Surprising Vitamin K2 Deficiency Symptoms: Are You Low?


Western diets are now a health burden worldwide which is part of the reason that vitamin K2 deficiency is so common too.  With the trend for eating fast foods and junk foods globally on the rise, the trend for nutrition problems is following as well.

Even when you do eat a very healthy diet, it is next to impossible to get enough vitamin K2.

Vitamin K2 deficiency is newly discovered to be a problem in several regions of the world.  Read on to find out why this deficiency is harming both healthy adults and children. 

What is Vitamin K?

Vitamin K is a fat-soluble vitamin that plays an important role in proper blood clotting.  New functions of a specific form of vitamin called vitamin K2 are now being discovered.

Vitamin K2 (menaquinone) is distinguished from K1 by the presence of side chains in the structure, varying in length from 1 to 14 chains. The number indicates if it is menaquinone 4, menaquinone 7, menaquinone 9, etc.

The most commonly supplemented form of vitamin K2 is menaquinone-7.

Functions of vitamin K2 (not K1) include:

  • Calcium metabolism
  • Strength of bones
  • Artery health
  • Brain Health
  • Proper blood clotting

Although we don’t fully understand how vitamin K2 works in the brain, we know that vitamin K2 is related to eye and brain health too, according to recent research.

Deficiency of vitamin K2 at all ages increases the risk of disease.  These diseases include:

  • Bone fractures
  • Osteoporosis
  • Heart disease
  • Atherosclerosis

Vitamin K2 Deficiency is a Global Health Problem

Healthy children and adults have markedly low levels of a marker of vitamin K2 in the blood called undercarboxylated osteocalcin.

New research is showing that vitamin K2 deficiency is also a global problem for bone health.

Vitamin K2 Deficiency Increases Global Bone Fracture Risk

In Poland, children with low vitamin K status are at risk for a type of bone fracture called low-energy bone fracture.

Children aged 5-15 years old, admitted to the hospital with low-energy bone fractures,  had significantly lower vitamin K markers (carboxylated osteocalcin) than healthy children.

Findings from Europe recently showed that vitamin K status (undercarboxylated factor II) was low in 36% of patients with hip fractures in the elderly.

Intriguingly, after being held off food pre- and post-surgery, this marker of vitamin K deficiency increased to 64% of the group with hip fractures.

Vitamin K2 Deficiency Increases Global Heart Disease Risk

Research this year around the globe is showing how harmful low vitamin K deficiency is for heart health.

South Asians are at high risk for heart disease.  A study of 700 people from India, Pakistan, Bangladesh, Sri Lanka, Nepal, and Bhutan found new and important information about their heart risk.

Coronary artery calcification risk, which is highly related to vitamin K deficiency, increased cardiovascular disease risk over a 5-year period.  This increase was as high as white men, the group with the highest rates of heart disease.

This arterial calcification was a risk factor for cardiovascular disease in this group of South Asians, according to a publication in January 2019 of the Journal of the American Heart Association.

This study is part of the long-term Mediators of Atherosclerosis in South Asians Living in America (MASALA) study.

In a newly released study from China, vitamin K2 deficiency (dephospho-uncarboxylated matrix gla protein) increased the risk of heart mortality by almost 2 times.  This study was conducted in a patient population that is at high risk for heart disease: peritoneal dialysis patients.

Those with low vitamin K2 status also had more inflammation and had almost 3 times as high of a risk of heart events, such as myocardial infarction.

New research shows that K2 vitamins for colon health are also likely beneficial.

Why is there so much Vitamin K2 Deficiency?

The primary reason that vitamin K2 deficiency is so common is due to a lack of food sources.  Even the best diets fall short in vitamin K2.

As demonstrated in recent findings above, the withholding of food perioperatively also increases deficiency.  As you can see, deficiency can quickly develop, especially if people only rely on vitamin K1 food sources.

The RDA does not take into account our need for vitamin K2 for bone and artery health; it was only set to provide proper clotting.

Additionally, absorption of vitamin K1 is very poor in green leafy vegetables.

Experts used to think that vitamin K2 could be made in enough quantity in the digestive tract from bacteria.  The most recent evidence suggests otherwise.

A study was conducted where vitamin K was restricted in the diet, which resulted in vitamin K deficiency, so the digestive source of vitamin K2 is likely much less than previously thought.

Signs of Vitamin K Deficiency

Image of a human skeleton with wording vitamin K2 deficiency signs on a blue background by The Healthy RD
A skeleton indicating vitamin K2 deficiency

Signs of deficiency are the following.  Keep in mind, that none of these may be present when low in vitamin K2.  The signs may appear in the heart and bones.

  • Easy bruising
  • Excessive bleeding from wounds, punctures, and injection or surgical sites
  • Heavy menstrual periods
  • Bleeding from the gastrointestinal (GI) tract
  • Blood in the urine and/or stool
  • Increased prothrombin time (PT/INR)

Newborn vitamins get supplemental vitamin K.  This is because, while rare, bleeding is life-threatening in infants.

Now we know that vitamin K deficiency isn’t just a concern for infants.  The discovery of vitamin K2 and its roles has uncovered important areas of function and new risks of deficiency.

An increased suspicion of vitamin K deficiency occurs in the following situations. This includes people with malnutrition or poor food absorption, such as digestive disease.

People who are chronically ill are also at very high risk, including cancer or dialysis patients.

Medication-nutrient interactions can also rob the body of vitamin K2.  They include:

  • Anticonvulsants (carbamazepine, phenytoin and barbiturates)
  • Antituberculosis drugs (isoniazid, rifampicin),
  • Some antibiotics (cephalosporins)
  • Vitamin K antagonists (warfarin): INR vitamin interaction

Supplementing Vitamin K2

Keep in mind, that the last updates to the RDA for vitamin K were made BEFORE the important discoveries about vitamin K2.  Therefore the RDA isn’t reflective of our actual need for vitamin K2.

Cutting-edge research suggests that, for adults, supplements of vitamin K2 (MenaQ7) at 180 micrograms per day are an effective dose for improving bone and heart health.  For children, a dose of 45 micrograms per day is beneficial.

A nice review of vitamin K2 and the problem of food sources is on Chris Masterjohn’s website.

Can’t I just supplement Vitamin K1?

I wish this was the case, but we know that vitamin K1 isn’t even as good at clotting factors as vitamin K2.

It doesn’t absorb as well, and it doesn’t impact bone and heart health, unfortunately. You must get vitamin K2 if you want these benefits.

Here is a list of some great vitamin K2 patented supplements: (I will use some or all from the blog about best heart supplements).

Vitamin K2 Supplement Risks

Vitamin K2 is very safe.

If you are on blood-thinning medication, make sure to check with your doctor before adding in any supplements.

Related post: 11 Best Liposomal Vitamin C Supplements + Interesting Health Benefits

Vitamin K2 Deficiency Summary

Vitamin K2 deficiency, as measured in blood levels, increases the risk of heart disease mortality and death around the globe.

Bone health may suffer from low vitamin K2 globally as well.

Supplemental vitamin K2 may improve overall health and well-being and should be considered in all populations.

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