(Some things are just better together. While Vitamins D and K each provide their own benefits when taken separately, taking them together not only boosts these effects but creates new ones. As the saying goes, the sum is greater than its parts.
First, let’s talk about each vitamin separately.
Vitamin D has two forms. D2, known as the “sunshine vitamin,” is acquired from sunlight. Vitamin D3 is the from that we absorb best from food and supplementation.
While D2 is more well-known, D3 is more effective for oral supplementation, which is why it’s often used in scientific studies and supplements. It contributes to calcium absorption and plays a major role in bone health.
Vitamin K2 is a form of vitamin K. It can be produced by bacteria in your gut or found in animal products like fish and beef. K2 plays a significant role in the body’s blood clotting process and distribution of calcium.
In other words, D3 helps the body absorb calcium, while K2 helps direct calcium to where it’s needed.
When combined, Vitamin D3 and K2 complement and increase each other’s effectiveness.
Research shows that combining D3 and K2 might do the following:
A review of over 80 studies concluded that D3 and K2 were more successful at supporting bone health when used together than when used alone. This may be because D3 helps the body absorb calcium while K2 helps direct calcium to where it’s needed. This makes it a key combo for bone density and strong bones.
Vitamin D3 and K2 can work together to fight against cardiovascular disease and reduce inflammation. One study demonstrated that D2 and K2 could soften arteries when combined, reducing the risk of developing cardiovascular disease.
While vitamin C is all the rage for fighting colds, there actually isn’t good evidence that vitamin C supplementation supports the immune system and shortens colds. In contrast, recent compilations of research, like this 2017 meta-analysis, suggest that vitamin D supplementation can prevent acute respiratory infections (aka, a cold).
For immune function support, this is one of the few tried-and-true supplements out there.
An estimated 40% of Americans aren’t getting enough vitamin D each day. A deficiency of vitamin D can lead to muscle weakness, bone loss, osteoporosis, and bone fractures. Taking a Vitamin D3 supplement will, well, increase your vitamin D levels.
With all of this said, not all supplements are created equal. Today we wanted to share the best products on the market. Every product on our list is third-party tested and cGMP-approved.
*Note: We do have affiliate links throughout this article, which means we receive a commission if you purchase from any of our links. This supports our mission to bring complicated health and fitness info in an entertaining package. And it keeps us from putting up annoying things like banner ads. Those suck.
Best softgel: Transparent Labs
Best liquid drops: Double Wood
Best for children: Nordic Naturals Gummies
In turns of value, quality, and simplicity, look no further than Transparent Labs.
For just $20 bucks, you get 120 softgel capsules with a 5000 IU dose of vitamin D3 and 100 mcg of vitamin K2. The only other ingredient is the softgel capsule.
Transparent Labs is known for their, well, transparency. They have a certificate of analysis available for all of their supplements.
With just one capsule a day, you will be covering your bases. In fact, 5000 IU is enough even if you have a known vitamin D deficiency.
Double Wood’s D3 and K2 supplement offers high-quality ingredients for a good price. It’s also potent, with 5000 IU of vitamin D3 per serving. It also includes MCT Oil as a base, which might help with absorption. It is also U.S.-manufactured, vegan-friendly, gluten-free, soy-free, and non-GMO.
You may also notice this product has 200 mcg of vitamin k2, so you get a higher dose of k2 than most products.
With the liquid vitamin option, you can also vary your dose depending on your needs. You can take an ultra-high dose, or a lower dose.
Each bottle contains 30 servings. Double Wood offers a money-back guarantee.
This D3K2 product uses a liposomal delivery method to further increase bioavailability. Liposomes are lipids that are designed to protect ingredients as they go through the digestive tract, so more of it goes into your bloodstream.
Quicksilver’s Vitamin D3 + K2 liquid has 2500 IU of vitamin D per serving 90 mcg of vitamin d2.
It’s also a super pure and high-quality product. It’s tested free of allergens, tested gluten-free, non-GMO, and vegetarian-friendly. While a bit more expensive than the previous products on our list, with 100 servings and top-tier quality, you can’t go wrong.
Microingredient’s Vitamin D3 and K2 supplement provides up to 300 servings, making it a great bulk option. Its soft gel capsule contains sunflower seed in addition to vitamin D3 and K2. It has no added preservatives, artificial colors, gluten, or soy, making it a good choice for alternative diets.
Nordic Naturals has a pomegranate-flavored chewable gummy version. This is great for kids for a few reasons. First of all, kids generally prefer gummies. Look, I’m not parenting expert, but I remember being a kid and the flintstone vitamins were always the move.
Second, it has a smaller dose, 1000 IU, that’s perfect for people who need less.
With just 2 grams of sugar per gummy, even adults can get in on the fun with this product.
Thorne Research’s D and K2 supplement is small but mighty. Just one bottle contains 200 servings. Its solution is free of gluten, dairy, and soy. It can be taken on its own or added to any beverage or meal. In addition, Thorne Research offers a testing kit on its website to determine if a vitamin D supplement is necessary for you.
Sports Research offers a D3 and K2 supplement made with intentional, plant-based ingredients. It contains D3 derived from Lichen, K2 derived from chickpea, and virgin coconut oil all in a plant-based capsule. It’s manufactured in the USA and contains up to 60 servings.
MRM Nutrition’s Vegan Vitamin D3 and K2 is another supplement on our list made with plant-based ingredients. Its D3 is extracted from Lichen and is free of nuts, soy, gluten, and yeast. Each bottle contains 60 servings if taking 1 capsule per day (which is recommended, because it contains over 300% of your daily value).
NOW Foods Vitamin D-3 and K-2 offers a quality supplement at a great price point. Each capsule contains 1000 IU of vitamin D3 and 45 mcg of K2. This is on the lower side. Each bottle provides up to 120 servings. It comes in a vegetarian capsule.
You can have too much of a good thing, and vitamin D is no exception. Excess vitamin D, known as vitamin D toxicity, can cause high calcium levels that result in the following side effects:
Although vitamin D toxicity is pretty rare, it’s best to follow the recommended supplement guidelines to avoid these symptoms.
As always, the best way to determine if a D3 and K2 supplement is right for you is by consulting a healthcare professional. If you want stronger bones and improved cardiovascular health, a D3 and K2 supplement is worth the try.
Vitamin D is a fat-soluble vitamin. That means, it gets absorbed better in conjunction with other fats, rather than with water. Encasing it in a softgel, fat-based capsule, may support absorption. This is why vitamin D and omega-3 supplementation are popular as a combination; it may make the vitamin D more bioavailable.
While a multivitamin may have its place, for most people you pay for a ton of ingredients you don’t need (and just pee out), while not getting enough of what you do need. A better strategy is to figure out what you need. Vitamin D and K are common deficiencies, which is why it often makes more sense to pick up a supplement like this.
For a whole-food-based nutrition solution to cover your bases, we recommend looking into a greens powder supplement.
For supplements, vitamin D3, or cholecalciferol is the most studied form. It’s the form we absorb best as a dietary supplement. Per the research, it’s more effective at raising our vitamin D levels.
Vitamin K1 is what you’ll find in leafy green vegetables, while K2 is in fermented foods and animal products. Research has suggested that K2 (menaquinone-7) is more effective for bone health, and generally has higher absorption. That’s why it’s the most popular form in supplements.
Sure, you can, however most of us don’t. The reality is that modern lifestyles mean we’re inside a lot more, and practically speaking can’t get the vitamin D we need.
This is especially true during the winter, when we get less sun exposure.
Also, vitamin K does NOT come from the sun, and is also a common deficiency.
This is the shorthand for menaquinone-7, which is the chemical term for vitamin K2. They’re all synonyms.