Vitamin K – King of the Jungle

by on April 25, 2017

We all know the importance of our fat soluble vitamins A, E, D and K. The first 3 have been covered over and over again in the fitness industry due to their excellent anti-inflammatory and antioxidant effects. Because of the high cost of conducting Vitamin K studies, the lucky last of the fat soluble vitamins has often been overlooked as the powerhouse of the Vitamin family. As you’ll soon find out, it might be our secret to not only living longer, but getting stronger, jacked and ripped!

The Secret Powers of K

How many of you reading this want to increased performance in the gym? How about the guys out there wanting an increase in testosterone and fertility? What about increasing insulin production and sensitivity? I don’t know about you, but I definitely do! Who wouldn’t want a bigger, stronger, leaner body?

Well ladies and gentlemen, put your mind at ease because these benefits and more can all be attributed to Vitamin K[1,2,3]. We all know that Vitamin K helps deposit calcium in all the right places like bones and teeth, but it’s benefits for athletes as a supplement on it’s own are often overlooked.

Is all K created Equal?

There are two types of Vitamin K – K1 and K2. K2 is even further split up into subgroups all denoted by MK(standing for Menaquinone), with MK-4 and MK-7 being the most researched and applicable to athletic performance.

K1 is found in all plant based foods, especially your leafy greens, and K2 is found in all types of fermented plant food and animal based foods. How important is this? Very! The different types of Vitamin K we ingest are absorbed by different parts of the body and therefore by changing the sources and type of Vitamin K we consume, we can ultimately tailor the health outcomes we want to our needs.

Vitamin K1 goes straight to the liver and aids in the essential proteins needed for blood clotting[5]. Vitamin K2 (MK-7) is probably the most researched and has been shown produce a hormone called osteocalcin within the bone[2]. This hormone has been shown to improve exercise performance, metabolic health and hormonal health [4]. Vitamin K2 (MK-4) has been shown to be absorbed more readily by our peripheral tissues and muscles, and therefore can help protect against cancer and calcium deposit in these tissues, while also promoting the production of sex hormones by directly interacting with our sex organs. It does this through specific gene expression and is probably one of the most important forms of K to be consuming[3].

Unlocking the Key to K!

Ever looked in the mirror and thought – ‘Jeeze, thanks mum and dad, I definitely wasn’t born with bodybuilder genes!!’ . Well looks like it’s not completely their fault that we aren’t building muscle as quick as we’d like to. Yes genes are passed down from generation to generation, but its what our body does with these genes that can truly unlock the key to amazing physiques. This is where Vitamin K, MK-4 comes into play.

Vitamin K MK-4 regulates gene expression in ways no other vitamin does, it turns on gene expression in some organs and turns it off in others [6]. What does this mean? It not only turns on the genes involved in cell health, and in sex organs turns on the expression of hormone production, but also turns off the genes that can cause cancer in cells [3]- resulting in healthier men and women with higher testosterone (or balanced oestrogen in women) while at the same time lowering the risk of cancer.

Because it plays such an important role in animal reproduction and health, over the generations, evolution has found a way for animals to synthesise MK-4 from Vitamin K1 and Vitamin K2 MK-7. It’s the only Vitamin K that can be synthesised and is why MK-4’s best sources are from animal products.

Where to find it and how much do I need?

I can hear you all asking ‘Nick, if we can all synthesize MK-4, why do we need to supplement with it?’ Well the reality is, we don’t really know how much humans synthesis of this vital Vitamin K form, and therefore it would be ignorant for us to rely on our own synthesis to provide us with enough MK-4 to reap the benefits [7].

I would recommend supplementing with 600micrograms a day to really benefit from MK-4, this is based on the most recent studies which suggest this dose is enough to improve gene expression. [8].

What does this look like in food? Every food is different, but 4 whole eggs contain 20micrograms, and 100g of dark chicken meat provide 60micrograms.
For those who are really adventurous – Natto (a fermented soy product from japan) and Goose Liver are extremely high sources of Vitamin K2, with 1/3oz of Natto and 2oz of Goose Liver providing 200microgram daily dosage in 1 serving. Alternatively if your finding it difficult to consume products high in K2, supplements are available in abundance.

As with all fat soluble vitamins, Vitamin K2’s absorption is best when it’s taken with a fatty meal – I personally recommend taking your Vitamin K with about 40g of fat to really optimise the absorption without causing too much gastric distress. Of course those in comp prep, or on lower fat diets will still benefit from having Vitamin K with whichever meal during the day is highest in fat.

However as with anything, if you are on any prescription medications you have to consult with your physician or doctor before starting any type of supplementation. Because of Vitamin K’s ability to affect blood clotting, you cannot supplement with it if you are taking any blood thinning medications such as warfarin.

Now my friends, go forth and add some Vitamin K supplementation to your diet. Your bones will be stronger, your hormones will be optimised and your cells will be healthier. You’ll truly see why Vitamin K is the overlooked King of the vitamin jungle.


1 – Oury F et al; Endocrine regulation of male fertility by the skeleton, Cell. 2011 Mar 4;144(5):796-809
2 – Hauschka PV; Osteocalcin: the vitamin K-dependent Ca2+-binding protein of bone matrix.. Haemostasis. Haemostasis. 1986;16(3-4):258-72.
3 – Ito A et al; Menaquinone-4 enhances testosterone production in rats and testis-derived tumor cells. Lipids Health Dis. 2011 Sep 13;10:158
4 – Oury F et al; Osteocalcin regulates murine and human fertility through a pancreas-bone-testis axis. J Clin Invest. 2013 Jun;123(6):2421-33
5 – Olson RE; Vitamin K. In: Shils M, Olson JA, Shike M, Ross AC, eds. Modern Nutrition in Health and Disease. 9th ed. Baltimore: Lippincott Williams & Wilkins; 1999:363-380.
6 – Ichikawa T et al; Vitamin K2 induces phosphorylation of protein kinase A and expression of novel target genes in osteoblastic cells. J Mol Endocrinol. 2007 Oct;39(4):239-47
7 – Sato T et al; Comparison of menaquinone-4 and menaquinone-7 bioavailability in healthy women. Nutr J. 2012 Nov 12;11:93
8 – E Nakamura et al; Low-dose menaquinone-4 improves γ-carboxylation of osteocalcin in young males: a non-placebo-controlled dose–response study. Nutr J. 2014 Aug 27;13:85

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