What is Vitamin K?
Vitamin K is a group of fat-soluble vitamins that play an important role in blood clotting, bone metabolism, and the regulation of calcium levels in the body. There are two naturally occurring forms of Vitamin K: K1 (phylloquinone) and K2 (menaquinone). K1 is most commonly found in green leafy vegetables, while K2 is primarily found in fermented foods and certain animal products.
What Symptoms & Side Effects Are Caused by Vitamin K Deficiency?
The symptoms and side effects of Vitamin K deficiency are mainly related to its role in blood clotting and bone metabolism. Prolonged Vitamin K deficiency can increase the risk of bleeding and osteoporosis, which in turn can cause other health problems.
Is Vitamin K Found in Food?
Yes, Vitamin K is found in several foods. Vitamin K1 is abundant in green leafy vegetables such as spinach, kale, broccoli, and avocado. Vitamin K2 is found in fermented foods like natto, sauerkraut, and certain cheeses, as well as in animal products like liver, meat, and egg yolks.
Can You Overdose on Vitamin K?
It is unlikely to overdose on Vitamin K from food sources, as the body regulates the absorption of the vitamin. However, overdosing on Vitamin K from supplements can lead to side effects, such as an increased risk of blood clots and liver damage, particularly if you are also taking blood-thinning medications. It is important to follow recommended doses and consult a doctor or pharmacist when using supplements.
How Much Vitamin K Do You Need?
The recommended daily intake (RDI) for Vitamin K varies depending on age, gender, and lifestyle. Generally, the following intake is recommended for adults:
- Men: 120 micrograms (µg) per day
- Women: 90 micrograms (µg) per day
- Pregnant and breastfeeding women may need higher doses, so it is important to consult a doctor or midwife to ensure sufficient Vitamin K intake during these periods.
Vitamin K and Vitamin D
Vitamin K and Vitamin D work together to promote a variety of health benefits in the body, making it important to maintain a balance between these two nutrients. If you are taking Vitamin D supplements, it is important to also consider your Vitamin K intake, as these vitamins work together in the following ways:
- Bone Health: Both Vitamin D and Vitamin K contribute to maintaining strong and healthy bones. Vitamin D helps increase calcium absorption in the intestines, while Vitamin K activates proteins that help bind calcium to the bone structure. By working together, these two nutrients reduce the risk of osteoporosis and fractures.
- Calcium Regulation: Vitamin D promotes calcium absorption in the body, which is important for bone health, but can also lead to calcium being stored in blood vessels and soft tissues, potentially causing health problems. Vitamin K helps prevent these issues by directing calcium to the bones and away from blood vessels and other soft tissues.
- Cardiovascular Health: Vitamin K is involved in preventing the calcification of arteries, a process that can lead to atherosclerosis (hardening of the arteries). Vitamin D, on the other hand, affects blood pressure and inflammation levels in the body. Together, they help maintain healthy cardiovascular function.
Do not take high doses of Vitamin D (5000 IU) without also taking Vitamin K. For this reason, Vitamin D from MegaFood and Innate Response also contains both Vitamin K1 and Vitamin K2.
Sources & References
National Food Agency: https://www.livsmedelsverket.se/livsmedel-och-innehall/naringsamne/vitaminer-och-antioxidanter/k-vitamin
Mladěnka P, Macáková K, Kujovská Krčmová L, Javorská L, Mrštná K, Carazo A, Protti M, Remião F, Nováková L; OEMONOM researchers and collaborators. Nutr Rev. 2022 PMCID: PMC8907489.
