Vitamin K2: Side effects and safety

Vitamin K2: Side effects and safety

Taking vitamin K2 supplements can be a great way of ensuring our bodies are consuming enough of this nutrient to stay healthy. With vitamin K2’s ability to promote stronger bones and reduce the risk of heart disease, who wouldn’t be willing to try it? But many people worry about the safety of taking a dietary supplement. So it begs the question - exactly how safe are vitamin K2 supplements?

Vitamin K2 supplements are considered safe for the average person to take. They generally do not result in any adverse side effects, and the side effects that can occur are typically mild.

This article will clear up any questions or concerns you may have regarding the side effects and safety of vitamin K2 supplements. For a breakdown of who can add K2 into their diet and the best way to do so, we’ve got all the information. 

How safe are vitamin K2 supplements?

Vitamin K2 is a fat-soluble vitamin rarely found in the western diet - and because this vitamin has flown under the radar for so long, we may worry that not enough research has been done to ensure that it’s safe.

But this isn't the case - studies support the safety of vitamin K2 supplementation for human consumption at typical doses of vitamin K.

One study even tested whether or not vitamin K2 negatively alters our hemostatic balance, which refers to the equilibrium our vascular system needs for proper blood coagulation. 

They found that taking vitamin K2 supplements does not interfere with hemostatic balance, providing further evidence that this supplement is safe for us to handle. Vitamin K2 removes excess calcium from our blood vessels, helping to lower our risk of heart disease.

Studies also found that vitamin K2 supplements positively affect our bone mineral density, proving that these dietary supplements are safe but are very beneficial to our health.

Side effects of vitamin K2

While vitamin K2 supplements are generally considered safe, we still need to know about the possible mild side effects of taking them. These include:

  • Upset stomach 
  • Diarrhea
  • Dizziness
  • Shortness of breath

It’s important to note that these side effects are rare, but they are associated with the use of vitamin K in general. There are no specific side effects associated exclusively with vitamin K2.

Who should avoid vitamin K2 supplements?

A few sensitive groups may need to avoid vitamin k supplements. This includes pregnant or breastfeeding women and anyone taking the following medications:

  • Blood thinners
  • Phenytoin
  • Certain antibiotics
  • Orlistat
  • Bile acid sequestrants

Because these medications do not interact well with vitamin K2 supplements, we suggest that anyone who is taking them consult their doctor before increasing their vitamin K2 intake.

Do we need vitamin K2 supplements?

Many people prioritize getting their vitamins from food sources rather than supplements. If you’re one of these people, you may be wondering - do I need to take a vitamin K2 supplement to consume this nutrient?

Yes, the answer is most likely - vitamin K2 is found mainly in fermented foods like natto beans. Because food sources high in vitamin K2 are rare in the North American diet, the average person cannot get the recommended amount simply from their food.

The recommended amount of vitamin K2 per day

So exactly how much vitamin K2 do we need to consume daily to experience its benefits and avoid a vitamin K deficiency?

While there is not yet a recommended intake specifically for vitamin K2, studies suggest that 10-45 micrograms is a safe amount for us to take to experience the effects of this vitamin.

Because 90% of the vitamin K we receive from our diet is vitamin K1, we need vitamin K2 supplements to help us ensure we’re doing the most for our bones and heart health.

How to find the best vitamin K2 supplement for you

So you’re ready to take the next step in increasing your vitamin K2 intake - how do we know which supplements will work for us?

It’s important to make sure you’re buying vitamin K2 supplements from a trustworthy source. You should check the label when browsing supplement bottles to ensure they contain vitamin K2, sometimes listed as Menaquinone-7. 

Luckily, FuelOrganics offers a high-quality vegan K2 supplement for those looking to increase their intake of vitamin K2 and benefit from a healthier heart and bones.

Read more about Vitamin K2 During Pregnancy: Everything you need to know

Final thoughts

Vitamin K2 benefits our body in many ways, particularly when it comes to heart and bone health. Because the average western diet severely lacks this fat soluble vitamin, we need to find alternative methods to safely incorporate it into our system.

Luckily for us, vitamin K2 supplements have been studied specifically for their safety and are effective in giving us the vitamin K2 our bodies need.

So if you’ve been on the fence about adding this vitamin into your diet, this may be the push you need to finally experience all that vitamin K2 has to offer.

Trusted Sources

  1. Pucaj, K., Rasmussen, H., Møller, M., & Preston, T. (2011). Safety and toxicological evaluation of a synthetic vitamin K2, menaquinone-7. Toxicology mechanisms and methods, 21(7), 520–532.
  2. Ren, Ruijun MDa; Liu, Jia MDb; Cheng, Guo MDb; Tan, Jing MD, PhDb,∗ Vitamin K2 (Menaquinone-7) supplementation does not affect vitamin K-dependent coagulation factors activity in healthy individuals, Medicine: June 11, 2021 - Volume 100 - Issue 23 - p e26221 doi: 10.1097/MD.0000000000026221
  3. Zhang Y, Liu Z, Duan L, Ji Y, Yang S, Zhang Y, Li H, Wang Y, Wang P, Chen J, Li Y. Effect of Low-Dose Vitamin K2 Supplementation on Bone Mineral Density in Middle-Aged and Elderly Chinese: A Randomized Controlled Study. Calcif Tissue Int. 2020 May;106(5):476-485. doi: 10.1007/s00223-020-00669-4. Epub 2020 Feb 14. PMID: 32060566.
  4. Top foods high in vitamin K2 (2020). Retrieved from


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