This text was beforehand printed November 11, 2019, and has been up to date with new data.
Vitamin Okay is a fat-soluble vitamin with important 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. Widespread medication also can deplete vitamin Okay, making elevated consumption much more vital.
There are a lot of vitamin Okay-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, meaning vitamin Okay performs a very vital position within the prevention of bleeding problems, osteoporosis and coronary heart illness.
There are two essential types of vitamin Okay, together with a number of subtypes, all of which might make issues a bit complicated. Right here, I will do my finest to interrupt down the fundamentals, beginning with the naturally-occurring types of vitamin Okay and their fundamental capabilities and sources:1,2
1. Vitamin K1 (phylloquinone) — Vitamin K1 is derived from inexperienced, leafy greens equivalent to spinach, kale, broccoli and cabbage, and is finest 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 would bleed to dying. Extreme consumption of dietary or supplemental K1 nonetheless, can overcome the anticoagulant results of blood thinning medicines.
As famous by vitamin Okay professional Leon Schurgers, Ph.D., absorption of vitamin K1 from meals is low; solely 10% of the vitamin Okay present in greens is absorbed, and there is no method to considerably enhance that absorption.
2. Vitamin K2 (menaquinones) — The menaquinones play a main 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 commonest of that are:3
a. Menaquinone-4 (MK-4) — A brief-chain type of vitamin K2 present in animal merchandise equivalent to meat, eggs, liver and dairy.4,5 Supply issues, nonetheless. For instance, pasteurized dairy and merchandise from manufacturing facility farmed animals usually are not excessive in MK-4 and needs to be averted. 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 vital for good well being because it performs a job in gene expression. For instance, analysis6 has discovered it could decrease your danger of liver most cancers.
b. Menaquinone-7 (MK-7) — Longer-chained vitamin K2 present in fermented meals equivalent to sauerkraut, sure cheeses and natto.7 There’s quite a lot of these long-chain types, however the commonest one is MK-7. That is the one you will need to search for in dietary supplements, as this manner is extracted from actual meals, particularly natto,8 a fermented soy product.
MK-7 is produced by particular micro organism through the fermentation course of. Nonetheless, not all strains of micro organism make it,9 so not all fermented meals will present it. Most business yogurts, for instance, are nearly devoid of vitamin K2, and whereas sure sorts of cheeses, equivalent to Gouda, Brie and Edam, are excessive in K2, others usually are not.
Top-of-the-line methods to make sure a superb supply of vitamin K2 is to ferment your personal greens utilizing a particular starter tradition with bacterial strains that produce vitamin K2. Whereas K1 in greens is poorly absorbed, nearly the entire 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 may take it simply as soon as a day.
Analysis11 has proven MK-7 helps stop irritation by inhibiting proinflammatory markers that may trigger autoimmune illnesses like rheumatoid arthritis. And, whereas vitamin K1 has been discovered to reasonably cut back the danger of bone fractures,12 MK-7 is simpler than vitamin K1 at reaching (and defending) your bone.13,14
Vitamin K2 Performs Key Position 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 keeping with a 2019 examine16 within the Journal of Gerontology, older people with low vitamin K1 standing usually tend to have mobility issues and incapacity than these with larger ranges. In actuality, you want the entire suite of vitamin Okay, however vitamin K2 does have vital advantages that K1 doesn’t.
One of many the explanation why vitamin K2 is so vital for each bone and coronary heart well being particularly has to do with a fancy 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 mixing 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 technique 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 movement. It is a frequent explanation 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 (equivalent to a coronary heart assault) or dying.21
One 2019 examine22 proposed therapeutic supplementation with vitamin K2 might stop or halt development of vascular calcification which will happen with extreme calcium consumption, and former analysis has demonstrated these consuming the best quantity of vitamin K2 have the bottom danger of creating heart problems.
Within the Rotterdam examine,23 those that had the best quantity of vitamin K2 have been 52% much less more likely to expertise extreme calcification of their arteries and 57% much less more likely 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 known as the Prospect Examine,24 16,057 ladies have been adopted for a median of 8.1 years. Right here, they discovered that every further 10 mcg of K2 within the weight-reduction plan resulted in 9% fewer cardiac occasions. Once more, vitamin K1 had no obvious affect on coronary heart illness danger.
Vitamin K2 Is an Necessary 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 Okay capabilities as a cofactor for the enzyme that catalyzes the carboxylation of osteocalcin.
A scientific overview and meta-analysis26 printed in 2006 discovered vitamin K2, on this case MK-4, lowered bone loss and had “a powerful 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 examine27 performed within the Netherlands discovered that postmenopausal ladies taking 180 mcg of MK-7 per day elevated their bone energy, decreased the speed of age-related bone mineral decline and lowered 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 among the causes for that.
In brief, each osteoporosis and coronary heart illness are associated to vitamin K2 deficiency, and will be prevented by making certain ample quantities.
As famous in a 2015 paper,28 “By placing the appropriate steadiness in consumption of calcium and K2, it could be attainable to combat osteoporosis and concurrently stop the calcification and stiffening of the arteries.”
The next graphic from the 2014 paper,29 “Vitamin Okay: An Previous Vitamin in a New Perspective,” illustrates the impact of vitamin Okay on bone and vascular well being.
Understand that vitamin K2 additionally works in tandem with vitamin D and magnesium. So, it is vital 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 be vital for quite a lot of different well being causes and circumstances, together with the next:
Dental well being — Preserving enamel helps cut back cavity formation. Your enamel is made from hole tubes that reach into the dentin. The enamel is made from nonliving cells, whereas the dentin has reside cells known as odontoblasts.
These cells launch proteins utilizing vitamin K2 to assist stop tooth decay by means of an immune response.31 Analysis32 has demonstrated osteocalcin could also be present in infected tissue, and researchers think about 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 enhance 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 Vitamin (EPIC) examine,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% lowered 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 best consumption of vitamin K2 (108 mcg/day or larger) had a forty five% decrease danger for this kind of 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 capacity to inhibit inflammatory cytokines, that are associated to this kind of lymphoma, and its position the life cycle of your cells.
Inflammatory circumstances — The inflammatory response is a vital part in lots of persistent illnesses and illnesses of ageing. 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 Okay performs a protecting position in persistent ageing circumstances, irritation and heart problems. One other examine40 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 illnesses and the researchers concluded larger consumption of vitamin K2 might decrease total danger.
Kidney well being — There’s additionally accumulating proof suggesting vitamin K2 might play a job in persistent kidney illness.
A pre- and post-intervention scientific trial,42 which included sufferers with a analysis of persistent kidney illness who took 360 mcg of MK-7 for 4 weeks, discovered it considerably lowered calcification within the sufferers’ blood vessels.
Sufferers with persistent kidney illness with a subclinical vitamin Okay deficiency might also profit from a larger consumption of the vitamin.43 As famous in a 2016 examine44 in EBioMedicine, “MGP not solely inhibits calcification in bigger arteries but in addition could also be renoprotective.”
Testosterone — One more position vitamin K2 performs in your physique is the optimum manufacturing of intercourse hormones. No less than two research45,46 have proven MK-4, present in animal meals equivalent to meat and dairy merchandise, will help steadiness testosterone manufacturing.
Polycystic ovarian syndrome (PCOS) — Vitamin K2 has an impact in ladies as properly, because the vitamin could also be useful within the administration of PCOS. That is now the commonest hormonal problems in younger ladies, inflicting enlarged ovaries and a heightened danger for fertility issues.47
In a single randomized examine,48 60 vitamin D poor ladies with PCOS took both a placebo or a mix of calcium, vitamin D and vitamin Okay for eight weeks. These within the therapy group loved larger 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 recommend vitamin K2 supplementation might enhance insulin sensitivity through osteocalcin metabolism,50 and will assist stop the event of Kind 2 diabetes.51
The proof is just not conclusive, nonetheless, as a scientific overview52 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 usually are not 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 service, thereby serving to keep regular ATP manufacturing in mitochondrial dysfunction, equivalent to that present in Parkinson’s illness.
Macular degeneration — In keeping with a 2014 paper54 on vitamin Okay, MK-7 particularly might provide advantages for age-related macular degeneration.
Indicators and Signs of Vitamin K2 Deficiency
The foremost downside we face in the case of optimizing vitamin K2 is that there is no simple method to display screen or take a look at for vitamin K2 sufficiency. Vitamin K2 can’t at current be measured instantly, so it is measured by means of an oblique evaluation of undercarboxylated osteocalcin. This take a look at continues to be not commercially obtainable, nonetheless.
With out testing, we’re left with taking a look at numerous way of life components that predispose you to deficiency. As a basic rule, if in case you have osteoporosis, coronary heart illness or diabetes, you are doubtless poor in vitamin K2.
That mentioned, it is believed that the overwhelming majority of individuals are in truth poor as of late and would profit from extra K2. One cause for it’s because only a few (Individuals particularly) eat sufficient vitamin K2-rich meals.
So, should you should not have any of the well being circumstances listed, however don’t frequently eat excessive quantities of the next meals, then your probability of being vitamin K2 poor continues to be very excessive:
- Sure fermented meals equivalent to natto, or greens fermented utilizing a starter tradition of vitamin K2-producing micro organism
- Sure cheeses equivalent to Brie and Gouda (these two are notably excessive in K2)
- Grass fed natural animal merchandise equivalent to egg yolks, liver, butter and dairy
Use of sure medication might also have an effect on your vitamin K2 standing and make you extra vulnerable to deficiency. For instance, analysis55 reveals statins deplete vitamin K2, and there is scientific proof56 suggesting statin medication might certainly enhance calcification within the arteries.
Vitamin K2 depletion could also be a proof for that. So, should you’re on a statin, you will need to ensure you’re taking additional vitamin K2, in addition to ubiquinol or coenzyme Q10, which can be being depleted by the drug.
As mentioned in “Vitamin K2 Deficiency Is a Important Explanation for Cardiovascular Illness,” warfarin, antibiotics, anti-tuberculosis medication, anticonvulsants also can increase your danger of vitamin Okay deficiency.
As for a clinically helpful dosage of vitamin K2, some research — together with the Rotterdam examine57 — have proven as little as 45 mcg per day could also be ample. As a basic guideline, I like to recommend getting round 150 mcg of vitamin K2 per day.
Others suggest barely larger quantities; upward of 180 to 200 mcg. Happily, you needn’t fear about overdosing on K2, because it seems to be utterly unhazardous.
When you go for a vitamin K2 complement, be certain it is MK-7. (The exception is should you’re on vitamin Okay antagonists, i.e., medication that cut back blood clotting by lowering the motion of vitamin Okay. In that case, you must 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 steadiness 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 inner workings are such that you just’re not more likely to really feel the distinction bodily.
Compliance can subsequently be an issue, as individuals are extra more likely to take one thing that has a noticeable impact. This may increasingly not occur with vitamin K2, however that definitely doesn’t imply it is not doing something.