The power of vitamin K2: what you need to know

While most people are familiar with Vitamin K1, which is essential for blood clotting, Vitamin K2 has unique benefits that are just beginning to be fully understood.

From calcium transport to heart health, #VitaminK2 deserves a spotlight in your wellness routine. Curious? Dive into this blog to learn more. #saslife
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What is Vitamin K2?

Vitamin K2 is part of the Vitamin K family, which includes Vitamin K1 (phylloquinone) and several subtypes of Vitamin K2, known as menaquinones (MK-4 to MK-13). Unlike Vitamin K1, which is found in leafy green vegetables, Vitamin K2 is primarily found in animal products and fermented foods. This vitamin is fat-soluble, meaning it dissolves in fats and oils and can be stored in the body's fatty tissues.

Health Benefits of Vitamin K2

Bone Health

One of the most significant benefits of Vitamin K2 is its role in bone health. Vitamin K2 activates osteocalcin, a protein that helps bind calcium to the bone matrix, thereby strengthening bones and reducing the risk of fractures. Studies have shown that Vitamin K2 supplementation can improve bone mineral density and reduce the incidence of osteoporosis, particularly in postmenopausal women. Osteocalcin is also the main protein regulating dental health; while not technically bones, K2 has been shown to remineralize teeth and prevent cavities.

Heart Health

Vitamin K2 is also crucial for cardiovascular health. It helps prevent the calcification of arteries, which can lead to heart disease. By activating matrix Gla-protein (MGP), Vitamin K2 ensures that calcium is deposited in bones rather than in the arteries. Studies have found that taking K2 can slow progression of coronary artery calcification (CAC) in patients that already have CAC. Studies have linked higher Vitamin K2 intake with a reduced risk of coronary heart disease.

Cancer Prevention

Some studies have indicated that Vitamin K2 may have anti-cancer properties. It has been shown to inhibit the growth of cancer cells and induce apoptosis (programmed cell death) in certain types of cancer (liver, colorectal, ovarian, prostate, pancreatic, lung cancer and leukemia).

Other Benefits

Vitamin K2 may help with leg cramps by altering intracellular calcium levels. Additionally, its antioxidant properties help generate ATP from damaged mitochondria (specifically in neurological disease). Research also highlights its positive role in chronic kidney disease, improving renal artery function, enhancing glomerular filtration and treating liver cirrhosis. Furthermore, Vitamin K2 contributes to immune function, exhibits anti-inflammatory properties and provides protective effects against diabetes and obesity.

Sources of Vitamin K2

Vitamin K2 is found in various foods, particularly those that are fermented or animal based. We can also convert some vitamin K1 to K2, but in small amounts. It is also synthesized by bacteria in our microbiome, but the amount produced varies significantly between individuals based on their gut microbiome composition. It also seems that K2 produced by our gut is only used in the gut, so it doesn’t get absorbed and transported to other parts of our body.

The actual amounts of K2 in foods can vary widely depending on the type of bacterial strains used, fermentation conditions and duration (in fermented products like natto and cheese), as well as the animal’s diet and gut health (in animal based foods). Good sources of Vitamin K2 include:

Natto: A traditional Japanese dish made from fermented soybeans, natto is one of the richest sources of Vitamin K2. One Tablespoon contains about 150 mcg of K2.

Cheese: Certain cheeses, especially hard and aged varieties.

Egg Yolks: Eggs from pasture-raised chickens tend to have higher levels of K2.

Meat: Dark chicken meat and organ meats like liver have the highest amounts of K2, followed by pork and beef. You'll find higher levels in grass-fed, pasture-raised animals.

Eel: Eel has substantially more K2 than any other seafood, with about 63mcg in 3.5oz.

Fermented Foods: Sauerkraut, kimchi, and other fermented vegetables also provide Vitamin K2.

When looking at supplements you will typically find two different forms of Vitamin K2, MK-4 and MK-7. There is still debate on which one is “better.” MK-4 is rapidly absorbed, but also rapidly cleared from the blood stream, requiring multiple “dosing” during the day, where MK-7 remains in the blood stream longer. MK-7 supplements are usually made from natto (but not always), whereas MK-4 supplements are synthetic (but bioidentical). If you are taking blood thinners like Coumadin (Warfarin), you must talk to your health care provider before taking Vitamin K supplements.

How Much Vitamin K2 Do You Need?

Right now there are no official recommendations regarding Vitamin K2 needs, but general guidelines suggest that healthy adults should aim for 100 to 200 micrograms per day. It's important to note that Vitamin K2 works synergistically with Vitamin D and calcium, so ensuring adequate intake of these nutrients is also beneficial.

The research is far from over for Vitamin K2, as we are just now beginning to understand how important this nutrient is for our overall health. Unfortunately, right now there aren’t any great lab tests to see where your levels are, so just make sure to include food sources of K2 on a regular basis.

Cashew Chicken

Makes 8 servings
Recipe adapted from: Feasting at Home
PRINT RECIPE

Ingredients
CHICKEN
2 lbs chicken thighs or breasts, cut into 1-inch chunks
2 Tbsp cornstarch
½ tsp salt
avocado oil, for pan frying

STIR-FRY SAUCE
¼ cup low-sodium tamari or soy sauce
3 Tbsp maple syrup (or honey), adjust to taste
1 Tbsp toasted sesame oil
2 Tbsp sherry vinegar, Chinese cooking wine or rice vinegar
1 Tbsp molasses
2 tsp fresh ginger root, sliced
2 garlic cloves
½ cup chicken broth
¼ tsp Chinese 5 spice
¼ tsp white pepper, optional
pinch or two of pepper flakes or a squirt of sriracha

STIR-FRY
½ cup onion, chopped
4 large garlic cloves, roughly chopped
2 tsp fresh ginger, finely chopped
½ cup (1½ oz) shiitake mushrooms, finely chopped
2 green onions, chopped
1-2 broccoli crowns, cut into florets
1-2 bell peppers, chopped into 1-inch pieces
3/4 cup cashews, roasted, unsalted
avocado oil, for sautéing

Directions

Prepare the chicken

Add chopped chicken, cornstarch and salt to a bowl or bag. Stir or shake until fully coated.

Set aside while you prep the other ingredients.

Make the sauce

Add all stir-fry sauce ingredients to a bowl, stirring until combined.

Cook the chicken

Heat a large skillet or wok over medium-high heat with avocado oil.

Cook chicken in batches, about 1 minute on each side, or until just light brown. It will continue to cook in the sauce, so it doesn’t have to be cooked all the way through.

Set aside on a plate with a paper towel to absorb some of the oil, if needed.

Make the stir-fry

Add onion, garlic, ginger and mushrooms to skillet or wok with oil. Sauté about 3 minutes.

Add broccoli, peppers, stir-fry sauce, chicken and cashews, plus half of the green onions. Cashews will soften in the stir-fry. If you prefer they stay crunchy, add them on top after cooking - or cook half of the cashews and garnish with the other half.

Let sauce bubble for about 2 minutes.

Garnish with the rest of the green onions.

Serve over brown rice or cauliflower rice, if desired. This also makes a delicious filling for lettuce cups!