Author: Kate Scott, DipNut, mBANT, rCNHC, mIFM – DNApal co-founder | Nutrition & genetics specialist | BANT registered nutritionist

Understanding vitamin K

Vitamin K is one of the fat-soluble vitamins (along with vitamins A, D and E). It has two main forms: vitamin K1 (phylloquinone) and vitamin K2 (menaquinone (MK)). K1 is the predominant form of vitamin K found in the diet in the form of green veggies, while K2 is produced by bacteria in our gut and can also be obtained from some animal-derived sources and fermented foods (where bacteria are part of the process).

The Benefits:

Blood Clotting:

The most well-known role of vitamin K is assisting in healthy blood clotting (coagulation). It helps activate particular proteins that make sure our blood clots properly. Low levels of Vitamin K can lead to excessive bleeding and longer healing times.

Bone Health:

Vitamin K also helps to regulate calcium by activating proteins that deposit calcium into your bones, making them nice and sturdy.

While vitamin D3 (Read our “Vitamin D: Nutrition Nitty-Gritty” blog post) helps increase calcium absorption from the intestines, vitamin K assists in directing calcium to the bones and teeth, preventing it from accumulating in the arteries and soft tissues.

This is why it is important for supplements to combine both vitamin K and vitamin D3 to help keep your bones strong and lower your risk of osteoporosis.

Cardiovascular Health:

Vitamin K2 helps to prevent something called “calcification” (the buildup of calcium plaque) in the arteries (a). Calcification is the main cause of heart attacks. So, let’s give a big thumbs up to vitamin K for keeping our hearts happy and healthy.

Brain Function:

New studies are showing that vitamin K might be a brain booster. It’s believed to do wonders for our cognitive function and might even help lower the risk of brain disorders like Alzheimer’s disease (b).

Vitamin K-rich foods:

If you want to make sure you’re getting enough vitamin K, it’s a good idea to include foods that are packed with this nutrient in your diet. Check out these fantastic sources of vitamin K:

Dark Leafy Greens: Kale, spinach, Swiss chard, and broccoli are packed with vitamin K1, making them excellent choices for boosting your intake.

Cruciferous Vegetables: Brussels sprouts and cabbage are rich in vitamin K1 and provide other valuable nutrients.

Natto: This traditional Japanese dish made from fermented soybeans is an exceptional source of vitamin K2.

Fermented Foods: Certain fermented foods like sauerkraut, kimchi, and fermented cheeses contain vitamin K2 produced by bacterial fermentation.

Animal-Derived Sources: Foods like egg yolks, liver, and certain types of cheese contain vitamin K2 in the form of menaquinone.

RDA UK:

The recommended daily allowance (RDA) for vitamin K in the United Kingdom varies depending on the age group. The reference nutrient intake (RNI) is used in the UK to estimate the amount of a nutrient sufficient to meet the needs of most individuals in a particular population:

Infants (0-12 months): 4-15 micrograms per day

Children (1-18 years): 25-75 micrograms per day

Adults (19 years and older): 70-120 micrograms per day

These values are general recommendations and may vary depending on individual circumstances, such as specific health conditions or pregnancy.

Additional factors to consider:

Fat intake:

Vitamin K is a type of fat-soluble vitamin, meaning it needs some dietary fat to be absorbed properly by our bodies. If you want to make sure you’re getting the most out of your Vitamin K, try eating it with some healthy fats or taking Vitamin K supplements while enjoying a meal with some fat. That way, your body can absorb it better.

Bile production:

Our liver produces a substance called bile, which is stored in our gallbladder. Bile plays a crucial role in helping our bodies absorb fat-soluble vitamins, including vitamin K. But here’s the thing: if something goes wonky with bile production or the gallbladder’s function (or if your gallbladder has been removed), it can affect how well our bodies can absorb vitamin K.

Gut microbiome and health:

Our gut microbiota is like a whole community of bacteria, and some of these friendly gut bacteria help us produce and absorb vitamin K2. So, if we want to make sure we’re making enough vitamin K, we’ve got to take care of those beneficial gut bacteria. How can we do that? Well, by making sure to include plenty of pre and probiotic foods. That way, we can keep our gut microbiome diverse and balanced and give ourselves a better chance at absorbing all the vitamin K goodness.

Additionally, certain gastrointestinal (GI) disorders like Crohn’s disease, coeliac disease, or conditions that mess with our fat digestion and absorption can make it harder for our bodies to absorb those essential fat-soluble vitamins, like vitamin K. The good news is that by taking care of our GI health and managing those conditions, we can give ourselves the best shot at absorbing all the vitamin K goodness we need.

Check out our blog post on gut health for more info: “What exactly is the gut microbiome”.

Medications:

Some medications can affect how your body absorbs vitamin K. For instance, broad-spectrum antibiotics can mess with the helpful bacteria in your gut that produce vitamin K. Similarly, there are certain cholesterol-lowering drugs, like bile acid sequestrants, which can grab onto fat-soluble vitamins, making it harder for your body to soak them up. Be aware of these interactions when taking medications to ensure you get all the necessary vitamins.

The anticoagulant drug, Warfarin, works by interfering with the action of vitamin K to prevent blood clots. So, warfarin and vitamin K work against each other and must be kept in balance. If you have been prescribed Warfarin (or any anticoagulant medication), you should not take vitamin K supplements but can continue to eat a normal, varied diet that includes vitamin K-rich foods. Always check with your doctor.

Your genes:

Of course, your genes also play a role in your need for vitamin K. The VKORC1 gene is responsible for converting inactive vitamin K (called vitamin K epoxide) into active vitamin K. This is an important step in blood clotting. Variations in this gene lead to lower levels of active vitamin K, and, therefore, risk of bleeding. Variants on this gene can also impact response to anticoagulant medications (c).

Another gene, CYP4F2, is responsible for breaking down and removing active vitamin K. Variants on this gene can result in lower active vitamin K and reduced vitamin-k dependent clotting factors, therefore increasing the risk of bleeding. This gene can also impact response to anticoagulant medications (d).

Conclusion:

Even though vitamin K often gets overlooked compared to other vitamins, it is pretty important for our health. Not only does it help with blood clotting and bone health, it may also positively affect our cardiovascular and brain health. The good news is that we can easily boost our intake of this essential nutrient by adding more vitamin K-rich foods or by taking supplements that include vitamin K. So, let’s make sure we’re giving vitamin K the attention it deserves and unlocking all its fantastic health benefits!

Our genes significantly influence how we absorb, convert and use nutrients. So order a DNApal test today to learn more about your unique needs and relieve some of the guesswork!

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