Best Vitamin D3 with K2 Supplements 2021: Benefits, Reviews and Prices

In recent weeks and months, several publications and studies have suggested that maintaining adequate levels of vitamin D would seem potentially beneficial in fighting the COVID-19 infection. How do you know that your vitamin D level is adequate? Most people in the United States consume less than recommended amounts of vitamin D. An analysis of data from the 2015–2016 National Health and Nutrition Examination Survey (NHANES) found that average daily vitamin D intakes from foods and beverages were 5.1 mcg (204 IU) in men, 4.2 mcg (168 IU) in women, and 4.9 mcg (196 IU) in children aged 2–19 years (NHANES).

best vitamin D3 and K2 supplement

What Is Vitamin D?

Vitamin D is a fat-soluble vitamin, meaning that it dissolves in fats and oils and can be stored in your body for a long time.

Vitamin D is important to the body in many ways. It helps the body absorb calcium from food and supplements. Muscles need it to move, for example, nerves need it to carry messages between the brain and every body part, and the immune system needs vitamin D to fight off invading bacteria and viruses. Together with calcium, vitamin D also helps protect older adults from osteoporosis. Vitamin D is found in cells throughout the body.

Vitamin D2 vs D3

There are two main dietary forms (NIH):
  • Vitamin D3 (cholecalciferol). Found in some animal foods, like fatty fish and egg yolks.
  • Vitamin D2 (ergocalciferol). Found in some plants, mushrooms, and yeasts.
Difference between vitamin D and D3? Of the two, D3 (cholecalciferol) seems to be almost twice as effective at increasing blood levels of vitamin D as D2 (ergocalciferol) (NIHNIH).

Best Vitamin D3 and K2 Supplement Brands in 2020 / 2021

We have done our research and shortlisted the best for you. The list is based on recommendations by third party organizations, online reviews and popularity on search results and forums.

Here are the best vitamin D3 and K2 supplements that you can buy today.

1. Now Foods Vitamin D3 & K2 (120 Veg Caps)


Around $10.51 > Check Price on Amazon

More than 3,000 customer reviews and a 4.7 out of 5 overall rating on Amazon. As compared to the Sports Research Vitamin K2 and D3, the dose of the vitamin D3 and K2 are lower.
  • Amazon Best Sellers Rank: #31 in Vitamin D Supplements.
  • 1,000 IU / 45 mcg (D3 / K2) per veg capsule
  • Also has 3 mg of vitamin C per veg capsule
  • Supports Bone Health Plus Cardiovascular Support
  • Non-GMO, Family Owned Since 1968
  • GMP Quality Assured
  • Dosage is suitable to be taken as maintenance or long term.
  • Capsules might be a bit large for some users.
Editor's Note: Most of the Top 10 Vitamin D supplements as listed on the Amazon Best Sellers have dosages that exceed the maximum recommended dose (in USA and UK) of Vitamin D of 4,000 IU. Some of the brands also come in multiple dosages or dosage forms. Do check the label before you purchase.

2. Sports Research Vitamin K2 + D3 with Organic Coconut Oil


  • Amazon Best Sellers Rank: #4 in Vitamin D Supplements.
  • Contains 5000 IU (125mcg) of Vegan Vitamin D3 & 100 mcg of Vitamin K2 as MK-7
  • Made with Vitashine D3 - a patent, plant based form of Vitamin D3 from Lichen and MenaQ7 - a patent form of MK7 from Chickpea
  • 100% Plant based - Vegan Certified & Non-Gmo Verified. Soy, Gluten, Gelatin & Carrageenan free
  • Formulated with Organic Coconut Oil - Note: Capsules may appear 'cloudy' due to the Coconut Oil
  • Suitable for those whose vitamin D level is deficient or insufficient.

3. Bronson Vitamin D3 Plus K2


  • Amazon Best Sellers Rank: #15 in Vitamin D Supplements.
  • The Perfect Pair: Vitamins K2 & D3 were simply meant to be together. Most people know the benefits of Vitamin D, but many don’t realize that Vitamin D NEEDS Vitamin K2 to maximize it’s benefits.
  • Strong Bones & Healthy Heart: This formula not only promotes the proper absorption of calcium with D3, but the correct distribution to your bones where you need it most.
  • Superior Quality Vegetarian Capsules: Laboratory tested, NON-GMO, GLUTEN FREE, & SOY FREE. All Bronson products are tested in our state-of-the-art facility in New York.
  • Trusted Since 1960: The pioneers of Bronson Vitamins were a group of pharmacists who witnessed the benefits of vitamins and mineral supplementation firsthand with their patients. Bronson Vitamins have been consistently mentioned by top medical professionals since our inception in 1960.
  • Suitable for those whose vitamin D level is deficient or insufficient.

4. Vitamin D3 5000IU Plus K2, 2 in 1 Formula, Vitamin D3 Liquid with Vitamin K2, 300 Soft-Gels, Immune Vitamin Complex, Support Your Heart, Teeth, Joint Health and Immune Function, No GMO


  • Amazon Best Sellers Rank: #22 in Vitamin D Supplements.
  • Micro Ingredients Vitamin D3 Plus Vitamin K2 (Vitamin D3 K2), 300 Softgels.
  • Our Formulation, Vitamin D3 and K2 was Created to Work with your Calcium Intake to Support Bone Health and Promote Healthy Arteries.
  • Immune Vitamins Complex, Vitamin D3 for Kids and Vitamin D3 for Adults, Support your Joint Ability, Cardiovascular Function, Teeth Health and Immune System.
  • No GMOs, No Preservatives, No Artificial Colors, No Flavors, No Soy and No Gluten
  • 3rd Party Lab Tested for Purity and Safety.
  • Suitable for those whose vitamin D level is deficient or insufficient.

5. Vitamin K2 MK7 with D3 Supplement by LiveWell | Bone & Heart Health Support - Patented Vitamin K & Vitamin D3 5000 IU - 60 Capsules



  • Contains 5000 IU (125 mcg) of Vitamin D3 & 100 mcg of Vitamin K2 
  • Immune Booster: These two ingredients work together to strengthen your immunity. D3 plays a key role in activating an immune response to seek out foreign threats from invading your system.
  • Bone Health Support: Many people already know the benefits of vitamin D, including bone health and immune system support, but vitamin D needs K2 in order to be most effective, especially when fighting a vitamin D deficiency.
  • Boosts Healthy Blood Circulation: By ensuring that calcium gets where it needs to go, K2 promotes a cleaner overall circulatory system, as the calcium is better able to get where it needs to go.
  • Heart Healthy Formula: By fighting against the “hardening of arteries” due to calcification, this formula is a great way to promote heart health.
  • Vitamin K2 MK-7 type, which research has shown to be best suited to achieve healthy bones and improved heart health. [clinicaltrials.gov].
  • Suitable for those whose vitamin D level is deficient or insufficient.

6. Zhou Nutrition D3 And K2


  • Amazon Best Sellers Rank: #20 in Vitamin D Supplements.
  • At Zhou Nutrition, we take pride in providing just the right amount of high-quality ingredients for maximum results- no more, no less.The synergistic K2 + D3 is no exception. Just one small, easy-to-swallow veggie capsule per day provides 5000 iu of D3 and 90 mcg of K2 as MK-7, helping you support strong bones and a healthy cardiovascular and immune system.
  • Vitamins K2 & D3 were simply meant to be together. Most people know the benefits of Vitamin D (maintaining strong bones, immune system support, healthy muscle function, etc.), but many don’t realize that Vitamin D NEEDS Vitamin K2 to maximize it’s benefits. 
  • STRONG BONES- Vitamin D3 (termed the ‘sunshine vitamin') is the same biologically active form of Vitamin D you get from the sun’s UVB rays. With this complex, you’ll get the benefits without the burn. D3 helps your body absorb the all-important calcium, and Vitamin K2 (as MK-7, the form of K2 with the highest bioavailability) directs the calcium to your bones instead of your joints and arteries, where too much calcium could be problematic.
  • HEALTHY HEART - If you’ve heard the term “hardening of the arteries”, it’s referring to calcification. Calcification occurs when calcium has been absorbed by the body, but deposited in arteries instead of bones. This formula not only promotes the proper absorption of calcium with D3, but the correct distribution to your bones where you need it most.
  • At Zhou, we use only the highest-quality ingredients in a facility following GMP (good manufacturing practices). Plus, we test everything at our lab in Utah, so you can be confident that you're fueling your body with the very best.
  • During the summer months products may arrive warm but Amazon stores and ships products in accordance with manufacturers' recommendations, when provided.

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Frequently Asked Questions

What Does Vitamin D Do in Your Body?

Vitamin D needs to undergo two conversion steps to become active (SourceSource).

First, it is converted to calcidiol, or 25(OH)D, in your liver. This is the storage form of the vitamin.

Second, it is converted to calcitriol, or 1,25(OH)2D, mostly in your kidneys. This is the active, steroid-hormone form of vitamin D.



Calcitriol interacts with the vitamin D receptor (VDR), which is found in almost every single cell in your body (Trusted SourceTrusted Source).

When the active form of vitamin D binds to this receptor, it turns genes on or off, leading to changes in your cells. This is similar to how most other steroid hormones work (Trusted SourceTrusted Source).

Vitamin D affects various cells related to bone health. For example, it promotes the absorption of calcium and phosphorus from your gut (Trusted Source).

But scientists have recently discovered that it also plays roles in other areas of health, such as immune function and protection against cancer (Source).

Vitamin D3 supplements appear to be more effective at raising vitamin D levels than D2 supplements. 

Vitamin D ensures that your blood levels of calcium are high enough to meet your body’s demands. However, vitamin D does not fully control where the calcium in your body ends up. That’s where vitamin K steps in. Vitamin K2 supplements have been proven to be more effective than vitamin K1. That's why most of the top vitamin D supplement brands do combine their vitamin D3 with K2.

Signs and Symptoms of Vitamin D Deficiency

Vitamin D deficiency is one of the most common nutrient deficiencies.

Some people are at a greater risk than others. In the United States, 41.6% of the total population is deficient, although minorities fare worse — 82.1% and 69.2% of blacks and Hispanics are deficient, respectively (Trusted Source).

Additionally, older adults are at a much greater risk of being deficient (Trusted Source).

Those who have certain diseases are also very likely to be deficient. One study showed that 96% of people who had experienced heart attacks were low in vitamin D (Trusted Source).

Overall, vitamin D deficiency is a silent epidemic. The symptoms are usually subtle and may take years or decades to surface.

The most well-known symptom of vitamin D deficiency is rickets, a bone disease common in children in developing countries.

Rickets has been mostly eliminated from Western countries because of the fortification of some foods with vitamin D (Trusted Source).

Deficiency is also linked to osteoporosis, reduced mineral density, and increased risk of falls and fractures in older adults.

What’s more, studies indicate that people with low vitamin D levels have a much greater risk of heart disease, diabetes (types 1 and 2), cancer, dementia, and autoimmune diseases like multiple sclerosis (Trusted Source).

Finally, vitamin D deficiency is linked to a reduced life expectancy (Trusted SourceTrusted SourceTrusted Source).

That said, it’s unclear whether deficiency contributes to these diseases or whether people with low levels are just more likely to get them.

Vitamin D3 and K2 Vitamin Supplement Benefits

Half of adults over 50 years of age have low bone mass. Bone health is a real concern as we get older. Fortunately, the pairing of vitamin D3 and K2 seems to improve bone health across the board.

A groundbreaking 2017 review compiled over 80 studies that show vitamin D3 and K2 together might be greater than the sum of their parts, when it comes to bone health.

This is likely because vitamin D gets the calcium into the blood, then vitamin K tells the calcium where it is most needed.

Taking vitamin D3 and K2 together actually promotes new bone growth. In 2019, researchers observed that vitamin D3 and K2 worked in tandem to form new osteoblasts, the cells that secrete osteocalcin, which is a biomarker for new bone growth.

You can further minimize your vitamin D requirement by making sure you’re also getting enough magnesium. Magnesium is required for the conversion of vitamin D into its active form and research has confirmed higher magnesium intake helps reduce your risk of vitamin D deficiency by activating more of it. 

Taking both magnesium and vitamin K2 can lower your vitamin D requirement.

Eggs (44 IU per egg), along with fortified foods including milk and some cereals are excellent sources. 

What is the Reference Daily Intake (RDI) for vitamin D?

How much vitamin D3 should I take? The RDI for vitamin D is as follows (NIH):
  • 400 IU (10 mcg): infants, 0–12 months
  • 600 IU (15 mcg): children and adults, 1–70 years old
  • 800 IU (20 mcg): older adults (seniors) and pregnant or breastfeeding women
Do take note that you can also get good amounts of vitamin D and other essential vitamins and minerals from a basic multivitamin and milk formula. Always inform your doctor on the kind of supplements that you are taking as your doctor might also prescribe supplements for you that might lead to overdosing or duplicates.

If you are taking a multivitamin, your D-vitamin needs may be covered, but be careful not to let the total exceed 4,000 IU or 100 mcg.

To maintain healthy levels, only 400 to 800 IU (15 to 20 mcg) of vitamin D is required daily, but, to boost low levels, higher doses, such as 2,000 IU daily, are used and are generally safe.

A group of researchers from the US, UK, Netherlands and New Zealand, said that the RDA of vitamin D should be increased to 2,000 IU and vitamin C to 200 mg in their review published in Nutrients 2020.

Vitamin D Dosage Recommendations

In the US, current guidelines suggest that consuming 400–800 IU (10–20 mcg) of vitamin D should meet the needs of 97–98% of all healthy people (Trusted Source).

However, many experts believe the guidelines are far too low (Trusted Source).

Your vitamin D needs depend on a variety of factors. These include your age, skin color, current blood vitamin D levels, location, sun exposure and more.

To reach blood levels linked to better health outcomes, many studies have shown that you need to consume more vitamin D than the guidelines recommend (Trusted Source, Trusted Source, Trusted Source).

For instance, an analysis of five studies examined the link between vitamin D blood levels and colorectal cancer (Trusted Source).

Scientists found that people with the highest blood levels of vitamin D (over 33 ng/ml or 82.4 nmol/l) had a 50% lower risk of colorectal cancer than people with the lowest levels of vitamin D (less than 12 ng/ml or 30 nmol/l).

Research also shows that consuming 1,000 IU (25 mcg) daily would help 50% of people reach a vitamin D blood level of 33 ng/ml (82.4 nmol/l). Consuming 2,000 IU (50 mcg) daily would help nearly everyone reach a blood level of 33 ng/ml (82.4 nmol/l) (Trusted Source, Trusted Source, Trusted Source).

According to Dr John Campbell:
  • Deficiency: Less than 20 ng/ml (50 nmol/L)
  • Insufficiency: 21 - 29 ng/ml (52 - 72 nmol/L)
  • Sufficiency: More than 30 ng/ml (75 nmol/L)
Another analysis of seventeen studies with over 300,000 people looked at the link between vitamin D intake and heart disease. Scientists found that taking 1,000 IU (25 mcg) of vitamin D daily reduced heart disease risk by 10% (Trusted Source).

Based on current research, it seems that consuming 1,000–4,000 IU (25–100 mcg) of vitamin D daily should be ideal for most people to reach healthy vitamin D blood levels.

However, don’t consume more than 4,000 IU of vitamin D without your doctor’s permission. It exceeds the safe upper limits of intake and is not linked to more health benefits (Trusted Source).

What Is the Best Form of Vitamin D to Take?

The best form of vitamin D to take is D3. It’s the form that is most closely related to the same vitamin the human body creates. And with natural sources being quite limited, it’s often best to take vitamin D3 supplements.

Best Vitamin D Supplement for Absorption?

Vitamin D is a fat-soluble vitamin, meaning that it does not dissolve in water and is absorbed best in your bloodstream when paired with high-fat foods.

For this reason, it’s recommended to take vitamin D supplements with a meal to enhance absorption.

According to one study in 17 people, taking vitamin D with the largest meal of the day increased vitamin D blood levels by about 50% after just 2–3 months (NIH).

In another study in 50 older adults, consuming vitamin D alongside a fat-heavy meal increased vitamin D blood levels by 32% after 12 hours compared to a fat-free meal (NIH).

Avocados, nuts, seeds, full-fat dairy products and eggs are nutritious sources of fat that help boost your vitamin D absorption.

What is the Best Vitamin D Foods?

Here is the vitamin D3 content of a few of the best food sources (NIH):
FoodAmount% RDI
Cod liver oil, 1 tablespoon (15 ml)1,360 IU / 34 mcg227%
Salmon, cooked, 3 ounces (85 grams)447 IU / 11 mcg75%
Tuna, canned in water, 3 ounces (85 grams)154 IU / 4 mcg26%
Beef liver, cooked, 3 ounces (85 grams)42 IU / 1 mcg7%
1 large whole egg (D is found in yolk)41 IU / 1 mcg7%
1 sardine, canned in oil, drained23 IU / 0.6 mcg4%
Although fatty fish like salmon, mackerel, swordfish, trout, tuna, and sardines are decent sources, you would have to eat them almost every day to get enough.

The only excellent dietary source of vitamin D is fish liver oil — such as cod liver oil — which contains upwards of two times the Reference Daily Intake (RDI) in a single tablespoon (15 ml).

Keep in mind that dairy products and cereals are often fortified with vitamin D (NIH).

Some rare mushrooms also harbor vitamin D, and egg yolks contain small amounts.

Vitamin D in COVID 19

In recent months, there's been an upshot of studies demonstrating the benefits of vitamin D against COVID-19. The evidence is so compelling, more than 100 doctors, scientists and leading authorities have signed an open letter calling for increased use of vitamin D in the fight against COVID-19.

Based on several publications and studies, vitamin D seems to be the “most promising” supplement for COVID-19 protection. Vitamin D deficiency is known to enhance a process known as the “cytokine storm”.

Trusted Source).

There are many vitamin D studies underway. You can review the status of these trials on clinicaltrials.gov. As of July 2021, more than 70 studies have been launched to investigate the benefits of vitamin D against COVID-19.

Two studies in France (C Annweiler, Nov 2020G Annweiler, Nov 2020), one in India (A Rastogi, Nov 2020) and one in Spain (M Castillo, Oct 2020) showed that Vitamin D supplementation seems to decrease the mortality rate, the severity of the disease, and the inflammatory markers' levels among the COVID-19 infected patients, leading to a better prognosis and increased survival.

The largest observational study to date, looked at data for 191,779 American patients who were tested for SARS-CoV-2 between March and June 2020 and had had their vitamin D tested sometime in the preceding 12 months.

Of those with a vitamin D level below 20 ng/ml (deficiency), 12.5% tested positive for SARS-CoV-2, compared to 8.1% of those who had a vitamin D level between 30 and 34 ng/ml (adequacy) and 5.9% of those who had an optimal vitamin D level of 55 ng/ml or higher.

Data from 14 observational studies — suggest that vitamin D blood levels are negatively correlated with the incidence and/or severity of COVID-19; meaning if your vitamin D level is high, your risk for COVID-19 is low and vice versa.

A study published in November 2020 from Singapore (CW Tan, Nutrition 2020), found that those who were started on a daily oral dose of vitamin D3 (1,000 IU), magnesium (150 mg) and vitamin B12 (500 mcg) within the first day of hospitalisation and continued up to 14 days were significantly less likely to require oxygen therapy and further intensive care.

Another study, published in JAMA (JAMA Netw Open - Sep 2020) found that persons who are likely to have deficient vitamin D levels at the time of COVID-19 testing were at substantially higher risk of testing positive for COVID-19 than were persons who were likely to have sufficient levels.

The same team above, has also published a preprint article: A study at the University of Chicago of over 4,000 patients that found that untreated vitamin D deficiency was associated with an increased risk for COVID-19 infection.

study of 20 European countries found a link between low levels of vitamin D and higher percentages of COVID-19 cases and mortality. 

Separately, more than 80% of 200 people hospitalized for COVID-19 in Spain were found to be deficient in vitamin D, according to a study published in October in the Journal of Clinical Endocrinology & Metabolism.


High Dosage Vitamin D COVID-19 Studies

In a study from Nature (Sci Rep, May 2021) to investigate the effects of daily high-dose supplementation (60,000 IUs) of vitamin D — for eight to 10 days, in addition to standard therapy, for COVID-19 patients deficient in vitamin D; Vitamin D levels increased significantly in the vitamin D group — from 16 ng/ml to 89 ng/ml — while inflammatory markers significantly decreased, without any side effects.

Two studies in France (C Annweiler, Nov 2020G Annweiler, Nov 2020), one in India (A Rastogi, Nov 2020) and one in Spain (M Castillo, Oct 2020) showed that Vitamin D supplementation seems to decrease the mortality rate, the severity of the disease, and the inflammatory markers' levels among the COVID-19 infected patients, leading to a better prognosis and increased survival.

Annweiler et al.: All residents in the nursing-home receive chronic vitamin D supplementation with regular maintenance boluses (single oral dose of 80,000 IU vitamin D3 every 2–3 months), without systematically performing serum control test as recommended in French nursing-homes due to the very high prevalence of hypovitaminosis D reaching 90–100 % in this population.

Rastogi et al.: Participants were randomised to receive daily 60 000 IU of cholecalciferol (oral nano-liquid droplets) for 7 days with therapeutic target 25(OH)D>50 ng/ml (intervention group) or placebo (control group).

Castillo et al.: Eligible patients were allocated at a 2 calcifediol:1 no calcifediol ratio through electronic randomization on the day of admission to take oral calcifediol (0.532 mg), or not. Patients in the calcifediol treatment group continued with oral calcifediol (0.266 mg) on day 3 and 7, and then weekly until discharge or ICU admission. Outcomes of effectiveness included rate of ICU admission and deaths. Do take note that 0.25 mg is equivalent to 10,000 IU.

Editor's NoteVitamin D Upper Limit is 4,000 IU per day. The above dosages of vitamin D are NOT your normal maintenance dosage and are done under medical supervision and clinical trial setting. Do not self-medicate at this dosage!

Vitamin D and COVID-19 Treatment Guidelines from NIH

According to the NIH recommendation (last updated April 21, 2021):

There are insufficient data to recommend either for or against the use of vitamin D for the prevention or treatment of COVID-19.

Vitamin D and Vaccine

When the immune system isn’t properly fuelled and is impaired, this can lead to poor vaccine responses. A review of nine studies – together involving 2,367 people – found that individuals deficient in vitamin D were less well protected against two strains of flu after having been vaccinated compared to those who had adequate vitamin D levels.

Read more: How to make COVID vaccines more effective?



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