Health Benefits of Fermented Food

We are seeing more and more fermented foods available at the grocery store… why?

Vitamin K is an obscure vitamin gaining popularity in the natural health world. Well, actually Vitamin K represents a whole suit of compounds crucial for many bodily functions, particularly cardiovascular health. Like all things physiological, every part of us- from tiny cells to body systems- is interconnected. Similarly, the more we know about how the body works, the more we don’t know. The one outstanding truth for healthcare is that balance is key; too much or too little of anything sends a ripple effect throughout our interconnected beings. This article is my humble attempt at illuminating the importance of making sure you are getting adequate Vitamin K- the right kind, that is- and encouraging everyone to eat more whole plants, particularly green leafy and fermented ones.

Vitamin K is a fat-soluble group of vitamins including K1 (phylloquinone) and K2 (the menaquinones). K1 is synthesized by plants and K2 is synthesized by intestinal microbiota- that’s right, the bacteria in our guts unlocks this crucial vitamin. K2 actually comes in a range of forms differing by the number of carbon chain; for example, K-2/MK-7 is particularly studied and beneficial to human health (Bruno, 2016). Vitamin K was first studied primarily for its role in proper blood clot formation (in fact, it’s called Vitamin K because a Danish scientist first isolated this compound while studying blood coagulation, koagulation). Our body uses Vitamin K1 in the hepatic synthesis and activation of several blood clotting factors. The RDA (Recommended Dietary Allowance) in USA has only been set for K1 in response to its role in clot formation.  As our understanding of the body evolves, it would be wise to reconsider Vit K’s role beyond- but connected too- blood coagulation.

New research is showing that Vitamin K’s actions reach far beyond blood clotting. For example, one 2007 study found that K2, K3, and K5 had antitumor effects in vitro and vivo by “inducing caspasedependent (caspases are protease enzymes involved in programmed cell death and inflammation) apoptotic death of tumor cells” (Ogawa 2007). In particular, Vitamin K2 plays a key role calcium binding for maintaining proper bone and vessel health and calcium deposition.

The metabolic pathways unlocked by hormones and vitamins that unlock those hormones are dizzying, but they are helpful nonetheless in helping us better understand and appreciate our exquisitely complex and interconnected bodies. However, it is important to not get wrapped up in the jargon but really focus on the key points- and listen to your gut (literally!). Let’s looks at one way Vitamin K is essential for proper bone, heart, and blood health.

Cell membranes are damaged all the time, namely by injury, oxidation, and inflammation. When a membrane is damaged, calcium will escape to the extracellular space. Two proteins (Protein S and C4 binding protein, among others) bind to this runaway calcium and keep it from leaking elsewhere. We know that misplaced and excessive calcium cause kidney stones, gallstones, hardened arteries, and bone spurs among other things. Protein S and C4 can’t do their job handling calcium without Vitamin K. Certain Inflammatory conditions like hypocomplimentemia (state of deficient Compliment protein in the blood) result when Protein S can’t be activated. Additionally, without Vitamin K2, all that misplaced calcium can aggravate your cardiovascular systems and bones. Vitamin K2, used in conjunction with Vitamin D, has been shown to slow the progression of atherosclerosis in persons with jeopardized cardiovascular and kidney function. K2 appears to protect vessels from damage because it activates calcification inhibitors like osteocalcin (OC) and matrix GLA protein (MGP) (Kurnatowska et al. 2015).

It might be the case that the majority of the population is deficient in Vitamin K. Why? Because this vitamin is the byproduct of particular bacterial activity in our guts. Since our modern world is largely fed a rather pasteurized and processed diet, it is uncommon for a person to receive the adequate amount of nutrient-rich, living, fermented foods. I mention fermented foods here because they are the densest reservoir of Vitamin K. You can purchase supplements of bioavailable Vitamin K that are effective, or you could enhance your diet with more live ferments.

Even more complicated than our bodies is the amount of contradictory scientific evidence arguing for or against the next herb, vitamin, or drug in the spotlight. For me, it makes the most sense to return to the source in order to find the answer; then, I supplement by researching credible sources.  For example, if Vitamin K is so rampant in live fermented foods and our ancestors survived by consuming mostly fermented foods (because they had little in the way of modern food processes and preservatives), then I trust that Vitamin K is likely lacking in the modern diet. If you suffer from hardening of the arteries, calcium deposits, bone spurs, kidney stones and all things that involved misplaced calcium, you would be wise to discuss Vitamin K supplementation with a natural healthcare practitioner whom you trust. Rich sources of Vitamin K1 included green leafy vegetables like kale, collards, and spinach. K2 can be found in cheese curds, natto (this is strong-tasting stuff, but the flavor grows on you!), and any live-fermented food. Get in the practice of eating something fermented every day, even if it is just a spoonful of sauerkraut or swig of kefir with dinner. Only grass-fed dairy (at all costs, try to avoid antibiotic-laden and inhumane CAFOs, confined animal feeding operations) provides products rich with K2. Since Vitamin K is fat soluble, it’s important to eat it with a fat source. Additionally, if you are taking antibiotics, your Vitamin K reservoir is likely depleted (remember that K2 is made by gut bacteria, most of which are killed by antibiotics). The verdict is still out, but the ideal amount of Vitamin K is 360-500 mcg/day. In the Rotterdam study (the first official look at the value of Vitamin K on long-term cardiovascular health), people who had 45 mcg of K2 lived 7 years longer than those taking 12 mcg per day. There are no real threats of Vitamin K toxicity yet, unless you are taking certain medications.

The bottom line is that Vitamin K deficiency is prolific in our modern world and you are wise to start supplementing your diet with it, particularly if you already battle with poor cardiovascular health, kidney function, or show signs of calcium deposits elsewhere. Everyone can benefit from eating more fermented foods and green leafy vegetables, so pull out your big jars, buy some cabbage, carrots, and radishes, and start making your own live ferments today! Eat more ferments, O-K?

            (If you are on or have been taking any medications like antibiotics, blood-thinners, or pills for weight loss, please consult your doctor before starting any new vitamin regime). For more information on making wild ferments at home, check out Sandor Katz’s page.

Blog by Eileen Schaeffer, Certified Herbalist (BRSHM, C’16) and Assistant Manager of Remedy Herb Shop. Please come by Remedy Wednesday through Saturday and meet Eileen- she can answer any questions about fermented food and beyond!


Bruno, Gene. New Research on Vitamin K2. Supplement Science. 2016 May.

Kurnatowska I, Grzelak P, Masajtis Zagajewska A, Kaczmarska M, Stefańczyk L, Vermeer C, Maresz K, Nowicki M. Effect of vitamin K2 on progression of atherosclerosis and vascular calcification in nondialyzed patients with chronic kidney disease stage 35. Pol Arch Med Wewn. 2015 Jul 15. pii: AOP_15_066.

Mercola, Joseph. 11 January 2015. website

Ogawa, Mutsumi, et al. “Vitamins K2, K3 and K5 exert antitumor effects on established colorectal cancer in mice by inducing apoptotic death of tumor cells.” International journal of oncology 31.2 (2007): 323-332.

Schurgers, L. J., et al. “Nutritional intake of vitamins K1 (phylloquinone) and K2 (menaquinone) in the Netherlands.” Journal of nutritional & environmental medicine 9.2 (1999): 115-122.