Best Vitamin D3 + K2 Supplements in 2026: Doctor-Reviewed Picks for Bone, Heart & Immune Health

Vitamin D3 and Vitamin K2 are two of the most commonly deficient—and misunderstood—nutrients today. While Vitamin D improves calcium absorption, Vitamin K2 determines where that calcium actually goes. That’s why taking Vitamin D without K2 may be incomplete—and in some cases counterproductive.

After reviewing ingredient quality, dosing accuracy, brand transparency, and real-world user feedback, the following are the best Vitamin D3 + K2 supplements available in 2026.

Most people in the United States consume less than recommended amounts of vitamin D. An analysis of data from the 2017–2018 National Health and Nutrition Examination Survey (NHANES) found that average daily vitamin D intakes from foods and beverages were 4.3 mcg in men, 3.8 mcg in women, and 5 mcg (200 IU) in children aged 2–19 years (NHANES 2017 - 2018).

Why Trust This Guide?

This review prioritizes supplements that meet four non-negotiable criteria:

• Uses Vitamin D3 (cholecalciferol) — not D2

• Includes Vitamin K2 as MK-7 (longer-acting, better absorbed)

• Manufactured under GMP or third-party tested standards

• Provides clear, effective dosing without unnecessary fillers

No products were included simply because they are popular—only those that meet these standards.

Quick Recommendation (If You Don’t Want to Read Everything)

• Best Overall: Sports Research Vitamin D3 + K2

• Best Budget / Maintenance Dose: NOW Foods D3 + K2

• Best High-Dose Capsule: Bronson Vitamin D3 + K2

• Best Liquid / Organic: Nusava D3 + K2 Drops

Scroll down for detailed reasons and what each is best for 👇

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 D Market Size

The Global Vitamin D Market size was worth US$ 1.26 billion in 2024 (R), and it is estimated to reach a valuation of US$ 1.7 billion by the end of 2028, expanding at an annual compound rate of 7.0% between 2025 and 2033.

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) (NIH, NIH).

What Is Vitamin K?

Vitamin K was discovered in 1929 as an essential nutrient for blood coagulation (blood clotting).

The initial discovery was reported in a German scientific journal, where it was called “Koagulationsvitamin” — which is where the “K” comes from (Source).

There are two main forms of vitamin K:

• Vitamin K1 (phylloquinone): Found in plant foods like leafy greens.
• Vitamin K2 (menaquinone): Found in animal foods and fermented foods (Source).

Vitamin K2 can be further divided into several different subtypes, the most important ones being MK-4 and MK-7.

Related: Nutritional Synergies of Vitamin D, K2 and Magnesium

Best Vitamin D3 and K2 Supplements (2026)

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. Sports Research Vitamin D3 + K2 

Check Price on Amazon

Best Overall

This is the most balanced and consistently well-reviewed D3 + K2 supplement available today.

NEW SOFTGEL SHELL: Sports Research Vitamin D3+K2 Plant-gel capsules now contain added Turmeric Root Powder in the outer softgel shell. This added plant-based yellow color helps protect the active ingredients inside against photo-degradation that may occur from exposure to UV light. While the appearance has changed, we can assure you that our Vitamin D3+K2 still contains the same great ingredients you know and love

Created in 1980, Sports Research is a privately-owned business born from a passion for fitness, wellness, and healing.

More than 100,000 customer reviews and a 4.8 out of 5 overall rating on Amazon. 

• Amazon Best Sellers Rank: #3 in Vitamin D Supplements.
• Contains 5000 IU (125mcg) of Vegan Vitamin D3 & 100 mcg of Vitamin K2 as MK-7. Suitable for those whose vitamin D level is deficient or insufficient.
• 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

Vitamin D supplements by Sports Research are available in various dose strengths:

• Vitamin D3 (1,000 IU softgels) > Check Price on Amazon
• Vitamin D3 (2,000 IU softgels) > Check Price on Amazon
• Vitamin D3 (5,000 IU softgels) > Check Price on Amazon
• Vitamin D3 (10,000 IU softgels) > Check Price on Amazon
• Vitamin D3 + K2 (5,000 IU softgels) > Check Price on Amazon
• Vitamin D3 + K2 (gummy) > Check Price on Amazon
• Vegan D3 (5,000 IU) > Check Price on Amazon

Why it stands out:

• 5,000 IU Vitamin D3 (ideal for optimization, not just maintenance)

• 100 mcg Vitamin K2 (MK-7) for proper calcium placement

• Plant-based softgel with oil for superior absorption

• Non-GMO, third-party tested

Best for:
Adults with low Vitamin D levels, limited sun exposure, or those looking for a single daily capsule with optimal dosing.

Related: Nutritional Synergies of Vitamin D, K2 and Magnesium

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

Around $10.51 > Check Price on Amazon

Best Budget & Long-Term Maintenance Option

NOW Foods is known for consistent manufacturing quality at an affordable price point.

Why people choose it:

• Lower daily dose suitable for maintenance

• Vegetarian capsules

• Trusted brand with decades of GMP compliance

Best for:
Beginners, younger adults, or those already within normal Vitamin D blood ranges.

More than 5,000 customer reviews and a 4.8 out of 5 overall rating on Amazon. As compared to the Sports Research Vitamin K2 and D3, the dose for vitamin D3 and K2 is lower.

• Amazon Best Sellers Rank: #19 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
• Dose strength 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.

3. Bronson Vitamin D3 Plus K2 (MK7) - Best Organic Vitamin D3 and K2 Supplement

Check Price on Amazon

Best High-Dose Capsule from a Trusted Brand

Bronson offers a straightforward, no-frills formula with clinically relevant dosing.

Highlights:

• 5,000 IU Vitamin D3

• 90 mcg Vitamin K2 (MK-7)

• Gluten-free, soy-free, vegetarian

Best for:
Those who want a high-dose option without liquid drops or complex blends.

• Amazon Best Sellers Rank: #7 in Vitamin D Supplements.
• 5,000 IU / 90 mcg (D3 / K2) per capsule
• 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.

Related: Best organic vitamin D3 and K2 supplements

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

Check Price on Amazon

• 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.  Live Conscious k2+d3 - Vitamin K2 MK7 with D3 Supplement by LiveWell | Bone & Heart Health Support - Patented Vitamin K & Vitamin D3 5000 IU

Check Price on Amazon

• 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

Check Price on Amazon

Best One-Capsule-Per-Day Convenience Pick

Zhou’s formula focuses on simplicity and adherence.

Why it works:

• Balanced high-dose D3 + MK-7

• One capsule daily

• GMP-certified production

Best for:
Busy users who value convenience and consistent daily compliance.

• 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.

7. Organic Vitamin D3 K2 Drops with MCT Oil Omega 3 (Nusava) - Best organic vitamin D3 and K2 supplement

Check Price on Amazon

Best Liquid & Organic Formula

Liquid supplements can outperform capsules for absorption—especially in older adults.

Why this one converts well:

• 5,000 IU D3 + 120 mcg K2

• Organic formulation

• MCT oil and omega-3 base for enhanced bioavailability

Best for:
People with absorption issues, pill fatigue, or preference for liquid dosing.

• Amazon Best Sellers Rank: #16 in Vitamin D Supplements.
• Amazon Customer Reviews: 4.4 out of 5 (more than 2,000 ratings).
• Certified Organic Vitamin D: Certified organic by Natural Food Certifiers, our multi vitamin D drops to enhance your health naturally. Our D3 K2 Supplement Organic Liquid has no fillers, is non-GMO & proudly USA-made - ensuring high-quality goodness. We've carefully curated & sourced our ingredients so that you can replace all your other D & K vitamin supplements with just one small Nusava bottle to take wherever you go.
• Liquid Vitamins Formulated for Maximum Potency: The Nusava K2 D3 Vitamin Supplement 5000 IU with MCT Oil and Omega 3 provides amazing support for a healthier mind and body. With 125mcg (5000 IU) of Vitamin D3, 120mcg of Vitamin K, 250mcg of Omega 3, and a blend of organic ingredients including MCT oil, flaxseed oil, and olive oil, the Nusava Vitamin D Liquid Drops for adults will definitely be your next holy grail supplement.
• Tons of Benefits in Every Drop: Nusava makes living healthier more convenient for people with demanding lifestyles, that's why we created 4-in-1 vitamins that have a multitude of benefits in every serving - ridding the need to purchase different bottles for different ingredients. With our potent blend, we make it convenient for you to get all the necessary mind, body, and heart-healthy nutrients for a stronger lifestyle.
• Liquid Vitamin D for Faster Absorption: Liquid vitamins take effect quickly and are more readily absorbed by the body, making it more potent than capsules or tablets. Moreover, most people (such as the young and elderly), tend to find it difficult to swallow pills. With our blend of liquid Omega 3, MCT Oil, and K2 D3 vitamin supplement, you don't have to worry about the difficulty of swallowing lots of capsules after every meal.
• Worry-Free Purchase: In addition to our promise of being a convenient multi vitamin D liquid, each purchase comes with a hassle-free refund or replacement policy. While we stand by the quality of our vitamin D supplements, your health and satisfaction will go above everything else. If in any case you experience issues with your liquid vitamin drops, simply reach out to us and we'll resolve it right away.

8. Go Nutrients Liquid Vitamin D3 with K2 (MK-7) - Best Liquid Vitamin D3 K2

Check Price on Amazon

Best Flexible-Dose Liquid

A good choice for users who want to adjust dosing gradually.

Best for: Sensitive users or those titrating Vitamin D levels slowly.

About this item:

• INCREASE OR NORMALIZE YOUR VITAMIN D LEVELS - Due to indoor lifestyles and limited D3 food sources, many people have a deficiency in the "sunshine" vitamin. Our product is an effective source for supplementing the body’s natural production.
• EASY TO TAKE LIQUID DROPS: No more swallowing pills! Our product is readily absorbed, digested, and assimilated by the body to assure optimal benefit. Most pills contain fillers, binders and/or other materials that take much longer to digest
• IMPROVE YOUR MOOD AND FEEL BETTER - Best known for building bones, this highly-potent vitamin d3 liquid can help improve your mood and overall body health. It's converted into a hormone that’s so important to brain function its receptors can be found throughout it.
• FORMULATED TO BE TASTELESS & HIGH POTENCY - Our supplement provides 1,000 IU of Vitamin D3 and 25 mcg of Vit K2 in 1 serving. It comes in black bottles to block UV sunlight which diminishes it's effectiveness. 

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 (Source).

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

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

How to Choose the Right One for You

If you’re unsure which option to pick, use this quick guide:

• Low energy, frequent illness, little sun exposure → Higher-dose D3 + K2

• Already supplementing Vitamin D → Lower-dose maintenance formula

• Digestive issues or pill intolerance → Liquid drops

• Long-term daily use → Brands with strong GMP compliance

Safety & Compliance Notes (Important)

• Do not combine multiple Vitamin D supplements unless advised.

• Vitamin K2 may interact with anticoagulants (e.g., warfarin).

• Blood testing (25-OH Vitamin D) is recommended for long-term high dosing.

• This article is for educational purposes and does not replace medical advice.

Final Recommendation

If you want one supplement that covers bone health, calcium metabolism, immune support, and cardiovascular safety, a properly dosed Vitamin D3 + K2 formula is one of the smartest additions to a daily routine.

👉 For most people, Sports Research D3 + K2 remains the best balance of quality, dosing, and value in 2026.

Frequently Asked Questions

What Does Vitamin D Do in Your Body?

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

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 (Source, 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 (Source, Source).

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

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 (U.S. Institute of Medicine 2011 Report).

However, many experts believe the guidelines are far too low (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 (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):

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.

What happens if you take vitamin d3 without k2?

Taking vitamin D3 without vitamin K2 may lead to an imbalance in calcium metabolism, potentially causing calcium to be deposited in the arteries instead of the bones, which could increase the risk of cardiovascular issues. It's generally recommended to take both vitamins together for optimal health benefits.

Related: 

Best Vitamin D3 Supplement

Best Vitamin D3, K2 and Magnesium Supplements

Vitamin D – The Remedy for Everything but Death?

Best Probiotic Supplements

Top Anti-Inflammatory Supplements

Best Zinc Supplements for Skin