Vitamin K2, often cited for its potential benefits for bone and cardiovascular health, also raises questions about the possible dangers associated with its consumption.
Before addressing these concerns, it is essential to remember thatvitamin K2 , like all vitamins, plays a fundamental role in our body. In this article, we will examine all the potential risks associated with vitamin K2.
The role of vitamin K2
The different forms of vitamin K2
There are several forms of vitamin K2 , called menaquinones, which are designated by numbered subtypes, such as MK-4, MK-7, MK-8, etc. Of these subtypes, the most studied and used in dietary supplements are MK-4 and MK-7.
- MK-4: This form is found primarily in animal products such as liver, eggs, and meats. It is rapidly absorbed into the body, but has a relatively short half-life, meaning it does not stay in the body for long.
- MK-7: Derived primarily from fermented foods such as natto (a fermented soy product popular in Japan), MK-7 is particularly prized for its bioavailability and long half-life, allowing it to remain active in the body for longer. This form is often preferred in dietary supplements for its long-lasting effects on calcium metabolism.
The role of vitamin K2 in calcium metabolism
One of the most important roles of vitamin K2 is to regulate how calcium is used in the body. Calcium is an essential mineral for strong bones and teeth, but it must be properly distributed to prevent deposits in arteries and other soft tissues, which could lead to cardiovascular complications.
Vitamin K2 activates specific proteins that help direct calcium to bones and prevent it from building up in blood vessels and organs . For example:
- Osteocalcin: This is a protein produced by osteoblasts, the cells responsible for bone formation. Vitamin K2 activates osteocalcin, allowing calcium to properly attach to bones, contributing to their density and strength.
- Matrix Gla Protein (MGP): This protein is responsible for preventing calcium deposition in the arteries. Activated by vitamin K2, MGP plays a fundamental role in preventing arterial calcification.
The role of vitamin K2 in blood clotting
Like vitamin K1, vitamin K2 is involved in the blood clotting process. This process is essential to prevent bleeding in the event of an injury. Vitamin K2 helps activate certain clotting factors , which are proteins needed to form blood clots , thereby helping to seal vascular injuries.
However, it is important to note that vitamin K2, although involved in clotting, does not cause spontaneous blood clots to form. It only ensures the availability of clotting factors when needed, which is essential for the proper functioning of the hemostatic system.
Is Vitamin K2 Dangerous?
In general, vitamin K2 is considered safe when consumed as part of a balanced diet or in the form of dietary supplements at recommended doses.
No serious side effects have been associated with this vitamin, even at relatively high doses. However, specific precautions apply in certain contexts, particularly in people taking anticoagulant treatments.
Interactions with anticoagulants
One of the few contexts where vitamin K2 consumption may require increased vigilance is in individuals taking anticoagulant medications, such as vitamin K antagonists (VKAs). These medications work by inhibiting the action of vitamin K , which is essential for blood clotting. Therefore, excessive vitamin K2 intake could reduce the effectiveness of these treatments and increase the risk of blood clots.
That being said, it is essential to maintain a stable intake of vitamin K2 to avoid fluctuations that could interfere with the effectiveness of blood thinner treatment. Health professionals generally recommend that patients on blood thinners consult a doctor before taking vitamin K2 supplements.
Vitamin K2 toxicity and dosage
- One of the recurring questions is whether there is a maximum dose that should not be exceeded to avoid adverse effects. According to the European Food Safety Authority (EFSA), vitamin K, including K2, has no known toxicity, even at high doses. No upper safety limit has been set for vitamin K, indicating a high safety profile. Studies have shown that even doses of more than 10 mg per day have not caused harmful effects in healthy subjects.
H2 Precautions to take
Although vitamin K2 is widely considered safe, there are some precautions to be taken. Aside from potential interactions with blood thinners, it is important to choose quality sources of vitamin K2 and follow the dosages recommended by nutrition experts. Vitamin K2 is found primarily in animal and fermented foods, but it is also possible to consume it in the form of dietary supplements.
However, it is always advisable to consult a healthcare professional before incorporating a new supplement into your regimen, especially if you are taking medication or have any specific health conditions.
Vitamin K2, with its central role in calcium metabolism and blood clotting, is an essential nutrient for maintaining optimal balance in the body. The risks associated with its consumption are low, if not non-existent, for the majority of individuals.
However, it is essential to remain vigilant, particularly in the case of anticoagulant treatment, and to respect the recommended dosages to maximize the benefits of vitamin K2 while avoiding undesirable interactions.
Sources:
- European Food Safety Authority (EFSA). Dietary reference values for vitamin K .: https://www.efsa.europa.eu/en/press/news/170522-1#:~:text=10%20%C2%B5g%20for%20infants%20aged%207-11%20months.%2012,for%20adults%20including%20for%20pregnant%20and%20lactating%20women.
- French Food Safety Agency (AFSSA). Evaluation of vitamin and mineral content of fortified foods and food supplements. : https://www.anses.fr/fr/system/files/NUT2007sa0315x.pdf
- US Pharmacopeial Convention. Safety evaluation of menaquinone-7, a form of vitamin K .: https://pubmed.ncbi.nlm.nih.gov/38443482/
