This text was beforehand printed November 11, 2019, and has been up to date with new data.
Vitamin Ok is a fat-soluble vitamin with vital well being affect that many do not get sufficient of. Your physique shops little or no of it, so it is quickly depleted with out common dietary consumption. Frequent medicine also can deplete vitamin Ok, making elevated consumption much more essential.
There are various vitamin Ok-dependent proteins in your physique, that are concerned in issues like blood coagulation, bone metabolism and mineralization of your blood vessels. As you’d suspect, which means vitamin Ok performs a very essential position within the prevention of bleeding issues, osteoporosis and coronary heart illness.
There are two important types of vitamin Ok, together with a number of subtypes, all of which might make issues a bit complicated. Right here, I am going to do my greatest to interrupt down the fundamentals, beginning with the naturally-occurring types of vitamin Ok and their primary capabilities and sources:1,2
1. Vitamin K1 (phylloquinone) — Vitamin K1 is derived from inexperienced, leafy greens corresponding to spinach, kale, broccoli and cabbage, and is greatest identified for the position it performs in blood clotting.
With inadequate K1, your blood can’t clot correctly, which might have life-threatening penalties, as you could possibly bleed to loss of life. Extreme consumption of dietary or supplemental K1 nonetheless, can overcome the anticoagulant results of blood thinning medicines.
As famous by vitamin Ok knowledgeable Leon Schurgers, Ph.D., absorption of vitamin K1 from meals is low; solely 10% of the vitamin Ok present in greens is absorbed, and there isn’t any option to considerably improve that absorption.
2. Vitamin K2 (menaquinones) — The menaquinones play a major position in bone and coronary heart well being. Inside your physique, vitamin K2 is synthesized by sure micro organism in your intestine. There are a number of subtypes of K2, two of the most typical of that are:3
a. Menaquinone-4 (MK-4) — A brief-chain type of vitamin K2 present in animal merchandise corresponding to meat, eggs, liver and dairy.4,5 Supply issues, nonetheless. For instance, pasteurized dairy and merchandise from manufacturing unit farmed animals aren’t excessive in MK-4 and must be prevented. Solely grass fed animals (not grain fed) will develop naturally excessive ranges.
MK-4 has a brief organic half-life — about 2.5 hours — making it a poor candidate as a dietary complement. That mentioned, pure MK-4 from meals is essential for good well being because it performs a task in gene expression. For instance, analysis6 has discovered it might decrease your danger of liver most cancers.
b. Menaquinone-7 (MK-7) — Longer-chained vitamin K2 present in fermented meals corresponding to sauerkraut, sure cheeses and natto.7 There’s a wide range of these long-chain types, however the most typical one is MK-7. That is the one you may wish to search for in dietary supplements, as this kind is extracted from actual meals, particularly natto,8 a fermented soy product.
MK-7 is produced by particular micro organism throughout the fermentation course of. Nonetheless, not all strains of micro organism make it,9 so not all fermented meals will present it. Most industrial yogurts, for instance, are just about devoid of vitamin K2, and whereas sure sorts of cheeses, corresponding to Gouda, Brie and Edam, are excessive in K2, others aren’t.
Among the finest methods to make sure a superb supply of vitamin K2 is to ferment your individual greens utilizing a particular starter tradition with bacterial strains that produce vitamin K2. Whereas K1 in greens is poorly absorbed, just about all the K2 in fermented meals is available to your physique.
The MK-7 fashioned within the fermentation course of has two main benefits: It stays in your physique longer and has an extended half-life than MK-4,10 which suggests you possibly can take it simply as soon as a day.
Analysis11 has proven MK-7 helps stop irritation by inhibiting proinflammatory markers that may trigger autoimmune ailments like rheumatoid arthritis. And, whereas vitamin K1 has been discovered to reasonably cut back the chance of bone fractures,12 MK-7 is simpler than vitamin K1 at reaching (and defending) your bone.13,14
Vitamin K2 Performs Key Function in Coronary heart Well being
The distinction between nutritional vitamins K1 and K2 was clearly established in The Rotterdam Examine,15 printed in 2004, which centered on their results on the center. Because it seems, K1 has no impact on the center in any respect, whereas K2 does.
That does not imply K1 is ineffective — removed from it. In line with a 2019 research16 within the Journal of Gerontology, older people with low vitamin K1 standing usually tend to have mobility issues and incapacity than these with increased ranges. In actuality, you want the entire suite of vitamin Ok, however vitamin K2 does have essential advantages that K1 doesn’t.
One of many the explanation why vitamin K2 is so essential for each bone and coronary heart well being specifically has to do with a posh biochemistry involving the enzymes matrix gla-protein (MGP, present in your vascular system17), and osteocalcin, present in your bone.
“Gla” stands for glutamic acid, which binds to calcium within the cells of your arterial wall and removes it from the liner of your blood vessels. As soon as eliminated out of your blood vessel lining, vitamin K2 then facilitates the combination of that calcium into your bone matrix by handing it over to osteocalcin, which in flip helps “cement” the calcium in place inside your bone.
Vitamin K2 prompts these two proteins, so with out it, this switch means of calcium out of your arteries to your bone can’t happen, which raises your danger of arterial calcification.18
Calcium deposits within the arteries are liable for atherosclerosis, hardening and narrowing of the arteries, slowly blocking blood circulation. It is a frequent reason for coronary heart assaults, strokes and peripheral vascular illness.
Certainly, research19,20 have demonstrated vitamin K2 inhibits arterial calcification and improves arterial flexibility, thereby lowering your danger of a cardiovascular occasion (corresponding to a coronary heart assault) or loss of life.21
One 2019 research22 proposed therapeutic supplementation with vitamin K2 might stop or halt development of vascular calcification that will happen with extreme calcium consumption, and former analysis has demonstrated these consuming the very best quantity of vitamin K2 have the bottom danger of growing heart problems.
Within the Rotterdam research,23 those that had the very best quantity of vitamin K2 have been 52% much less prone to expertise extreme calcification of their arteries and 57% much less prone to die from coronary heart illness over a seven- to 10-year interval.
Individuals who consumed 45 micrograms (mcg) of K2 every day lived on common seven years longer than folks getting simply 12 mcg per day. This was a profound discovery, as a result of such a correlation didn’t exist for K1 consumption.
In a subsequent trial referred to as the Prospect Examine,24 16,057 girls have been adopted for a mean of 8.1 years. Right here, they discovered that every further 10 mcg of K2 within the weight loss plan resulted in 9% fewer cardiac occasions. Once more, vitamin K1 had no obvious impression on coronary heart illness danger.
Vitamin K2 Is an Essential Ally In opposition to Osteoporosis
To elucidate the significance of vitamin K2 for bone well being and prevention of osteoporosis a bit additional, this goes again to its affect over osteocalcin.25 Osteocalcin is a protein produced by your osteoblasts (cells liable for bone formation), and is utilized inside the bone as an integral a part of the bone-forming course of.
Nonetheless, osteocalcin should be “carboxylated” earlier than it may be efficient. Vitamin Ok capabilities as a cofactor for the enzyme that catalyzes the carboxylation of osteocalcin.
A scientific assessment and meta-analysis26 printed in 2006 discovered vitamin K2, on this case MK-4, diminished bone loss and had “a robust impact on incident fractures.” MK-4 supplementation was linked to a 60% discount in vertebral fractures, a 77% discount in hip fractures and an 81% decrease danger for all nonvertebral fractures.
One other three-year-long placebo-controlled research27 executed within the Netherlands discovered that postmenopausal girls taking 180 mcg of MK-7 per day elevated their bone power, decreased the speed of age-related bone mineral decline and diminished bone density loss, in comparison with placebo.
Vitamin K2 ‘Kills Two Birds With One Stone’
Oftentimes, osteoporosis (precipitated by inadequate calcium in your bones) goes hand in hand with coronary heart illness, and vitamin K2’s interrelationship with MGP and osteocalcin is without doubt one of the causes for that.
In brief, each osteoporosis and coronary heart illness are associated to vitamin K2 deficiency, and could be prevented by making certain adequate quantities.
As famous in a 2015 paper,28 “By putting the precise stability in consumption of calcium and K2, it might be potential to battle osteoporosis and concurrently stop the calcification and stiffening of the arteries.”
The next graphic from the 2014 paper,29 “Vitamin Ok: An Outdated Vitamin in a New Perspective,” illustrates the impact of vitamin Ok on bone and vascular well being.
Remember the fact that vitamin K2 additionally works in tandem with vitamin D and magnesium. So, it is essential to do not forget that vitamin K2 must be thought of together with calcium, vitamin D and magnesium, as these 4 all have a synergistic relationship that impacts your bone and coronary heart well being.30
Different Well being Advantages of Vitamin K2
Vitamin K2 can also be essential for a wide range of different well being causes and situations, together with the next:
Dental well being — Preserving enamel helps cut back cavity formation. Your enamel is manufactured from hole tubes that reach into the dentin. The enamel is manufactured from nonliving cells, whereas the dentin has dwell cells referred to as odontoblasts.
These cells launch proteins utilizing vitamin K2 to assist stop tooth decay by an immune response.31 Analysis32 has demonstrated osteocalcin could also be present in infected tissue, and researchers take into account the protein to have a reparative position in dental pulp.
You enamel, like your bones, are storehouses of calcium, which helps the construction and hardness of the enamel.33 The best way calcium is deposited in your enamel will both improve the hardness of your tooth or make it extra brittle.
Vitamin K2 as soon as once more acts just like the site visitors cop, telling calcium the place and the way for use in your enamel. Working along with vitamin D, it additionally promotes a discount in tooth decay or cavities.34
Most cancers — Most cancers prevention is one other well being good thing about vitamin K2. As famous within the 2010 European Potential Investigation into Most cancers and Diet (EPIC) research,35 excessive consumption of vitamin K2 — not K1 — reduces most cancers danger and lowers most cancers mortality by 28%. Findings printed in 2008 confirmed males who consumed the best quantities of K2 had a 63% diminished incidence of superior prostate most cancers.36
The proof additionally suggests vitamin K2 might cut back your danger for Non-Hodgkin lymphoma. Mayo Clinic researchers found that folks with the very best consumption of vitamin K2 (108 mcg/day or increased) had a forty five% decrease danger for any such most cancers, in comparison with these with the bottom vitamin K2 consumption (39 mcg/day or much less).37
They attribute this impact to vitamin K2’s potential to inhibit inflammatory cytokines, that are associated to any such lymphoma, and its position the life cycle of your cells.
Inflammatory situations — The inflammatory response is an important element in lots of persistent ailments and ailments of getting older. Scientific proof suggests each vitamin K1 and K2 have anti-inflammatory exercise, partly by inhibiting nuclear issue kappa-B.38
In a single meta-analysis,39 researchers discovered proof the household of vitamin Ok performs a protecting position in persistent getting older situations, irritation and heart problems. One other research40 confirmed the position the MK-7 kind particularly has within the modulation of inflammatory biomarkers.
The researchers evaluated pure vitamin K2 for its potential to inhibit gene expression and manufacturing of pro-inflammatory markers in vitro, discovering MK-7 inhibited gene expression in a dose-dependent method.
Different analysis41 has demonstrated a discount in C-reactive protein, a standard biomarker used to guage irritation in sufferers with rheumatoid arthritis. C-reactive protein is a danger marker for a variety of ailments and the researchers concluded increased consumption of vitamin K2 might decrease general danger.
Kidney well being — There’s additionally accumulating proof suggesting vitamin K2 might play a task in persistent kidney illness.
A pre- and post-intervention scientific trial,42 which included sufferers with a prognosis of persistent kidney illness who took 360 mcg of MK-7 for 4 weeks, discovered it considerably diminished calcification within the sufferers’ blood vessels.
Sufferers with persistent kidney illness with a subclinical vitamin Ok deficiency might also profit from a better consumption of the vitamin.43 As famous in a 2016 research44 in EBioMedicine, “MGP not solely inhibits calcification in bigger arteries but additionally could also be renoprotective.”
Testosterone — Yet one more position vitamin K2 performs in your physique is the optimum manufacturing of intercourse hormones. A minimum of two research45,46 have proven MK-4, present in animal meals corresponding to meat and dairy merchandise, can assist stability testosterone manufacturing.
Polycystic ovarian syndrome (PCOS) — Vitamin K2 has an impact in girls as nicely, because the vitamin could also be useful within the administration of PCOS. That is now the most typical hormonal issues in younger girls, inflicting enlarged ovaries and a heightened danger for fertility issues.47
In a single randomized research,48 60 vitamin D poor girls with PCOS took both a placebo or a mix of calcium, vitamin D and vitamin Ok for eight weeks. These within the therapy group loved better lower in testosterone and signs than the placebo group.
Insulin sensitivity — An surprising discovery was made when researchers discovered bone was an endocrine organ, contributing to the regulation of a lot of physiological processes, together with glucose homeostasis.49
There’s proof to counsel vitamin K2 supplementation might enhance insulin sensitivity by way of osteocalcin metabolism,50 and should assist stop the event of Kind 2 diabetes.51
The proof isn’t conclusive, nonetheless, as a scientific assessment52 of managed trials discovered K2 supplementation had no impact on insulin sensitivity. A part of the issue might have one thing to do with the type of vitamin given. Quite a few research have demonstrated artificial vitamin K2 dietary supplements aren’t as efficient as natto-derived K2 dietary supplements.
Mitochondrial well being — Analysis53 printed within the journal Science in 2012 discovered vitamin K2 serves as a mitochondrial electron provider, thereby serving to keep regular ATP manufacturing in mitochondrial dysfunction, corresponding to that present in Parkinson’s illness.
Macular degeneration — In line with a 2014 paper54 on vitamin Ok, MK-7 specifically might provide advantages for age-related macular degeneration.
Indicators and Signs of Vitamin K2 Deficiency
The most important downside we face in terms of optimizing vitamin K2 is that there isn’t any straightforward option to display or check for vitamin K2 sufficiency. Vitamin K2 can’t at current be measured immediately, so it is measured by an oblique evaluation of undercarboxylated osteocalcin. This check remains to be not commercially obtainable, nonetheless.
With out testing, we’re left with numerous way of life components that predispose you to deficiency. As a normal rule, when you’ve got osteoporosis, coronary heart illness or diabetes, you are possible poor in vitamin K2.
That mentioned, it is believed that the overwhelming majority of individuals are in actual fact poor nowadays and would profit from extra K2. One cause for it’s because only a few (People specifically) eat sufficient vitamin K2-rich meals.
So, in case you would not have any of the well being situations listed, however don’t commonly eat excessive quantities of the next meals, then your chance of being vitamin K2 poor remains to be very excessive:
- Sure fermented meals corresponding to natto, or greens fermented utilizing a starter tradition of vitamin K2-producing micro organism
- Sure cheeses corresponding to Brie and Gouda (these two are significantly excessive in K2)
- Grass fed natural animal merchandise corresponding to egg yolks, liver, butter and dairy
Use of sure medicine might also have an effect on your vitamin K2 standing and make you extra susceptible to deficiency. For instance, analysis55 exhibits statins deplete vitamin K2, and there is scientific proof56 suggesting statin medicine might certainly improve calcification within the arteries.
Vitamin K2 depletion could also be a proof for that. So, in case you’re on a statin, you may wish to be sure to’re taking additional vitamin K2, in addition to ubiquinol or coenzyme Q10, which can also be being depleted by the drug.
As mentioned in “Vitamin K2 Deficiency Is a Vital Explanation for Cardiovascular Illness,” warfarin, antibiotics, anti-tuberculosis medicine, anticonvulsants also can increase your danger of vitamin Ok deficiency.
As for a clinically helpful dosage of vitamin K2, some research — together with the Rotterdam research57 — have proven as little as 45 mcg per day could also be adequate. As a normal guideline, I like to recommend getting round 150 mcg of vitamin K2 per day.
Others suggest barely increased quantities; upward of 180 to 200 mcg. Happily, you needn’t fear about overdosing on K2, because it seems to be fully unhazardous.
In the event you go for a vitamin K2 complement, ensure it is MK-7. (The exception is in case you’re on vitamin Ok antagonists, i.e., medicine that cut back blood clotting by lowering the motion of vitamin Ok. In that case, you need to keep away from MK-7 dietary supplements.58) Additionally bear in mind to take it with fats because it’s fat-soluble and will not be correctly absorbed in any other case, and to stability it with calcium, vitamin D and magnesium.
As a final tip, needless to say vitamin K2 might not essentially make you “really feel higher” per se. Its inside workings are such that you simply’re not prone to really feel the distinction bodily.
Compliance can due to this fact be an issue, as individuals are extra prone to take one thing that has a noticeable impact. This will likely not occur with vitamin K2, however that definitely doesn’t imply it is not doing something.