Best Vitamin D3 and K2 Supplements

You and countless people around the world probably have at least one thing in common: a vitamin deficiency. In the United States alone, around 95% and 67% of the population fall short of the Estimated Average Requirements (EAR) for vitamins D and K, respectively.1

D and K are among the 13 essential vitamins — the body requires them to function properly. They play critical roles in immune health, heart health, and bone strength,2 3 and they’re complementary, with D3 and K2 having a synergistic relationship that enhances their health effects. Browse the supplement market for either vitamin and you’ll quickly find they’re often formulated in combination.

In this guide, we present the market’s current best vitamin D3 and K2 supplements for optimizing your overall health and also discuss the science that informed our selections. Check out our summary of recommendations below if you're in a hurry, or read through the sections that follow to explore all of the details.

Over the past two decades, Innerbody Research has helped tens of millions of readers make more informed decisions about staying healthy and living healthier lifestyles.

We’ve cumulatively spent over 300 hours researching vitamins D3 and K2 and the synergy between the two. We’ve researched evidence about the benefits that each vitamin provides and the average micronutritional needs of adults within various demographics. After exploring the vast D3/K2 marketplace and trying the most promising products ourselves, we can present to you a set of the very best options to consider alongside comprehensive perspective that balances clinical findings with personal experiences.

Additionally, like all health-related content on this website, this guide was thoroughly vetted by one or more members of our Medical Review Board for accuracy and will continue to be monitored for updates by our editorial team.

We rated the market’s best vitamin D3/K2 supplements based on:

• General effectiveness
• Safety
• Cost
• Ease of use

It’s these criteria that we feel are the most relevant to consumers seeking the benefits that D3 and K2 can provide.

Here’s how our recommendations measured up in each category.

General effectiveness

Winner: NOW Foods Vitamin D-3 & K-2

Effectiveness is a complex question when it concerns D3 and K2 supplements because optimal intakes depend on several factors, not least being one’s geographical environment.4 5 Our goal, then, was to identify the supplement that could accommodate the largest number of people. NOW Foods is that supplement. Here’s why:

• Its 25mcg dose of vitamin D3 equals 1,000 International Units (IU), which is the same as the “standard” oral dose set in a 2006 study on healthy vitamin D status.5
• Its 45mcg of vitamin K2 relative to its vitamin D3 is approximate to the ratio used in a 2011 German study.6 That’s important because sufficient vitamin K can prevent calcium buildup in the blood, a risk that comes with vitamin D supplementation.
• Its D3-and-K2-only formula, combined with its ingredient quantities, makes it simple to titrate doses to accommodate different health needs without elevating the risk for toxicity from other ingredients.

Our other recommendations are effective, too, except they cater better to narrower user populations. Innerbody Testosterone Support has a formulation geared specifically toward men, Codeage toward postmenopausal women, Metagenics toward people with vitamin D deficiency, and Sports Research toward vegans. We discuss each product’s considerable merits in its dedicated brand section later in this guide.

Safety

Winner: NOW Foods Vitamin D-3 & K-2

Each of the brands in this guide does a pretty good job of testing ingredients and finished products, either in-house or by a third party lab, so we focused on individual ingredient bills to determine our safety winner.

The winner is NOW Foods Vitamin D-3 & K-2. Even though we’d prefer the product to be tested outside of NOW’s in-house labs, we’re assured of its safety by its certifications:

• Intertek GMP Supplement Certification: Ensures uniformity in manufacturing and demonstrates “continuous improvements” in Good Manufacturing Practice standards
• Halal: Uses ingredients that are permissible for practicing Muslims to consume
• Triangle K Kosher: Uses ingredients permissible under strict Jewish dietary law

Also, because of its simple and moderately dosed formula, NOW Foods poses the least risk of vitamin D toxicity. Every one-capsule serving has 25mcg (1,000IU) of vitamin D3 and 45mcg of vitamin K2. The D3 dosage is 5mcg over the Recommended Daily Allowance (RDA) but well under the 100mcg Tolerable Upper Intake Limit (UL) for adults,7 while the K2 quantity represents around 38-50% of Adequate Intake (AI).8 Notwithstanding your dietary vitamin D intake and sun exposure, you’d need to take four times the label-recommended serving size before you came close to exceeding UL, and vitamin K doesn’t have a UL given its low potential for toxicity. At the same time, there’s no need to mind other ingredients that have their own ULs, so you have considerable wiggle room for safe titration.

You’ll find less wiggle room with our other recommendations, even the ones with simple formulations themselves. Sports Research, for instance, delivers 62.5-250mcg (2,500-10,000IU) of vitamin D3 per serving, and Metagenics has 125mcg (5,000IU) per serving, so either one can put you over the UL edge with just one or two softgels. With Codeage and Innerbody, you’ll need to account for ingredients like zinc, magnesium, and calcium, each of which has its own intake limit and side effects, so dosing becomes more complicated if you want to titrate up.

Though this is a simplified view — you’ll see later in our safety section just how nuanced dosing can get with D3 and K2 — it lays out the main idea that NOW Foods’ dosages offer you the flexibility you need to meet your D3 and K2 needs while minimizing potential dangers.

Cost

Winner: NOW Foods Vitamin D-3 & K-2

One bottle of NOW Foods Vitamin D-3 & K-2 provides 120 servings and costs just $14.99, or approximately $0.12 per serving. In terms of base and per-serving prices, none of the other recommendations in this guide offer anywhere near such a bargain. Even if you take a double serving every day, you end up paying a fraction of a cent less than you would with a single serving of the runner-up, Codeage, which costs $10-$15 more per bottle.

But there’s a caveat for people who need higher doses to correct a deficiency, for whom a cost-per-IU analysis might be the superior guiding metric. If that sounds like you, then the alternative cost winner is actually our choice for the best deficiency-correcting supplement, Metagenics. Every IU of Metatgenics costs around $0.00009, which is a few fractions of a cent lower than NOW ($0.00012).

Ease of use

Winner: Metagenics Vitamin D3 5000 + K

Usually, when we discuss a supplement’s ease of use, it comes down to two questions:

• How big is its serving size?
• How difficult is it to swallow?

With our top vitamin D3/K2 supplements, the first question was mostly moot because almost all of our recommendations have a serving size of just one capsule/softgel, and it doesn’t get any lower than that. Only Innerbody Testosterone Support breaks the mold with a four-capsule serving size.

As regards the second question, we could immediately determine the running was between Metagenics and Sports Research. These two products are softgels, whereas NOW Foods and Codeage are capsules, and softgels are generally easier to swallow owing to their malleable structure and smooth surface.9 We’re also talking about very small softgels. Both Metagenics and Sports Research measure just 1cm long and roughly 0.5cm wide, so they presented no difficulty in our testing when washed down with a gulp of water.

So, Metagenics and Sports Research are equally easy to swallow. Then, what advantage does one have over the other? It’s the packaging, believe it or not. Both products come well-sealed under a tabbed adhesive liner, but Sports Research’s seal was noticeably more difficult to pry off. It required so much force that the tab itself appeared at risk of tearing off from the seal. Only NOW Foods’ seal, whose tab actually did come off, was more difficult to undo.

Before we get into the science behind D3 and K2, check out this quick-reference chart comparing our top recommendations based on key deciding factors. The prices listed are for direct purchases. They exclude any shipping costs and are rounded to the nearest cent or dollar.

Vitamin D, in general, is an essential fat-soluble vitamin that can be produced from within the body (endogenously) and obtained from outside of the body (exogenously). Endogenous vitamin D is produced by exposure to sunlight, which converts a compound called 7-dehydrocholesterol into D3, whereas exogenous vitamin D comes from food or supplements.7

Vitamin D3 is one of the main forms in which vitamin D occurs. By taking a vitamin D3 supplement, you could potentially improve bone health, cognitive health, muscle strength, cancer risk, and mood disorders.21 22

The other big vitamin D is D2. As supplements, vitamins D2 and D3 differ in their:7

• Production: D2 is plant-based, whereas D3 normally derives from sheep wool. There are exceptions, like Sports Research’s VegedDELight D3 derived from lichen.
• Effect on blood serum levels: D3 raises blood serum levels more significantly and maintains them for longer.

How much vitamin D do you need?

For adults, the Recommended Daily Allowance (RDA) of vitamin D is 20mcg, or 800 International Units (IU), while the Tolerable Upper Intake Level (UL) is 100mcg, or 4,000IU. In other words, you should aim to have at least 20mcg of vitamin D per day, but no more than 100mcg. These limits relate to exogenous sources, as a significant portion of sunlight-activated vitamin D becomes nonactive or gives rise to non-vitamin D forms that limit D3 formation.7

Because the body stores fat-soluble vitamins in the liver and adipose tissue, you can feasibly take a larger-than-UL dose on an infrequent basis. For example, people who are severely vitamin D-deficient may need a higher daily dose — like 125mcg (5,000IU)10 — to correct their deficiency. Also, it isn’t uncommon to take an even higher dose of 1,250mcg (50,000IU) capsule just once per week.11

Of course, you should speak with a medical professional before embarking on a vitamin D regimen, whether it’s low-dose or high-dose.

On a general level, we get into the particulars and nuances of dosing, as well as the symptoms of toxicity, in a later section, “How safe are vitamin D3/K2 supplements?”

Causes and symptoms of vitamin D deficiency

Vitamin D deficiencies often result from lifestyle factors: not getting enough sunlight or not eating enough vitamin D-rich foods, such as fish, yogurt, and certain mushrooms.12 That being said, an individual’s vitamin D deficiency may also stem from factors outside of their control, such as:13

If you have a vitamin D deficiency, you may experience any or all of the following symptoms:19 13

• Muscle and/or bone pain
• Muscle weakness, especially in the upper arms or thighs
• Muscle spasms, twitches, tremors, or cramps
• Tingling in the hands or feet
• An increased tendency for broken bones
• Mood changes, including depression
• Gait changes, such as waddling
• Bowed legs (a classic symptom of rickets, which is usually due to prolonged vitamin D deficiency in childhood)20

The only surefire way to tell you’re vitamin D-deficient is to take a blood test for your vitamin D levels (e.g., the 25-hydroxy vitamin D test). There are at-home vitamin D tests you can self-administer. Otherwise, the test must be ordered by a medical practitioner.

Vitamins K and D are similar in that they are both fat-soluble, capable of being produced endogenously, and commonly obtainable through exogenous means. Both are also important for bone health, and vitamin K is especially critical for proper blood clotting.33

K2, specifically, is a category that encompasses multiple isoprenyl side chains called menaquinones (MK) — namely, MK-4 through MK-14. The other vitamin K is K1, also known as phylloquinone.8 Between K1 and K2, there are three main differences:

• Dietary sources: K1 derives primarily from leafy green vegetables like broccoli and spinach, whereas menaquinones are synthesized by bacteria, including those in the human gut, and are also found in animal products and fermented foods.8 23
• Absorption: The body absorbs K2 more slowly than it does K1. Therefore, K2 remains in the body longer and has more time to deliver health benefits.24
• Health benefits: Both forms of vitamin K are important for blood clotting, bone health, and heart health, but K2 may be more effective when it comes to the latter two. Not only does K2 complement both D3 and calcium to help strengthen bones,24 but also, as studies show, K2 can help clear out the calcification that contributes to coronary heart disease.25 26

How much vitamin K do you need?

Vitamin K doesn’t have an RDA or UL attached to it; rather, it has an Adequate Intake (AI) value. AI takes the place of RDA when there isn’t enough research to establish an RDA.

Among adults, the AI value for vitamin K differs between men and women:8

• Men: 120mcg
• Women (including pregnant and lactating): 90mcg

As far as dietary sources go, 1-2 servings of green vegetables should get you over the threshold, at least for K1. However, for K2, you’ll want to incorporate foods such as:27

• Fermented foods (sauerkraut, kefir, natto)
• Chicken breast and/or chicken liver
• Ground beef
• Salami
• Egg yolks
• Certain cheeses (e.g., gouda, blue cheese)

Use discretion, though, because some of those foods may pose health risks (e.g., cardiovascular risks with cheese and processed meats, as well as cancer risks with the latter)28 29 30 — which you can circumvent by taking a K2-inclusive supplement.

Causes and symptoms of vitamin K deficiency

Vitamin K deficiency, which occurs in 8-31% of otherwise healthy people, may arise in adults who:31

• Don’t eat enough K-rich foods: Vitamin K primarily comes from dietary sources, so it makes sense that overall K deficiency stems from a K-starved diet.
• Have certain gastrointestinal medical conditions: Diseases like celiac disease and inflammatory bowel disease can reduce the body’s ability to absorb fat. Because vitamin K is fat-soluble, such diseases consequently hinder K absorption.
• Take certain medications: Antibiotics can kill off the gut bacteria that synthesize vitamin K, and blood thinners can disrupt K metabolism.

It can also result from conditions during gestation or infancy. For example, exposure to maternal medications in the uterus can cause a baby to be born with a congenital deficiency, as can insufficient exposure to vitamin K during fetal development.32

Because vitamin K plays an integral role in blood clotting, the main symptom of K deficiency is excessive bleeding. Other symptoms may include:33

• Petechiae (visible pinpoint-size spots of bleeding under the skin)
• Bruising, often on the head
• Jaundiced or pale skin
• Vomiting
• Sleepiness
• Seizures
• Dark, sticky, and/or bloody stools

As with vitamin D, a K deficiency is diagnosed through testing. If you’re experiencing the above symptoms or have another reason to suspect that you’re deficient, please consult with a medical provider.

Vitamins D3 and K2 are pleiotropic nutrients with synergistic effects. Let’s break down what that means:

• Pleiotropic: capable of producing more than one effect
• Synergistic: capable of working together to increase the effect of any one component

In other words, D3 and K2 both impart numerous benefits in the body, and when taken together, they enhance each other’s benefits. Or, to quote the authors of a 2017 review in the International Journal of Endocrinology: “Current evidence supports the notion that joint supplementation of vitamins D and K might be more effective than the consumption of either alone for bone and cardiovascular health.”34

Here’s an analogy to help illustrate. Say that a person wants to lose weight. In addition to restricting their calorie intake, they can incorporate cardiovascular exercise and/or weight training. The cardio would burn calories, and the weight training could improve their body’s ability to use its calories more effectively toward weight loss. So, think of vitamin D3 as cardio and K2 as weight training, or vice versa. Combining them is a double-whammy that can maximize outcomes.

There’s also research to suggest that coadministering vitamin D with vitamin K can help avoid the adverse effects associated with high doses of the former.46 So the combination isn’t just more effective but also potentially safer.

Vitamin D3 and K2 supplements may be appropriate for people who want to improve their bone health, cardiovascular health, and muscle strength, as well as potentially their cognitive function, mood, and cancer risk. Given these health benefits, we’d say the best-suited user populations include:

• Postmenopausal women: Women are often at a higher risk for osteoporosis after menopause because of the attendant estrogen deficiency,35 but combined administration of D3 and K2 may help prevent osteoporotic onset by increasing bone mineral density.36
• Men with low testosterone: There appears to be a direct correlation between low vitamin D and low testosterone, and increasing your intake of the former can elevate the latter.67 That’s why vitamin D3 is central to most high-quality testosterone boosters, and you’ll want to supplement with D3 to correct symptoms such as low mood, low libido, and erectile dysfunction.68
• The aging and the elderly: Vitamin D deficiency is associated with both aging and loss of muscle strength,37 38 and muscle loss is associated with aging.39 Preventing a deficiency, then, may help slow muscular decline. Additionally, vitamin D has shown the potential to stimulate the clearance of plaques associated with cognitive decline (e.g., Alzheimer’s disease).40
• People who weight-train: For the same reason that vitamin D supplementation can attenuate age-related muscular decline, it can also benefit people of any age who wish to grow or maintain their muscle mass.
• People who want to stave off cognitive decline: We can point to vitamin D’s effects on preventing cognitive decline to promote vitamin D supplementation among non-elderly people who want to stay mentally sharp as they age.

Who should not take a vitamin D3/K2 supplement?

The list of populations who shouldn’t take a D3/K2 supplement (or should exercise caution before taking it) is relatively small. They include but aren’t necessarily limited to people who:41

• Already have high levels of vitamin D
• Have high levels of calcium, as vitamins D and K can increase calcium absorption
• Have a malabsorption disorder
• Take certain medications, such as antibiotics, warfarin, orlistat, and prescriptions for lowering cholesterol33
• Are pregnant, as the supplement may affect the developing fetus

Anyone who falls into one of the above categories, and even those who don’t, should speak with their doctor to ensure that a D3/K2 supplement is safe for them.

Vitamin D3/K2 supplements are generally safe for most people who aren’t in danger of oversupplementation. But people who already get sufficient exogenous vitamin D, such as those taking another D-inclusive supplement, may be at risk for vitamin D toxicity, which can lead to hypercalcemia.

Hypercalcemia is an overabundance of calcium in the blood. Vitamin D’s connection to hypercalcemia lies in the vitamin’s ability to increase calcium absorption. People with hypercalcemia may have symptoms such as nausea, vomiting, muscle weakness, cognitive and neuropathic difficulties (including depression), dehydration, and kidney stones. (The risk for kidney stones is likewise increased with moderate intakes of vitamin D but higher intakes of calcium.)7

Besides hypercalcemia, vitamin D toxicity can also cause weakness, nervousness, high blood pressure, and a loss of appetite.42

However, vitamin D toxicity is considered to be rare. It’s not enough just to take a large dose of a D3/K2 supplement and then, bam, you have toxicity. Rather, it depends on how elevated your vitamin D blood levels have become. To increase your blood levels high enough that it becomes toxic, you may need to consume several tens of thousands of IU every day for several months.43 That’s why people are able to take something like 1,250mcg (50,000IU) once a week and maintain safe vitamin D blood levels.11

So, is a high daily or weekly dose right for you? That’s a question that should be answered by a medical professional after they’ve administered a blood test.

Also, one last note on safety concerning complex formulas that also contain D3/K2. With those, you should keep an eye on the quantities of other ingredients used in the formulation. The D3 dosages may be safe, but those of things like calcium, zinc, and magnesium may not.

Best for most people and best budget pick

Per serving, NOW Foods Vitamin D-3 & K-2 has 25mcg of D3 and 45mcg of K2. While there appears to be no consensus about the ideal D3-to-K2 ratio, NOW Foods’ vitamin D content is important.

Earlier, we mentioned a study, published in 2005, that defined a “standard” dose of vitamin D as 1,000IU, which is equivalent to 25mcg. The researchers based their conclusion on various factors related to people’s average exposure to sunlight, so it was a question of “how much exogenous nutrient relative to endogenous production?”5

NOW Foods isn’t alone in delivering 25mcg of vitamin D3 per serving. Innerbody Testosterone Support has the same amount. The difference is that NOW Foods has a much simpler formulation that comprises D3 and K2 exclusively, and in a one-capsule serving size. Those qualities together make it much easier to adjust the dose to individual needs.

Moreover, NOW’s D-3 & K-2 supplement has undergone the company’s comprehensive in-house product testing and received Intertek GMP Supplement certification to assure customers of potency, purity, and adherence to Good Manufacturing Practice standards.44 We do wish this particular product were third-party tested — Innerbody, Codeage, and Sports Research are — but the combination of a simple formulation and certification convinced us it was the safest D3/K2 supplement for the largest possible population.

Pricing, subscriptions, and shipping

NOW Foods Vitamin D-3 & K-2 comes in a 120-capsule bottle for $14.99 (around $0.12 per label-recommended serving). There’s no subscribe-and-save program through NOW Foods directly, so if that’s a dealbreaker, you may want to look into a third-party retailer or marketplace that does autoshipped subscriptions. iHerb lets you save slightly more than Amazon thanks to 20% off your first sale and a standard 10% off subsequent purchases if you set it to autoship.

If you purchase directly from NOW, shipping is free on orders of at least $50 to the contiguous United States. Otherwise, standard shipping costs $6.95, which is the same as Codeage and not at all bad; in fact, among our recommendations, only Innerbody has a better shipping arrangement (free shipping on all U.S. orders).

Refund policy

NOW Foods’ refund policy applies only to products that:

• Were purchased directly from its website
• Are new and unopened

The only exceptions to these requirements are items that were wrongly shipped or damaged in transit.

In any case, you have 30 days from the purchase date to return your item for a full refund. The return window is the same as Innerbody’s and Codeage’s. In comparison, Sports Research has a 45-day return period and Metagenics has a 60-day period.

You, the customer, are responsible for the return shipping cost.

Best complex for men

Innerbody Testosterone Support is (as you might have guessed) a testosterone booster, and there’s actually quite a bit of overlap between target audiences for D3/K2 and testosterone supplements. Notably, in a 2018 study, researchers concluded that higher levels of vitamin D were “significantly associated with high values of total testosterone,” so there's a positive correlation with associated measures such as erectile function.45

Innerbody Testosterone Support provides the aforementioned “standard” 25mcg dose of D3 along with 75mcg of K2. It’s also a highly packed, well-formulated complex with way more helpful ingredients for men experiencing the symptoms of low testosterone. Here’s just some of what you’ll find in every four-capsule serving:

Pricing, subscriptions, and shipping

Innerbody Testosterone Support costs $78 as a one-time purchase, while a monthly subscription costs $66.30 — a 15% discount. Each bottle contains 30 servings, so it's $2.21-2.60 per serving.

Unlike our other recommendations, Innerbody offers bulk orders of three or six units, with additional per-bottle savings.

Subscription delivery intervals depend on how many bottles you purchase:

• One bottle: every 30 days
• Three bottles: every three months
• Six bottles: every six months

Shipping is free for U.S. orders. That’s for both one-time purchasers and subscribers. No other brand in this guide attaches free shipping to one-time purchases.

Innerbody doesn’t ship internationally at this time.

Refund policy

Innerbody has a 30-day money-back guarantee. You can use Testosterone Support and, if you don’t like it, get a refund for the original dollar amount as long as you initiate your return within the designated time frame. NOW Foods and Codeage have identical return windows but stricter return policies. For example, NOW doesn’t accept used products, and Codeage generally limits eligibility for its guarantee to one item per customer.

Best complex for postmenopausal women

Epidemiological studies show that around 50% of postmenopausal women over the age of 50 have osteoporosis.57 That’s because menopause causes a decrease in estrogen, which in turn leads to a weakening of the bones.58

Codeage Calcium Pro+ is our D3/K2 recommendation for postmenopausal women because it provides sensible dosages of the nutrients needed to counter estrogen-related osteoporosis, namely:

Pricing, subscriptions, and shipping

Codeage Calcium Pro+ costs $29.99 as a one-time purchase and $25.49 as a subscription. Each bottle has 120 servings. If you go with the label-recommended serving size of one capsule, the per-serving cost equals around $0.25 and $0.21, respectively. Only NOW Foods, our budget pick and overall winner, has a lower per-serving cost. However, if you need a double dose, you’ll need to multiply those values by two, bringing the per-serving costs roughly in line with Metagenics.

Subscribers have a relatively wide range of delivery intervals: 1-4 months.

Codeage offers free U.S. shipping on subscriptions and orders over $50. Non-subscriptions and orders below the threshold get $6.95 tacked on for shipping. So, Codeage’s shipping policy is almost identical to NOW Foods’; apart from the fact that Codeage has a direct subscription program, the one, very subtle difference is that NOW Food’s free-shipping threshold is $50, whereas Codeage’s threshold is over $50.

Refund policy

Codeage has a 30-day money-back guarantee with an important caveat: it applies to only one item per customer and household. So:

• If a single order contains multiple items, only one item is eligible for a refund.
• For multiple orders shipped to the same address (e.g., you and your partner make separate orders), only one item in one of the orders is eligible for a refund.
• Customers who previously received a refund from Codeage are no longer eligible to take advantage of the money-back guarantee.

What about bulk packs and bundles? For them, there’s a refund policy but no money-back guarantee. As long as you haven’t opened any of the items in the pack/bundle, you have 30 days to return the whole thing for a full refund. If you have opened one or more items in the pack/bundle, you can return only the unopened items for a partial refund.

Best D3/K2 supplement for correcting a deficiency

If you already have a vitamin D deficiency, you’re going to need more than the RDA dosage to get your blood levels up to an adequate measure. So said the researchers behind a 2014 study published in the Journal of the American Board of Family Physicians. What they recommended instead was a higher dose of 125mcg (5,000IU) until your levels normalize.10 That’s how much you’ll find in every one-softgel dose of Metagenics Vitamin D3 5000 + K. You also get 90mcg of K2, which is a clinically relevant dosage for cardiovascular outcomes.34

To be fair, Metagenics isn’t the only D3/K2 supplement that provides the 5,000IU needed to correct a deficiency, but it’s the best we’ve found that balances effectiveness with safety and cost. Compare it, for instance, with a similarly formulated D3/K2 supplement by Nature Made, a ubiquitous presence in grocery store supplement aisles across the United States. The Nature Made product has the same 125mcg of D3, plus 100mcg of K2, and it costs just $16.79 — so it’s clearly better, right? Not so fast, because Nature Made doesn’t subject its D3/K2 supplement to third-party testing (Metagenics does), and because it’s just 30 servings per bottle, the per-serving cost is actually higher than Metagenics.

We could also compare Metagenics to Sports Research D3 + K2 (one of our top recommendations) since the latter is also available in a 125mcg version. The reason we aren’t fully on board with Sports Research as the best corrector of D3 deficiency is that it’s made with vegan D3, and the current research on the topic is relatively sparse.

Though it isn’t all that important, at least one of our testers wanted to note: Metagenics smells really good. Opening the bottle, we were treated to scents of grapefruit and tangerine. No other brand in our guide has a remarkable fragrance.

Pricing, subscriptions, and shipping

A one-time purchase of Metagenics D3 5000 + K2 costs $28.25. A subscription is $26.84. Each container has 60 servings, so the per-serving costs are $0.47 and $0.45, respectively — not bad at all.

For subscribers, the default delivery interval is two months, which aligns with the bottle’s quantity. You can pause a delivery any time you want through your account settings.

Subscriptions ship for free, but otherwise, the standard shipping cost is $10. That’s the highest on our list.

Refund policy

Metagenics has the best refund policy among our recommendations: a 60-day satisfaction guarantee. Also, it applies to both direct purchases and purchases made through authorized resellers.

Unlike Codeage, Metagenics is pretty easygoing about its policy caveats. At the most, the company will want to verify your information and proof of purchase before it moves forward with issuing a refund.

Best vegan D3/K2 supplement

Supplemental D3 usually comes from sheep’s wool, which isn’t suitable for a strict vegan lifestyle. Fortunately, recent years have seen the advent of D3 derived from plant-based sources such as lichen, which is the source of the cholecalciferol used in Sports Research D3 + K2.

Sports Research’s product is available in three strengths: one with 62.5mcg of D3 per serving, another with 125mcg, and the last with 250mcg. All three varieties have 100mcg of K2 as well.

You’ll notice that one of the dosage options is similar to Metagenics D3 5000 + K, our recommendation for correcting a vitamin D deficiency. But as we said in our discussion of Metagenics, the current research on vegan D3 isn’t robust enough for us to conclude that it’s as effective as the stuff you get from sheep’s wool.

There’s some research, though — enough that we can confidently recommend Sports Research to people committed to a strict vegan lifestyle. For example, a 2023 study published in the International Journal of Biomedical Investigation determined that lichen-based vitamin D may be “absorbed at a higher rate than regular vitamin D.”64 The study had limitations, though, particularly its very small sample size of just ten subjects. It was also written by a researcher who appears to be affiliated with the brand that manufactured the vitamin D used in the study.

For now, we feel that Sports Research is the strongest bet for vegans looking for a boost to their vitamin D3. If vegan D3 is less bioavailable than the non-vegan version, then the higher-than-standard doses found in the formulation may help offset lesser absorption.

Pricing, subscriptions, and shipping

Sports Research D3 + K2 varies in price depending on the bottle size, as well as the purchase option. Here’s the breakdown (per-serving costs rounded up to the nearest cent)

You see that aside from the 30-capsule bottle, Sports Research beats out Metagenics in per-serving costs, making it the third-most affordable option on our list — behind NOW Foods and Codeage.

Subscriptions ship out every 30, 60, or 90 days. They also ship for free, as do orders over $50. Non-subscription orders below the threshold get a flat-rate $7.50 tacked on for standard shipping.

No international shipping is available at this time.

Refund policy

Sports Research has a 45-day satisfaction guarantee for its supplements. The guarantee is valid only once per product, but that’s better than Codeage’s once-per-customer-and-household policy. Also, it does not apply to Sports Research products purchased through third parties, and you’re the one responsible for return shipping costs.