at the best dosage for you (as described above). Adjust the dosage of vitamin D3 to suit your lifestyle, or - even better - to suit the level of vitamin D3 25(OH)D in your blood.
If you sunbathe for a sufficient time more than twice a week in summer, you probably won't need any extra vitamin D3 at this time of year. For the rest of the year, experts recommend adjusting vitamin D intake to suit your lifestyle and age, so that your 25(OH)D level remains in the optimal range of 50 to 80 ng/ml.
Experience has shown that for most people, depending on the time of year, a daily dosage of between 2500 and 5000 IU of vitamin D3 is the best way to maintain a healthy level of 50-60 ng/ml of 25(OH)D in the blood.
Vitamin D3 and vitamin K2 work together directly, but the dosages of these two vitamins are independent of each other, which means that no matter how much vitamin D3 you take, the optimal dosage in order to benefit from the full effect of vitamin K2 always remains the same - between 100 and 200 mcg per day (see above for more information).
Note: If you have a regular daily intake of more than 5000 IU, we recommend that you have the level of 25(OH)D in your blood tested every 3 months. This test is especially useful when you begin taking vitamin D3, to find out how much vitamin D3 you need to take every day to achieve an optimal level.
Vitamin K2 has been the subject of many scientific studies for several decades, but it was only the impressive studies of vitamin K2 conducted at the University of Maastricht that drew such attention to its enormous importance to our health.
Vitamin K2 controls the way that the mineral calcium is stored and used in the body. This is performed by the utilisation of vitamin K2-dependent Gla proteins, which can only be activated by vitamin K2.
Although vitamin D3 causes the formation of osteocalcin, only vitamin K2 can activate osteocalcin, the protein that stores calcium in the bones.
Vitamin K2 also activates matrix Gla protein (MGP), which is responsible for the regulation of calcium in the arterial walls. MGP is the most effective inhibitor of arterosclerosis and can only be activated by vitamin K2. A lack of vitamin K2 therefore leads inevitably to hardening of the arteries.
Without activated Gla proteins, calcium migrates uncontrollably from the bones into the arteries, where it promotes arterosclerosis. In the absence of vitamin K2, calcium circulating in the body that has been absorbed from food by vitamin D is also deposited in the soft tissues of the body and in the arteries, leading to arterosclerosis.
Vitamin D3 should therefore always be taken in combination with vitamin K2. These two vitamins work together synergistically and ensure that calcium obtained from food is deposited in the bones and not in the arteries.
There is no “best” product for everyone. It is important that D3 comes from a high-quality source, preferably cholecalciferol. K2 should be in the form of MK-7 all-trans because it is the most stable. Drops are practical because you can dose them precisely, while capsules are more convenient for on the go. Also, make sure that the supplement is dissolved in oil, as D3 is fat-soluble.
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