Vitamin K is an important micro-nutrient that has a vital role as a co-factor for the γ-carboxylation of glutamic acid residues in a number of proteins. It’s very important for the proper function of these proteins, and for the proper regulation of bone and vascular calcium homeostasis [1]. Many studies proved that, and that’s why Vitamin K2 supplements are pretty popular nowadays. In this article I will also tell you about my experience with Vitamin K2 supplements – and why you should avoid them.
Most Vitamin K supplements provide it in MK-4 or MK-7 form, but there are many additional forms – and they all share a common ring structure : 2-methyl-naphthoquinone. It’s also known as menadione. They all differ in the composition of the poly-isoprenoid side chain attached at the 3-position.
Vitamin K Forms
Vitamin K1 is synthesized by various green plants. It has a side chain of 4 isoprenoid residues (of which the first one is unsaturated). You can get Vitamin K1 in your diet by eating green and/or leafy vegetables (for example – broccoli and spinach). This is doable on the keto diet, but for carnivores (and nowadays the carnivore diet is almost as popular as keto) – not so much. That’s why many people on the carnivore diet use Vitamin K supplements (which is a big mistake in my opinion).
Vitamin K2 forms differ from each other in the length of their side chains at the 3-position (MK-1 ,MK-2, MK-3, MK-4, MK-5, MK-6, MK-7, MK-8, MK-9, MK-10 : the number after MK- stands for the number of isoprenoid residues in the side chain). The most abundant source for Vitamin K2 is fermented dairy products – such as cheese [2]. It’s important to note that different cheeses differ in their Vitamin K2 content and distribution (for example – some cheeses contain MK-10 almost solely, while others contain all MK forms in good amounts).
Vitamin K2 Supplements – Avoid Them
In the past decade, many new studies have shown the importance and health benefits of the K2 vitamins [3,4]. This increased the popularity of Vitamin K supplements. While many people report great results with them – others report serious side effects. One of them is heart palpitations.
After a few weeks of taking 100mcg of a Vitamin K supplemen (K2 MK-7), I started having heart palpitations as well. There are hundreds of people telling the same story online. I stopped taking MK-7 and the symptoms disappeared within a week. The half-life of Vitamin K2 MK-7 is about 3 days. This means it accumulates in your body – you may only take 100mcg a day – but it adds up. That’s why some people prefer taking MK-4 which has a half life of just a few hours. In my opinion – these supplements are not worth the risk. And, in most cases they provide Vitamin K2 in only one or two forms (most popularly MK-4 and MK-7). Why not eat real food, and enjoy Vitamin K2 in all its forms?
One can easily “naturally supplement” with Vitamin K2 by eating cheese regularly. Gouda, Milner, Slankie, Camembert, Stilton, Münster and many other cheeses – are a great option, and are very high in all forms of Vitamin K2. They are not cheap (and in many cases cost more than premium cuts of beef pound-to-pound), but you don’t have to eat a pound a day. Try eating 3.5oz (100g) a day – that’s why I do, and the results are great.
You can also prepare cheese at home (soon we will post keto cheese recipes on KetoAndEat), but generally speaking – fermented and aged cheeses are richer in VItamin K2. These cheeses are also very low in carbs (many of them contain 0 carbs), so they are perfect for keto. People on the carnivore diet should also consider eating cheese regularly – it’s from the animal kingdom! You don’t have to buy super expensive cheese – there are plenty of high quality cheeses you can buy at your local supermarket. Many of them also don’t contain any additives.
I hope you will find this article useful. Make sure to check out great keto recipes on our website – KetoAndEat. We post new recipes on a weekly basis. Most of them are super easy to make, and of course – perfect for people on the keto diet.
In my experience MK4 and MK7 are totally different. Mk7 also gave me the same heart palpitations you mentioned.
MK4 on the other hand felt amazing. First few times I took it, I felt really noticeably relaxed, and it had this obvious mental effect. I’ve given the same supplement to 4 other people and they all experienced exactly the same mental effect. Within two weeks I had a noticeably higher libido and more energy. I looked it up later and apparently MK4 is stored in the brain and sex organs. It doubles the testosterone of rats.
Nowadays it no longer has any significant effect when I take it, and I just take enough for maintenance. I assume its because I was deficient and now I’ve filled up the Mk4 stores in my tissues and organs.
For some context, I was already eating lots of grass fed beef and liver for over a year as well as regularly having all kinds of cheeses before I supplemented with k2.