Link between Osteoporosis, Vitamin D and Vitamin K2

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Vitamin D is known in some circles as the wonder supplement, even touted right now as eliminating the risk of ICU admission due to COVID-19. But I’m not going to touch that one!
 
On a much more “well studied” level, vitamin D has been linked to reducing the risk of heart attacks, strokes, deaths related to heart disease, cancer, immune system function, brain function and bone health. 
 
Yup… it is kind of a wonder drug.
 
Today, though, I want to focus on bone health. Specifically, on the critical role of vitamin K2 and its inseparable relationship with vitamin D when it comes to bone health (and by default, cardio vascular disease). 
 
A bit of background…
 
Vitamin D
 
Of course, the best place to get vitamin D is through direct sunlight, as it’s made in our skin from UVB exposure to the sun. This leaves many of us vulnerable to low levels -- sunscreen, working inside, fear of skin cancer (understandable), our northern latitude, wearing clothes, etc. Hence many people are prone to vitamin D insufficiency*.
 
Other people that are prone to insufficiencies are:

  • older adults, whose skin isn’t as efficient at producing vitamin D

  • people with dark-coloured skin (which impairs vitamin D production)

  • people suffering from obesity, whose excess fat stores sequester the vitamin

  • compromised digestion causing inadequate absorption of vitamin D

You can obtain small quantities of vitamin D through food, such as fatty fish (salmon, mackerel, herring – all great sources of omega 3s btw), egg yolks and certain foods such as milk that’s been fortified with vitamin D), but often supplementing is recommended if a daily 5-30 min dose of sunlight is unavailable (yes, a big range - there are simply too many confounding factors)

Vitamins K1 and K2
Vitamin K1 (which we generally refer to as vitamin K) is considered the “dominant” K vitamin, and is readily available in leafy green vegetables, its main role being for blood clotting.
 
Vitamin K2 is a relatively recent discovery. It’s very different from K1, with completely different food sources and different roles.
 
Its primary role is moving calcium around to bones and teeth, and removing it from areas where we don’t want calcium. There are many subtypes of K2 – the most important ones to date being MK-4 (dominant in the brain) and MK-7 (dominant in our liver). MK-7 is the one that is synergistic with vitamin D (which I will simply refer to as K2 for purposes here).
 
The best food source for K2 is natto, a fermented soy. Liver is another good source, along with fermented dairy. Both gouda and brie cheese have modest amounts. Ultimately, it's not readily available in our diet.

Vitamin D's role in bone mineral density
Vitamin D is necessary for calcium absorption from food. It also controls the amount of calcium in our blood. Together with calcium, vitamin D protects older adults from osteoporosis. Without sufficient vitamin D, our bones can become thin, brittle and misshapen (1).
 
Calcium is an electrolyte. Aside from bone health, it’s used in a number of different ways in our body, including muscle contraction and neuron signaling in the brain. The amount of calcium in the blood is very controlled – so much so, that if there isn’t enough calcium in our blood, vitamin D will activate cells that break down our bones to draw calcium from our bones.
 
Yes, you heard me correctly… it will literally take calcium from our bones. Hence think decreased bone density over time, possibly leading to osteoporosis.  So make sure you get enough calcium in your diet! 

So where does Vitamin K2 come in?
Vitamin K2 controls where calcium goes in our body.  Specifically, it ensures that calcium is deposited into the hard tissues, where it belongs, like bone and cartilage.  Hence it’s critical for bone formation, bone mineralization, our skeleton and our teeth.
 
On the flip side, K2 ensures that calcium stays away from our soft tissues, such as our blood vessels and kidneys where it doesn’t belong. A build up of calcium in our kidneys leads to kidney stones, and in our blood vessels leads to atherosclerotic plaque (think heart attacks and strokes).
 
Net net…
Basically, vitamin D makes sure there is enough calcium in our blood (a reminder if it didn’t sink in the first or second time, it will take calcium from our bones if there isn’t enough in our blood), and then vitamin K2 directs the calcium to our bones and cartilage.

So… does that mean I have to supplement with both D and K2?
 Ugh – the million dollar question.
 
The consumption of a well balanced diet is key for primary prevention of any sort of disease.  In a perfect world, we want to get everything we need from nature and food.  Nutrients automatically work synergistically in our body.  Sadly, many of our foods have been deprived of essential nutrients based on soil depletion, forced ripening and travelling long distances.   
 
We also have to consider the state of our digestive system. If things aren’t working well, our small intestine won’t be effective at absorbing nutrients into our blood stream. As well, K2 is made by specific strains of our gut bacteria, and our digestion needs to be in tip top shape for this to happen...

  • Do you have a well balanced diet?

  • Are you eating 5-7 servings of a diverse number of vegetables a day?

  • Are you eating fermented foods? 

  • Are you getting enough sunlight? 

  • Is your digestive system working properly (ie – do you have any bloating, gas, constipation, diarrhea, general malaise, etc?  If so, things may be amiss)

Regarding supplementation, according to medical physicist Dr. Sarah Ballantyne, PhD , there is growing evidence that we want to supplement vitamin D and K2 together to support bone health and prevent osteoporosis, but there is not enough science showing exactly how much K2 to take relative to vitamin D.
 
She goes on to say studies show that if one is taking less than 800 IU/day (considered a low dose) of vitamin D, then they don’t’ need additional K2. If over 800 IU/day, many scientists feel it should be packaged with vitamin K, especially if one is high-dosing vitamin D (generally anything over 5000 IU).
 
First and foremost, it's important to get your vitamin D levels checked. If you have insufficient levels, then start supplementing, and get tested again.  
 
What levels should we be aiming for vitamin D?
In terms of “adequate” blood serum levels, the numbers vary. Some say that 20-30 ng/mL is a good level, but Sarah Ballantyne says 50-70 ng/mL. This wide range makes it challenging. Being aware that symptoms of a vitamin D deficiency can be low energy, feelings of anxiety/depression, feeling down in general or having a weak immune system could be tell tale signs. 
 
On the flip side, if one feels some of the above symptoms and starts supplementing, they might notice after a few months that they have more energy and are in a better mental state (assuming they are vitamin D deficient).
 
What about levels of K2?
K2 is much more difficult to measure. Most people don’t have signs of insufficiency, rather have to "hope" they are getting enough to reduce the risk of long term problems (osteoporosis and cardiovascular disease).  With K2, though, there is no upper limit of toxicity (unlike vitamin D), so there are no evident risks with supplementing.
 
Ultimately, it’s up to you. Lots more research needs to be done, but based on early studies, when it comes to bone health, especially in postmenopausal women, I, personally, want to make sure I’m covered. I take a supplement in the fall, winter and spring that has both vitamin D (1000 IU’s) and K2 (120 mcg)… no high dosing, just maintenance levels. 
 
In addition, I would recommend anyone now in menopause to ask for a bone density test (if you haven't had one) in order to get a baseline. Osteoporosis is NOT something we want to have as we age, as we know our estrogen levels decrease, and bone mineral density becomes an issue. 

On that note, weight bearing exercise is great prevention for osteoporosis as well, as is being outside in sunlight... GB Wellness Walk & Talk is the perfect opportunity to combine those elements with a nutritional reset!   Email me, check out my website or give me a call if you are interested in a free 20 minute consultation, and/or would like to take advantage of this amazing fall weather and go for a Walk and Talk.

Thanks for reading :)

gillian x
gillian@gbwellness.ca


 *Insufficiency vs deficiency – insufficiency means lower than adequate levels, but not low enough to cause symptoms (rather, negative effects happen over the long term); deficiency means levels are so low you are showing symptoms. For example, if you were deficient in K1, you could have nose bleeds, bleeding gums, heavy periods and/or bruise really easily. 

(1) https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/