Vitamin D plays an important role in the body's calcium metabolism. To prevent the risk of vitamin D deficiency, the sunshine vitamin is taken as a dietary supplement in the winter months. However, some sources claim that taking vitamin D is harmful if you have low vitamin K levels. For this reason one iscombined intake of the two vitaminsrecommended. But why should you always take vitamin D3 and K2 together? Does this recommendation always make sense? We'll explain it to you!
What are vitamins D and K?
Vitamin Dbecomesproduced by the skin, when exposed to sunlight, but is also found in fatty fish and fish oil. However, the amounts of vitamin D in food are not sufficient to cover the body's daily requirements. One of the most important functions of vitamin D is to promote calcium absorption and maintain adequate calcium levels in the blood. Vitamin D deficiency can lead to the development of osteoporosis.
Vitamin Kis found in leafy greens, fermented legumes and vegetables, as well as some fatty animal foods such as egg yolks, liver and cheese. It is necessary for blood clotting and promotes the storage of calcium in bones and teeth.
Vitamin D and K are bothfat-soluble Vitamine. This means that their absorption into the bloodstream is improved when taken with fat.
Vitamin D3 and K2 as a team
When it comes to calcium metabolism, vitamins D and K work in synergy. This means that they reinforce each other's effects.
The role of vitamin D
Vitamin D ensures the maintenance of adequate calcium levels in the blood. This happens in two ways: Vitamin D improves the absorption of calcium from food and prevents the absorption of calcium from the bones.
While calcium is best known for its role in bone health, it also has many other vital functions in the body. If you don't get enough calcium, your body will rely on the calcium reserves in your bones.
The role of vitamin K
As already mentioned, one of the main functions of vitamin D is to ensure adequate calcium levels in the blood. However, vitamin D does not affect where calcium ends up in your body. This is where vitamin K comes into play.
Vitamin K promotes the accumulation of calcium in the bones and teeth while preventing calcium from depositing in soft tissues such as the kidneys and blood vessels. Calcification of blood vessels is associated with the development of chronic diseases such as heart and kidney disease.
To date, there have been few controlled human studies examining the effects of vitamin K supplements on blood vessel calcification, but further studies are underway.
Is taking vitamin D3 without vitamin K2 harmful?
Some experts claim that high vitamin D intake could promote blood vessel calcification and heart disease in people with low vitamin K levels. There are several pieces of evidence that partially support these claims:
- A vitamin D overdose causesHypercalcemia– a condition characterized by excessively high levels of calcium in the blood.
- Hypercalcemia leads to aCalcification of blood vessels(arteriosclerosis), which in turn is a leading cause of heart disease.
- Observational studies have onelow vitamin K levelsassociated with an increased risk of blood vessel calcification.
- Vitamin K supplements can slow the progression of arteriosclerosis. A controlled study in older people showed that taking 500 mcg of vitamin K1 daily for three years slowed arteriosclerosis by 6 percent.
Simply explainedAn excess of vitamin D can cause calcification of blood vessels, while vitamin K can help prevent this.
Even if this evidence seems sufficient, there are still some pieces of the puzzle missing. While extremely high doses of vitamin D can lead to dangerously high calcium levels and blood vessel calcification, there is still no clear evidence that moderate amounts of vitamin D without adequate vitamin K intake are harmful in the long term. Further research is needed before the validity of this theory can be fully confirmed.
How do you get enough vitamin K?
There are two families of vitamin K, K1 and K2.Vitamin K1, also called phyloquinone, is found primarily in leafy vegetables such as kale and spinach.
The best known compounds of vitamin K2 areMenaquinone-4 (MK-4) and Menaquinone-7 (MK-7). MK-4 is found in animal products such as liver, egg yolks and cheese.MK-7is formed in fermented foods such as miso, natto and sauerkraut. It is also produced by our intestinal bacteria.
How much vitamin K per day?The current nutritional recommendations do not differentiate between vitamin K1 and K2. For people aged 19 and over, the requirement value is 90 µg for women and 120 µg for men.
Here we have listed the foods that are considered the best sources of vitamin K1 and K2. Including some of these foods in your daily diet can help you meet your vitamin K needs.
Vitamin K1 (μg pro 100 g)
Parsley – 1640 mcg
Kale – 704.8 mcg
Spinach – 482.9 μg
Brussels sprouts – 140 μg
Kohl – 109 μg
Lettuce – 102 μg
Broccoli – 141 μg
Vitamin K2 (μg pro 100 g)
Fermented Soybeans (Natto) – 775 μg
Goose liver – 369 μg
Beef liver – 106 μg
Pork chops – 69 μg
Because vitamin K is fat-soluble, taking it with fat can improve absorption. For example, you can add some oil to your salad or take your supplements with a fatty meal.
Do not take very high doses of vitamin K supplements before speaking to your doctor because interactions with certain medications may occur.
Conclusion
Scientists are still researching the functions of vitamins D and K. You don't fully understand how they work together yet, but little by little new pieces of the puzzle are being added. It's clear that vitamin K is beneficial for the heart and bones, but it's unclear whether high-dose vitamin D supplements are harmful if you're deficient in vitamin K. However, you should make sure that you get sufficient amounts of vitamin D and K in your diet. Both are important.
