Vitamin D3 and K2: Everything you need to know about the vitamin combination
One of the most sought-after products in the field of nutritional supplements is the combination of vitamins D3 and K2 - and for good reason. Both vitamins act as partners in important metabolic processes. Together they help maintain normal bones and teeth. We have compiled for you here how this works and what other secrets are hidden behind these two vitamins.
Sunlight activates the production of vitamin D in the body.
What exactly is vitamin D?
Most of us know vitamin D as the sunshine vitamin. This is because we do not get most of what we need from food, but from our body's own production in our skin, which is activated by sunlight. More precisely: through UV-B radiation within sunlight. At the same time, we also get vitamin D from food, for example from fatty fish such as salmon or mackerel. But vitamin D is also found in plant-based foods, for example in avocados or mushrooms.
Why do we need vitamin D?
Vitamin D is involved in numerous processes in the human body: for example, it contributes to the normal function of the immune system and it has a function in cell division. But it is particularly important in relation to the mineral calcium: for example, vitamin D contributes to a normal calcium level in the blood. It is important for maintaining normal muscle function and, above all, for maintaining normal bones and teeth. A sufficient vitamin D level can also reduce the risk of falls and thus minimize a risk factor for bone fractures.
Is vitamin D deficiency a problem?
An evaluation of representative studies by the Robert Koch Institute (RKI) from 2019 shows that only 44% of adult subjects in Germany have sufficient vitamin D levels (serum level ≥ 50 nmol/l). More than 15% of subjects have a vitamin D level below 30 nmol/l - and thus an inadequate vitamin D supply with an increased risk of diseases such as osteomalacia and osteoporosis. This becomes particularly serious when you look at the data from older population groups, especially women between 65 and 79 years of age. Over 90% of subjects in this group have a suboptimal vitamin D status. This often has noticeable consequences for those affected: tiredness, susceptibility to infection or fatigue are the typical symptoms. Mood swings are also associated with a vitamin D deficiency. Vitamin D deficiency is also considered a risk factor for various diseases such as rickets or osteoporosis.
What is vitamin D in supplements made from?
Vitamin D is normally produced by UV irradiation of lanolin, a fat extracted from the wool of living sheep. However, the animals are not sheared to produce wool fat, but to extract the wool - the wool fat is thus a by-product, so to speak, and only very small amounts are needed to produce vitamin D. The sheep then live happily, but lanolin is nevertheless strictly speaking not a vegan product, but a vegetarian one. There are now also vegan production options in which certain lichens (i.e. fungi) are treated with UV radiation. The vitamin D2 contained in them is extracted, which is then converted into vitamin D3 in a biochemical process. The end product is chemically absolutely identical in both cases, so even precise analytical procedures cannot determine any difference. The effect on the body is also identical, because in both cases it is exactly the same substance. The only question is whether a strictly vegan product is more important to you than the traditional and tried and tested process. Since animal welfare is guaranteed in our production and the actual product is absolutely identical, we have opted for the traditional production variant for our Vitamin D3.
Which people should pay particular attention to their vitamin D levels?
The less time you spend in the sun, the more likely it is that you will develop a vitamin D deficiency. Risk factors are therefore all the things that keep you away from the sun: working in an enclosed space, not doing much outdoor exercise or excessive use of sunscreen, to name just a few examples. In seniors over the age of 65, the body's own vitamin D production also decreases. In addition, other factors such as chronic underlying diseases or taking medication can increase the risk of vitamin D deficiency.
What is Vitamin K?
Vitamin K includes a whole group of vitamins with a similar basic structure but partly different physiological function for the human body. Like A, D and E, they are fat-soluble vitamins. Vitamins K1 and K2 are important for our metabolism. Vitamin K1, also known as phylloquinone, plays an important role in photosynthesis, i.e. the production of energy in plants. This takes place in the chloroplasts, which are colored green by chlorophyll. Green plants such as spinach, broccoli or kale are therefore very good sources of vitamin K1. Vitamin K2 or menaquinone is produced in the healthy body by bacteria in the intestinal microbiome . According to estimates, 10 to 50 percent of the daily requirement is covered in this way, depending on how well the intestinal flora is intact. Other good sources of K2 are meat, eggs and dairy products, as well as fermented foods such as sauerkraut, cheese or the Japanese specialty natto.
A normal meal contains enough fat to absorb vitamin supplements.
Why do we need vitamin K?
As early as 1929, the Danish researcher Carl Peter Henrik Dam suspected that there must be a substance that has an influence on the blood's ability to clot. In the years that followed, various experiments were carried out to identify the group of substances and grouped together under the name vitamin K. The K vitamins therefore play a role in the synthesis of proteins that are important for blood clotting. We now also know that vitamin K plays a role in bone formation. K2 in particular acts as a co-factor in the activation of the proteins osteocalcin and MGP (matrix GLA protein), which are important for calcium metabolism. Vitamin K - like vitamin D - therefore contributes to the maintenance of normal bones.
What does MK-7 all-trans mean?
Vitamin K2, also known as menaquinone or MK for short, comes in different forms, the so-called menaquinones. These consist of two parts. Firstly, the so-called naphthoquinone ring. This is crucial for the physiological function and is also a component of vitamin K1. The second part is a side chain of varying lengths, which is made up of a certain number of identical building blocks. In MK-7, this chain consists of seven building blocks. Variations from MK-4 to MK-10 are known in food. The position of certain double bonds can also change the geometric structure of the side chains. All-trans means that all double bonds are on the same side. This creates a relatively straight chain. If a bond were on the cis side, this would create a different geometric shape. The chain would essentially form a kink at this point. Cis variants are biologically inactive according to the current state of research. While the naphthoquinone ring determines the function of the menaquinones, the length and shape of the side chain determine the bioavailability. According to current knowledge, the variant MK-7 all-trans achieves the best bioavailability.
What is vitamin K made from?
The Japanese specialty Natto is famous for being the food with the highest vitamin K2 content. It is made from soybeans that have been boiled and then fermented by adding certain bacteria. The fermentation gives the soybeans a slimy coating that also forms sticky threads. For Western gourmets, this specialty takes some getting used to. However, since the menaquinone it contains is already predominantly in the MK-7 all-trans form, Natto is the perfect raw material for extracting natural vitamin K2. With modern extraction processes, 96 to 98 percent pure MK-7 all-trans can be extracted from it. If a preparation is declared to be 100 percent MK-7 all-trans, it is a synthetic product made from geraniol and citronella. Even if the synthetic products can be marketed as 100 percent pure, the processes used actually only achieve a maximum of 99 percent purity.
Why is vitamin D3 combined with vitamin K2?
Vitamin D3 and vitamin K2 work together in some metabolic processes. While vitamin D3 increases the intestine's ability to absorb calcium and thus ensures a normal calcium level in the blood, vitamin K2 is needed to make calcium available to maintain normal bones. Taking vitamin D without substituting vitamin K2 can even lead to a K2 deficiency under certain circumstances.
In what dosage are vitamin D3 and K2 permissible and useful?
The German Nutrition Society recommends a daily intake of 800 IU (20 µg) for adults with low levels of vitamin D production. However, this dose is still a long way from the tolerable upper intake level set by the European Food Safety Authority (EFSA): this is 4000 IU (100 µg) per day for adults, pregnant and breastfeeding women and children aged 11 and over, and 2000 IU (50 µg) per day for children up to 10 years. For vitamin K, the German Nutrition Society recommends a daily intake of 60 µg for women and 70 to 80 µg for men, although here too the upper limit is higher and depends on the simultaneous intake of vitamin D. If you are taking anticoagulants, for example to prevent thrombosis after surgery, you should definitely discuss taking vitamin K2 with your doctor beforehand, as it can be antagonistic to some anticoagulants. Overall, the intake of high-dose vitamin D3-K2 products should be discussed with a doctor to avoid overdose.
How should vitamin D3 and K2 supplements be taken?
Vitamin D3 and K2 are fat-soluble vitamins. They are treated by the body like other lipids and are only absorbed in the intestine. To increase the bioavailability of fat-soluble vitamins, they should be taken with a little oil. Preparations in tablet form are ideally taken directly with meals. The fats they contain are completely sufficient for the absorption of the vitamins.
