A New Approach to Vitamin K2&D3 Combo Products: Part 2

A New Approach to Vitamin K2&D3 Combo Products: Part 2




As I like to do with most supplements, I try to find the highest safe intake among humans before recommending a maintenance dose of any nutrient. (Megadosing is usually a short term proposition, designed to get the storage levels of a given nutrient up to par when one is treating ailments.) So, when I recommend 50,000 IU of vitamin A weekly this is because that is roughly what is in one large serving of cow liver. Similarly, recommending 2 to 4 mg of iodine daily is comparable to the daily intake of the Japanese.


The Japanese also have the highest intake of vitamin K2 in the world due to their consumption of natto, the food richest in K2 (the next highest food is gouda cheese). Natto, made from fermented soybeans, contains 150 mcg of K2 (MK7 form) per tablespoon.


Now, a serving of natto is roughly 100 grams (a little more than half a cup) and, according to a study on vitamin K done at the University of Maastricht (The Netherlands), that amount contains between 850 and 1000 mcg of K2.  (Source)              


The question now is how often do the Japanese consume natto, and thus ingest nearly 1,000 mcg of vitamin K2? This turned out to be a difficult answer to find outside of one source reporting that “millions of Japanese start each day with a breakfast of natto and rice”.


Another reference stated that, based on a study from 2021, roughly a quarter of the population eats it every two or three days, about 17% eat it daily, and 13% eat it once a week (the rest eating it less often or never).


Let’s look at a conservative view of Japanese intake, assuming that one had a serving of natto three times a week,  at 850 mcg per serving. That provides 2550 mcg which when divided by seven days equals 364 mcg daily. Which in the case of our product would mean taking 24 drops providing 360 mcg of K2 along with 6,000 IU of vitamin D3. But this is of course a highly personal choice. 


As a side note, in case you want to try using natto as a food source of K2, this food has many other nutritive benefits. It is supportive of gut health (being a femented food), and that 100 gram serving also contains almost 20 grams of protein, over 5 grams of fiber, roughly 200 mg of calcium, 9 mg of iron, 230 mcg of selenium, and 730 mg of potassium, while being low in carbohydrates. However, be wary when buying natto. In our local Japanese food stores, any natto I have found is made from soybeans that are not organic or NonGMO, and often contains MSG. (Also be aware that most Westerners find natto to be, well, disgusting.)


Bonus Round


Population studies have determined that Japanese women have less facial wrinkles and skin sagging than North American women of the same age, and one could attribute this to the fact that the two groups have a very different diet and lifestyle.


However, when Japanese women living in Tokyo were compared with other Asian women from Bangok and Shanghai, the Japanese women still proved to have less visible signs of aging. Even though all groups had very similar dietary and lifestyle factors, the one difference was only the Japanese women consumed natto.   (Source)


We have already established that collagen in bones is supported by vitamin K2, and of course we all know by now that collagen, and elastin, are two essential components of skin health as well. These two connective tissue elements provide skin with elasticity and firmness and they decline in the body as we age, allowing for wrinkling and sagging to occur.


While there are limited studies to confirm this thesis, it is known that skin cells release a substance called matrix-GLA protein which prevents calcification of elastin in the skin.


And, in one study that looked at a genetic disorder where premature aging occurs, it was determined that elastin is “calcified due to the lack of Vitamin K2 activated matrix-GLA protein. Vitamin K2 could help maintain youthful skin activating Matrix-GLA and in turn preventing calcification of elastin”.  (Source)




As I mentioned at the beginning, this article, and NutriStart, are not suggesting that you use more of our K&D combo than the label, and Health Canada, advises. Increasing doses of supplements should be only done after doing much research and/or consulting with a health professional. And, obviously certain health professionals (Naturopaths) are going to recommend higher doses than other health professionals (M.D.s), so, in part, it comes down to who and what you believe. 


Personally, I like to experiment on myself so, for example, since writing the newsletter on Megadosing Vitamin D, I have been taking 25,000 IU (5 days a week). I back that up with about 300 mcg of vitamin K2, and so far I am happy with the results (less brain fog, better mood). That was a personal choice done after examining the research. Also, as always, I recommend taking two days off of supplements every week. This serves as a safety valve: if we take in too much of a nutrient the body has a couple of days to use up the excess, important protection for those of us self-prescribing nutrients, often at levels above what is commonly recommended.

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