If it isn’t clear from the title of my blog yet, I’ll make it clear.
I don’t normally recommend combo supplements of vitamin D3 with vitamin K (either K1 or K2). I get asked all the time why my brand of D3 doesn’t have K in it, and it would have been cheap and easy to put it in there but I chose not to, because of SO many reasons which I’ll discuss today, but mainly because the combination can increase risk of kidney stones (within a few years) and may contribute to coronary artery calcifications. It’s all because the two of those nutrients together add more calcium to your blood, and that’s not something you want!
Sky high doses of either D3 or K (or the combination of these in one supplement) can also lead to higher risk of fractures.
I know this article is going to frustrate some people, so I want it understood that I am not anti-vitamin K, in fact you can read about the virtues of K, especially for men, by CLICKING HERE to read my article entitled, Vitamin K2 – A Powerful Weapon Against Prostate Cancer.
But again, I don’t think it’s necessary to put into vitamin D formulas, and this is a controversial subject.
You may not realize this because makers of the combo Vitamin D3 with K2, do not typically mention this fact but D3/K2 combos aren’t tested on regular people. The tests were on a specific group of women: The clinical trials on the combo D3/K2 supplements were conducted on post-menopausal, who were not supported on anticoagulants, who may or may not have eaten their K through their diet. The trial was not on regular pre-menopausal women, or men for that matter. These were post-menopausal women who needed a little added calcium for a short period of time, so K was useful in that regard.
There isn’t a study to determine what is right for all of you. But current evidence suggests that post-menopausal women might benefit from both nutrients and I will elaborate on this later on. The trouble I have is that K isn’t testable, so how do you know you need it? How do you know when to stop it? When you pass a kidney stone?
So I recommend just the D, unless you are known to be deficient in K. In fact, I will tell you how you can get a free month’s supply of D in a couple mintues.
Both D and K are easy to get without supplementation by the way. For example, vitamin D can be obtained with a walk in some sunshine and fresh air, or just sitting on your rocking chair on your porch. The sunshine provokes vitamin D synthesis in your body. And vitamin K is found in delicious salads, vegetables and fruits.
When I say “vitamin K,” I really mean K1 and K2. Many people don’t realize that K refers to a group of nutrients, primarily K1 and K2. Supplement makers (but not myself) add either K1 or K2, or both to their brands of Vitamin D3. I do not do that. I’ll tell you more shortly, but right now I want to explain the differences between K1 and K2 real quick.
Vitamin K refers to several fat-soluble nutrients, similarly to saying “Vitamin E” which you probably also refers to a group of tocopherols and tocotrienols. For more understanding about Vitamin E, you can CLICK HERE to read my article on E called The Truth About Vitamin E.
Anyway, vitamin K1 comes from plants and leafy greens whereas K2 comes from eggs and animal-sources. With vitamin K, about 80 to 90% is consumed and derived from vegetables/leafy greens meaning it is K1 (not K2). It’s very easy to get if you eat pretty much any vegetable!
Vitamin K2 is produced by your own microflora, as in your ‘gut probiotics’ although not much is known about the absorption of vitamin K, or its transport out of the gut (and into the blood stream).
We do know natural K1 and K2 are readily available from your diet if you eat cheese, pork, chicken, eggs, egg yolk and fermented foods especially natto (which provides over 800 mcg vitamin K2 per serving). The point here is that you can eat it very easily, PLUS you make it 🙂
As for blood clotting, both K1 and K2 interfere with anticoagulant drugs. The difference is that the effect of K1 is relatively short, maybe a few hours, where as when you consume K2 rich foods (meats, cheese, eggs) the blood clotting can last for days and days! By that token, if a person is on anticoagulants, then experts would say to avoid vitamin K rich foods but they don’t say that the K2 runs more interference than K1. Everyone seems to be concerned about leafy greens, but the more insidious and long-acting of the two vitamin Ks would be the vitamin K2 rich foods because they would interact with the medication, negating the action for days, as opposed to hours with K1 rich foods.
Since we’re talking about interactions, you might be interested in my article, Avoid Dangerous Interactions When Taking Supplements.
As I stated at the outset, makers of supplements like Vitamin D sometimes include vitamin K in the formula, thereby providing both of these nutrients at the same time to an individual. Again, there is a tiny subset of people that might benefit in my humble opinion, but not the masses of people that take it. It may not be ideal for all of you who take the combo.
I’ll tell you why right now.
1. Vitamin K is beyond easy to get in your diet!
Essentially you can eat a lot of different foods and get more than an ample amount of K in your diet. I selected and downloaded the image at the top of my blog to show you the dietary sources of vitamin K.
For example, vitamin K rich foods include liver, broccoli, cabbage, Brussels sprouts, greens, endive, spinach, kale, lettuce, mustard greens, parsley, bananas, snap peas, edamame, Swiss chard, turnip greens, watercress, and for that matter, any other green leafy vegetable! Why do you need a supplement of this, that has potential to cause problems when you can simply eat a vegetable?
When you lay in the sunshine to get D, do you have to simultaneously eat a salad? ! No, of course not. You can get D, and all the goodness of D without having to have K too.
2. You make it.
Remember that you also manufacture K2 in your gut, using your own stash of intestinal microflora. There is some more detailed information about K in the database from the National Institute for Health. To read about vitamin K, CLICK HERE.
Do you feel like it’s a good move to take supplemental K when it can interact with so many things??? There are many interactions and many drugs that interfere with the effects of vitamin K, including antacids, blood thinners, drugs for cancer, seizures, cholesterol and even aspirin! You can’t just take a vitamin because someone tells you it’s ideal through promotional material, you really should make an informed choice to see if you need it, and again, there are no lab tests for this. Furthermore, your body naturally makes it so I’d just recommend you rely on your own body and your own system to make what it needs. The body is intelligent, it knows what to do.
3. It can cause excessive calcium (hypercalcemia)
Vitamin D and K both work together to raise calcium levels in the body, which may or may not be good for all of you. The trouble with too much calcium is it sneaks up on you and has been linked to atherosclerosis. Calcium, in excess, can contribute to heart arrhythmias, muscle pain or cramps, insomnia as well as agitation. It is what binds with oxalates to form kidney stones. Every have one of those, or know someone? They say the pain of that is worse than childbirth!
Taking combinations of D with K will cause more calcium to be retained in your body and again, this might not be right for you. So this is another reason I did not add it to my formula. It isn’t safe for all of you, and I write to millions of you at a time each week, and I don’t know how many of you have a history of heart disease, stones, muscle pain or sleeping problems. It felt safer to make a plain vitamin D, however I’m proud to say that I suspended the vitamin D in pure organic extra-virgin olive oil in softgels (unlike my competitors who use soy or vegetable or canola oil).
4. Vitamin K supplements cause blood to thicken.
This is the opposite of a blood thinner. Who wants super viscous blood? We’re all trying to thin our blood with baby aspirin, fish oils, aged garlic, ginger and ginkgo and even medications.
In fact, the addition of K with D3 supplements could be a contraindication for people on certain medications, specifically those on blood thinners (because it negates the action). Vitamin K is never recommended if you take anticoagulants. Millions of people take blood thinners in the US today! These are taken in the form of aspirin, or as prescription drugs like heparin or warfarin, and there are some herbal anti-coagulants too. These anticoagulants are often given parenterally during surgical procedures, and in the emergency room, as well as orally.
Remember, K is found in salads, greens, vegetables and eggs. You’re eating it on a daily basis. It’s not having an adverse effect if you eat it. The dose is natural as you might guess if you eat nutrients. It’s not a large dose like you might get in a supplement.
Imagine unknowingly getting too much K in your vitamin D supplement – a supplement you bought for say, cold and flu immunity! Vitamin D is basic, and used by millions of people for blood sugar management too. No one taking D for these purposes expects to have K raised, nor would they want it.
Imagine taking that combo pill (and not realizing the harm that the added K was interacting with one of your medications). You might have just bought yourself a trip to the ER.
Vitamin K (both K1 and K2) has the ability to block the actions of anticoagulants, which are given to patients with the intention to protect against stroke and heart attack. Here is just one ARTICLE from pubmed showing Vitamin K2 DOES impact anticoagulants:
This is another reason I did not include K in my brand of vitamin D (which by the way is suspended in organic extra-virgin olive oil). I don’t want to accidentally hurt someone. You simply don’t expect K to be in a D supplement. This makes reading the fine print imperative for you if you happen to be on multiple medications.
5. My vitamin D isn’t a bone formula.
Many of you are taking D for your bones, and the K helps transport the calcium into your bone. That’s all fine and good, but MOST people do not take D for bone-building effects. Most people take it for immunity, blood glucose, mood support for melancholy or Seasonal Affective Disorder.
Some people need additional D if they take a statin cholesterol drug because those medications (ie Mevacor, Lipitor) can reduce D levels making supplementation critical. FYI, this category of drugs can make you very tired, and feel weak due to their depletion of an ‘energy’ hormone. Please take 5 minutes to read, Statins are Drug Muggers of DHEA.
So if you’re taking D for any reason other than bone mineral density loss, you don’t really want to jack up your K levels, do you? The worst part is you can’t measure your K levels so you really don’t know until the hypercalcemia sneaks up on your muscles, heart, mood or arteries.
You don’t need the additional calcium either. It would have been easy and cheap for me to put K into my vitamin D formula but I leftist out on purpose because I made a D for everyone, it’s not necessarily for bone support. You can always add a stand-alone supplement of K if you feel strongly that you need it.
6. You Only Need D to Raise Blood Levels of D
Having added K1 or K2 doesn’t raise levels of D any faster. Some of you have taken a blood test for vitamin D and found out you’re deficient in it. So then you have to take high doses of D for a few months to build up your levels to physiological “normal” status. So when you take high doses of D like this, you should NOT be taking high doses of K, hence combination products would not be my recommendation for those of you taking a short-term high dose D supplement.
7. Vitamin K is so easy to get!
We’ve kind of covered this but K is easy to get! Why would you take a lab-created form of it when you can put lettuce on your burger, or have a salad? Or eat some veggies? I believe in natural forms of nutrients and vitamins. We get D from sunshine, and we get K from our diet – very easily in fact!
D is a little harder because not all of us are sun-worshippers, and some of us have liver/kidney compromise so even the sunshine-derived forms of D don’t convert to the metabolically active hormonal form. My point is that supplementing with D makes total sense for some of you. But supplementing with D plus K doesn’t. Maybe if you have osteoporosis or osteopenia, then I can see that working out well, but for the majority of people, it is not necessary, and may produce adverse interactions and consequences due to the higher calcium levels precipitating out as stones.
8. K deficiencies are extremely rare.
When a doctor measures your blood test, they only evaluate vitamin D status, not K status.
With nutrients, balance is everything. There’s a risk to taking supplemental Vitamin K when you haven’t been evaluated for that and found to be deficient. Most people do not need to supplement with K because it’s in practically every popular food people eat, such as eggs, chicken, salads, vegetables, kale, cheese, popular fermented foods, and more. True deficiencies of K1 or K2 are extraordinarily rare.
The recommendations are as follows: Women above 19 years old should consume 90 micrograms (mcg) each day, and men should have 120 mcg. To put this in perspective, one cup of broccoli gives you 220 mcg, one cup of coleslaw provides 160 mcg, kiwifruit provides 63 mcg and sautéed spinach gives you 889 mcg! There are hundreds of foods that offer a substantial amount of vitamin K, so putting in a supplement doesn’t make sense to me at all, unless a company wants to market their “Vitamin D plus K” as a “superior” form, or if they are targeting bone health and assuming that you don’t take an anti-coagulant, and you don’t eat any fruits or vegetables either.
I’m being totally transparent with you and telling you it would have been super easy (and economical) for me to add some K to my D formula. But I chose not to because it’s unnecessary and potentially harmful to people if they take certain medications.
But good marketing by the makers have caused some people to feel like they need K, and that the sunshine vitamin all by itself is completely useless. So if you are in this category, I’d make sure because you can’t test your levels of K, only D. So ask a qualified holistic practitioner if it’s right for your situation, and how you can tell if you’re pulling one side of the spider web. I would recommend that you get a serum calcium level to check for hypercalcemia before taking products with added K, and I’d monitor calcium levels every six months or sooner if you develop cardiac or muscle symptoms. Just my two cents from working in long term care facilities for many years. Also, the parathyroid (PTH) hormone needs to be measured too. These things do have to be monitored. You can’t just pop a pill every day and not think about these, or adverse effects can occur in the future, and you’d never know it.
One more thing, vitamin D raises calcium levels, and this could cause a relative deficiency of magnesium, so an RBC mag should be ordered periodically too.
I’M NOT NEGATING THE VALUE OF VITAMIN K – I’M SAYING THAT I DON’T AGREE WITH COMBO SUPPLEMENTS OF D3 PLUS K BECAUSE OF MANY POTENTIAL INTERACTIONS AND INCREASED RISK OF HYPERCALCEMIA AND SURPRISE SIDE EFFECTS. IT’S EASY TO CONSUME IT FROM THE DIET.
How is the D measured? And how is K measured?
Just FYI, vitamin K2 administration in an animal model stimulated intestinal calcium absorption by increasing serum 1,25(OH)2D level. That’s the active form of vitamin D, not the storage form which is 25 D. Many doctors are still ordering the wrong type of D test. It should be 25-hydroxyvitamin D.
The higher the 1,25 D level, the lower the 25 D levels might be. You simply don’t know unless you measure both in the same blood draw. You could have both levels measured and see both levels simulatenously. Both markers of D have to be measured in my professional opinion. There is an important distinction between the 1,25 D levels that are controlled by your PTH, and 25 D levels which could be more indicative of a deficiency. Let me quote directly from aafp.org:
Many practitioners become confused when ordering a vitamin D test. Because 1,25-dihydroxyvitamin D is the active form of vitamin D, many practitioners think that measuring 1,25-dihydroxyvitamin D is an accurate means to estimate vitamin D stores and test for vitamin D deficiency, which is incorrect.
Current Endocrine Society guidelines recommend screening for vitamin D deficiency in individuals at risk for deficiency. Serum levels of 1,25-dihyroxyvitamin D have little or no relationship to vitamin D stores but rather are regulated primarily by parathyroid hormone levels, which in turn are regulated by calcium and/or vitamin D. In vitamin D deficiency, 1,25-dihydroxyvitamin D levels go up, not down.
Unregulated production of 1,25-dihydroxyvitamin D (i.e., sarcoidosis, granulomatous diseases) is an uncommon cause of hypercalcemia; this should be suspected if blood calcium levels are high and parathyroid hormone levels are low and confirmed by measurement of 1,25-dihydroxyvitamin D. The enzyme that activates vitamin D is produced in the kidney, so blood levels of 1,25-dihydroxyvitamin D are sometimes of interest in patients on dialysis or with end-stage kidney disease. There are few other circumstances, if any, where 1,25-dihydroxyvitamin D testing would be helpful. Serum 25-hydroxyvitamin D levels may be overused, but when trying to assess vitamin D stores or diagnose vitamin D deficiency (or toxicity), 25-hydroxyvitamin D is the correct test.
As for testing your levels of vitamin K, this isn’t easily done. When people excessive bleeding or experience easy bruising, the doctor orders a PT test (prothrombin). At that time they may be given a vitamin K shot which causes the blood to thicken (clot) which helps stop the easy bruising/bleeding. You can see that we’re dealing with serious stuff here, right? Bleeding internally and bruising and everything related to that impacts blood flow to your brain, heart and vital organs. You don’t want to take K in your supplements unless you need it. It’s not one of those vitamins to pop indiscriminately and see what happens!
I think the bigger question for most people is whether or not your dietary supplement should contain the two nutrients in one dose. For example, should you be supplementing with vitamin D all by itself, or K all by itself… or both together. The brands that are available today vary, some have K1 some have K2, some have both K1 and K2.
The addition of K to a D formula doesn’t cost very much more for the maker to do it. I looked into it because I’m a supplement maker myself. It’s a slight increase, very very inexpensive to add to a vitamin D formula. Again, I’ve looked into this very thing because I thought for a micro-second to offer this combo supplement like my competitors do! I have received so many questions about why I don’t offer it.
For sure, it’s a profitable way for makers to introduce this new and improved sexier version of D3 that is “stronger now with added K.”
The marketing is what is expensive because the ads and promotional material have to now convince you (well, not YOU specifically but people) that K is necessary to integrate the D into your bones, or into your heart, and brain… and they have to convince you that if you don’t get this NEW special combo pill that now contains K2 along with D… then you’re somehow going to suffer! It can be convincing, and quite scary.
It can become charged too, as people have very strong opinions about what’s right for them.
But what is right for one, isn’t right for all. There is a place for it, for a small group of people.
I feel like there is a subset of post-menopausal women who have bone loss in their scans, who may benefit from the combination of D3/K2 for short-term (a few months), provided they do NOT have a history of stones, or arrhythmias or heart disease… and also provided they’re not taking calcium supplements too (because it could cause hypercalcemia which leads to hardening of the arteries, atherosclerosis), and ALSO provided they’re not on anticoagulant thereapy (because it will interact) and ALSO they are not getting it from their diet because they’re not eating salads, broccoli, spinach or any other vegetable or leafy green! Phew!
I’d say if this mirrors you, and you are in that THAT specific scenario, then a combo D3/K2 could be safe and advised for you.
But do you see how ridiculous it is?! We’re talking about less than 0.01% of the population. For that matter, you don’t even need D. You could get D3 from the sunshine for free if you wanted to also, LOL! The issue with that though, is you have to convert the D3 to a body-ready hormone, and some people cannot physiologically due that due to liver/kidney compromise and so D3 supplementation becomes necessary for them. Plus, vitamin D is lab testable… we can test your labs and see what you need, and if you need it at all! So it’s intelligent to restore what is lost in that case.
It’s different with K, you can’t test for it, you MAKE it, plus you can eat it easily!
Real Quick – a note about Vitamin D3 sulfate
Vitamin D3 and Vitamin D3 sulfate are each beneficial in their own way. For example, regular D3 is fabulous at transporting calcium throughout your body, whereas the sulfated form of D doesn’t work for calcium transport. That said, it’s the sulfated form that offers protection to DNA and cancer. It provides immune support and helps with heart healthy. It also supports mood, making it the form that is best for depression. Your body knows how to convert the D vitamin that you take to the sulfated form.
Suzy Cohen, has been a licensed pharmacist for over 30 years and believes the best approach to chronic illness is a combination of natural medicine and conventional. She founded her own dietary supplement company specializing in custom-formulas, some of which have patents. With a special focus on functional medicine, thyroid health and drug nutrient depletion, Suzy is the author of several related books including Thyroid Healthy, Drug Muggers, Diabetes Without Drugs, and a nationally syndicated column.