When deciding on the best vitamin D supplements, we asked a team of testers—which included personal trainers and nutritionists—to test seven vitamin D supplements, then selected five products we felt were the best fit for demanding lifestyles. Additionally, we asked two registered dietitians (RD) to weigh in and had another RD review all of the supplements and the article itself to ensure accuracy.  

Whether your aim is to stay ahead at work, bolster your resilience, or simply maintain peak daily performance, we’ve got recommendations to help you ensure your vitamin D needs are covered. 

Why Trust Fortune

Our team of expert testers has tried hundreds of the most popular supplements on the market today, using our comprehensive supplement testing methodology to find the best products for all folks. 

Our Top Pick 

After testing various options, our team agreed that the best vitamin D supplement overall is 1st Phorm Liposomal Vitamin D3.

Best Vitamin D Supplements of 2026

• Best Vitamin D Supplement Overall: 1st Phorm Liposomal Vitamin D3
• Best Vitamin D Formula: Transparent Labs Vitamin D3 + K2
• Best Vitamin D K1 Supplement: Legion Vitamin D+K
• Best Vitamin D Capsules: Swolverine Vitamin D3
• Best Vitamin D Drops: AG1 Vitamin D3+K2
• Best Vitamin D K2 Supplement: Nutricost Vitamin K2 + Vitamin D3
• Best High Dose Vitamin D Supplement: Sports Research Vitamin D3

Best Vitamin D Comparison Table

Vitamin D	Vitamin D Per Serving	Form	Serving Size	Additional Ingredients
1st Phorm Liposomal Vitamin D3	5,000 IU	Liquid	4 ml	Vitamin K2, Vitamin A
Transparent Labs Vitamin D3 + K2	5,000 IU	Vegan softgels	1 softgel	Vitamin K2
Legion Vitamin D+K	2,000 IU	Capsules	1 capsule	Vitamin K1, vitamin K2
Swolverine Vitamin D3	10,000 IU	Softgels	1 softgel	Olive oil
AG1 Vitamin D3+K2	1,000 IU	Liquid drops	2 drops	Vitamin K2, MCT oil
Nutricost Vitamin K2 + Vitamin D3	5,000 IU	Softgels	1 softgel	Vitamin K2
Sports Research Vitamin D3	5,000 IU or 10,000 IU	Softgels	1 softgel	Coconut MCT oil

1st Phorm Liposomal Vitamin D3
Vitamin D Per Serving	5,000 IU
Form	Liquid
Serving Size	4 ml
Additional Ingredients	Vitamin K2, Vitamin A
Transparent Labs Vitamin D3 + K2
Vitamin D Per Serving	5,000 IU
Form	Vegan softgels
Serving Size	1 softgel
Additional Ingredients	Vitamin K2
Legion Vitamin D+K
Vitamin D Per Serving	2,000 IU
Form	Capsules
Serving Size	1 capsule
Additional Ingredients	Vitamin K1, vitamin K2
Swolverine Vitamin D3
Vitamin D Per Serving	10,000 IU
Form	Softgels
Serving Size	1 softgel
Additional Ingredients	Olive oil
AG1 Vitamin D3+K2
Vitamin D Per Serving	1,000 IU
Form	Liquid drops
Serving Size	2 drops
Additional Ingredients	Vitamin K2, MCT oil
Nutricost Vitamin K2 + Vitamin D3
Vitamin D Per Serving	5,000 IU
Form	Softgels
Serving Size	1 softgel
Additional Ingredients	Vitamin K2
Sports Research Vitamin D3
Vitamin D Per Serving	5,000 IU or 10,000 IU
Form	Softgels
Serving Size	1 softgel
Additional Ingredients	Coconut MCT oil

Best Vitamin D Supplement Overall: 1st Phorm Liposomal Vitamin D3

1st Phorm’s Liposomal Vitamin D3 stands out from the crowd because of its unique liposomal liquid formula. This allows users to quickly ingest and absorb the generous doses of vitamins D3, K2, and A for improved immune function, bone health, nutrient delivery, and overall wellness.

Our Tester’s Thoughts on 1st Phorm Liposomal Vitamin D3 

Our registered dietitian Mindy tested 1st Phorm’s Liposomal Vitamin D3 and rated her first impression a 3 out of 5 stars. “It has an athletic vibe, which fits with 1st Phorm’s overall branding,” she said. “The bottle is a convenient size, but the lid flips up rather than screwing off, which feels less secure to me for a liquid product.”

1st Phorm then earned its first perfect 5-star rating for how easy it was for Mindy to take. It was as simple and straightforward as pouring 4 milliliters and knocking it down the hatch straight from the spoon.

Overall, what impressed Mindy most was 1st Phorm’s comprehensive formula, which included vitamins D3, K2, and A. “Vitamin D3 and K2 work together to support bone health,” she said. “And the liposomal form is said to support the absorption of fat-soluble vitamin D3. For individuals who need additional vitamin D on top of other supplements or medications, the liquid form could be highly beneficial.”

What Testers Think Could Be Improved 

While Mindy found it easy to swallow the 4 milliliter dose, 1st Phorm did not include any measuring tools with the product. Something that might help someone measure a dose more accurately or while on the go might go a long way.

Additionally, Mindy rated the taste a 3 out of 5, commenting that she personally did not find it pleasant. “It tasted sweet and possibly a little bit citrusy,” she said, “although the package does not claim a specific flavor.”

Best Vitamin D Formula: Transparent Labs Vitamin D3 + K2

Transparent Labs Vitamin D3 + K2 is our pick as the best overall vitamin D formula because it pairs two highly effective nutrients, both essential to optimal health, in their most absorbable forms. With a vegan, allergen-free formula, rigorous third-party testing, and a dosage that meets the needs of those with above-average requirements, it offers a premium, science-driven solution. 

“The pairing of D3 with K2 matters because these two nutrients work together in a meaningful way: Vitamin D increases calcium absorption, and vitamin K2 directs that calcium into bones and teeth rather than allowing it to deposit in soft tissues or arterial walls,” according to Kristen Kuminski, RD, a registered dietitian nutritionist based in Buffalo, New York. 

Our Tester’s Thoughts on Transparent Labs Vitamin D3 + K2 

Pete tested this supplement and rated his first impression of the product a 5 out of 5. “This supplement comes in a white plastic bottle with a smooth screw-top lid that opens and closes easily,” he said. “The white label has navy and black lettering that’s easy to read. All key product details are clearly displayed, and the inclusion of the Informed Choice certification is shown on the front of the label.” 

He found the directions straightforward and easy to follow: “It says to take one softgel one to two times a day with a meal containing fats,” Pete said, rating the instructions a 5 out of 5. While the specification that the meal contain fats might seem inconvenient, vitamin D is a fat-soluble vitamin, which means it’s best absorbed with fats, so there’s a solid reason behind the instructions. Our tester also liked that Transparent Labs’ softgel capsules are small and easy to swallow, especially considering it’s only one capsule per serving.  

Our tester didn’t experience any taste when testing this supplement, nor did he have any side effects, rating it a 5 out of 5 in this category. Overall, Pete was pleased that Transparent Labs advises taking the softgel with a meal that contains dietary fat to support proper absorption.  

“This supplement is a solid option for anyone looking to boost or maintain higher vitamin D levels, especially if they don’t get a lot of sun exposure, such as during the winter months. I also like that the product is third-party tested, which adds an extra layer of trust and transparency,” he said. 

What Testers Think Could Be Improved 

Pete reported a very positive experience taking this supplement, reporting no significant drawbacks. Even the product’s online reviews, on the company website, are overwhelmingly positive with few users reporting negative experiences. 

Best Vitamin D K1 Supplement: Legion Vitamin D+K

We chose Legion Vitamin D+K as the vitamin D supplement with the best ingredients because of the presence of K1 and K2. Our tester Pete, a certified nutritionist, explained that “these vitamins all work in tandem to support overall health. Vitamin D helps your body absorb calcium, which supports bone health and immune function, while vitamin K2 plays an important role in directing the calcium into the bones.” As for vitamin K1, studies show it assists with blood clotting. 

Our Tester’s Thoughts on Legion Vitamin D+K 

All of these ingredients are powdered and stored in a clear capsule that Pete noted was of average size (about 1 inch in length and 1/2 a centimeter in diameter). The instructions say to take one capsule a day with food, and Pete noted that it had no taste and was easy to swallow. 

Pete ended up giving Legion Vitamin D+K a perfect score of 5 out of 5 for both first impression and instructions/ease of use. “It comes in a compact black plastic container with a screw-top lid that opens and closes easily,” he said. “The label features a black and light yellow design with clear, easy-to-read text, and the bottle’s small size makes it convenient for travel.” 

While Pete’s experience with Legion Vitamin D+K was a positive one, he clarified that he would have to get bloodwork done over a longer period of time to confirm any measurable changes in his vitamin D levels. But that’s the case with any supplement on this list. 

What Testers Think Could Be Improved 

Even though this product is affordable, its cost per serving is slightly more expensive than the other products we tested. Still, we consider this a minor drawback for an otherwise solid product. 

Best Vitamin D Capsules: Swolverine Vitamin D3

 We chose the Swolverine Vitamin D3 as the best vitamin D capsules because this supplement is a high-potency vitamin that doesn’t require multiple capsules to get the full dosage. This is a single softgel serving that contains 10,000 IU. We love that this option undergoes rigorous third-party testing and that Swolverine puts careful thought into the sourcing of ingredients and manufacturing of their health products.

Our Tester’s Thoughts on Swolverine Vitamin D3

Because Swolverine’s Vitamin D3 comes in a discrete and compact bottle that is small enough to bring along in a small bag or person, our tester Paige gave it a 5 out 5 for first impression. “The aesthetics of the packaging are very clean and appealing,” she said. “I like the ‘W’ on the Swolverine logo and it has a nice teal and white color scheme.”

During testing, Paige also noted that the single softgel is small and easy to swallow, giving it a 5 out of 5 for swallowability as well as flavor. “The pill does not have any obvious taste,” she said. “I appreciate that because there’s not supposed to be a flavor to a softgel capsule. There was no coating or weird aftertaste.”

What Testers Think Could Be Improved

One thing our tester pointed out is that this supplement is meant to be taken every three days, and that some people may find this schedule difficult to keep up with. She recommends a pill organizer to help keep on track with the unusual dosage schedule.

Best Vitamin D Drops: AG1 Vitamin D3+K2

We chose the AG1 Vitamin D3+K2 as the best liquid vitamin d supplement because this easy-to-take option delivers 1,000 IU of vitamin d and 100 mcg of vitamin k2 in each two-drop serving. This vitamin is made with MCT oil, and was made to support bone health and immune function. We also thinks it’s a great option for anyone who has difficulty swallowing pills, but wants to add a vitamin D supplement to their daily routine.

Our Tester’s Thoughts on AG1 Vitamin D3+K2

Our tester and registered dietitian Pete noted that this liquid supplement comes in a dark amber glass dropper bottle with an easy-to-open unscrew cap. He gave AG1’s Vitamin D3+K2 a 5 out of 5 for first impression, saying, “The bottle itself is nice and compact. It’s about an inch-and-a-half wide and three inches tall, so I’d consider it travel-friendly.”

During testing, Pete noted the instructions are clear, instructing users to take two drops daily, and rated it 5 out of 5 for ease of instructions. As far as flavor goes, he said it was flavorless, but gave it a rating of 3 out of 5 because of consistency. 

“It does have an oily consistency due to the d3 + k2 being mixed in MCT Oil,” Pete says. “The drops are so small you really don’t notice anything. It was super-easy to take. I just put two drops on my tongue in the morning after breakfast and swallowed.”

Pete had a good experience taking AG1’s Vitamin D3+K2 and appreciated the affordability of the supplement. He did state that he suggests having blood work done after taking the supplement for a while to be certain the dosage is appropriate for maintaining healthy Vitamin D levels.

Best Vitamin D3 K2 Supplement: Nutricost Vitamin K2 + Vitamin D3

Nutricost’s Vitamin K2 + Vitamin D3 is our pick for the best combination K2 and D3 supplement thanks to its clinically effective dosages of both nutrients, excellent value, and trusted third-party testing for safety and efficacy. By providing 5000 IU of D3 and 100 mcg of K2 (MK-7) in a single, easy-to-swallow daily softgel, it addresses two of the most crucial vitamins for bone density and cardiovascular function.  

Unlike the previous product, which included vitamin K1, this product’s formula includes vitamin K2. Kuminski said that while they sound similar, they’re actually quite different, explaining, “K1 is found in leafy greens and is primarily involved in blood clotting. K2, particularly the MK-7 form, is what influences calcium metabolism and works synergistically with D3. They’re related but functionally quite different, and K1 does not provide the same bone and vascular benefits that K2 does.” 

Our Tester’s Thoughts on Nutricost Vitamin K2 + Vitamin D3 

Kate tested this vitamin D supplement, rating her first impression of the product a 5 out of 5. “The bottle has typical Nutricost branding. It is very clearly labeled and easy to understand what the product is,” she said. It’s a regular twist-off bottle, so she found it super easy to open and close. “The bottle isn’t as small as some of the other vitamin D bottles I’ve tested, but it could still fit in a larger purse or backpack,” she said. 

She rated swallowability a 5 out of 5, saying: “These softgels are very tiny! They are smaller than penny. They were very easy to swallow, and since I only had to take one, I had no issues with it!” 

Our tester didn’t experience any side effects after taking this supplement. Overall, Kate thinks this is a great neutral product for someone who is looking to increase their vitamin D intake. “It’s cost efficient and reviewers didn’t seem to have many, if any, side effects from it,” she said. 

What Testers Think Could Be Improved 

Kate did notice a bit of a taste to these softgels, rating that factor a 3 out of 5. “You can really smell the softgels when you first open the bottle–they smell and taste a bit funky. It’s not overwhelming at all, especially since the softgels are so small,” she said. This didn’t bother Kate, but it could bother folks who are sensitive to taste and smell when taking a supplement.

Best High Dose Vitamin D Supplement: Sports Research Vitamin D3

Sports Research Vitamin D3 stands out as the best high-dose supplement due to its exceptional potency, ease of use, and quality assurance. Our tester tried the 5,000 IU softgel, which required just one pill per day, but the 10,000 IU version is identical in appearance and taste—still one softgel daily, making it a simple switch if a higher dose is needed. This supplement offers significantly more vitamin D than is recommended by the National Institutes of Health, which says the average adult needs 15 micrograms (or 600 IU) of vitamin D per day, with people over 70 years old needing slightly more. Besides the high dosage, we also appreciate the inclusion of organic coconut MCT oil for enhanced absorption, and the product is non-GMO and third-party verified. We recommend talking with your doctor before starting any supplement, but especially if you are considering a high potency supplement such as this one. 

Our Tester’s Thoughts on Sports Research Vitamin D3 

Kate tested this supplement, rating her first impression of the product a 5 out of 5. “The Sports Research branding is great: the black matte bottle with a flip top is appealing both visually and when opening the bottle,” she said. “It’s very easy to tell what the product is, and its clearly labeled in white font.” However, Kate noted that this is the largest bottle out of all the vitamin D she’s tested, and is not travel-friendly. 

Our tester rated the swallowability a 5 out of 5, praising how small the pill is. “It’s smaller than my pinky nail, which made it super easy to swallow. It is a softgel, which added to the comfort when taking it. It has a clear, yellowish tint to it and is striking against the black container, which I enjoy. You only need to take one softgel per day, so it is very easy to consume,” she said. 

Overall, Kate said she consider this a good product to take for a cost efficient and large dose of vitamin D. “Since it’s extra strength, it’s important to check with your doctor to see if this is the right dosage and product for you due to possible side effects,” Kate said. She loves that you get nearly a year’s supply in one bottle, 360 servings, for only $17.95. 

What Testers Think Could Be Improved 

Kate found the smell and taste to be slightly fishy but still rated it a 5 out of 5 in this category. “It tastes a bit sour when it sits on your tongue, but the taste quickly goes away once you swallow the softgel with water. I didn’t notice an aftertaste at all,” she said. 

What is a Vitamin D Supplement?

A vitamin D supplement is a product designed to help you meet your daily vitamin D needs, and is typically available in pill, capsule, powder, or liquid forms.  
 
“Vitamin D is a fat-soluble nutrient that functions more like a hormone than a traditional vitamin—it plays a role in calcium absorption, bone density, immune regulation, and mood,” Kuminski says. “Most people don’t get enough from sun exposure or food alone, so supplementation often makes sense, particularly for those in northern climates or who spend most of their time indoors.”  

Additionally, says Juliana Vocca, RD, founder and registered dietitian at Prime Women Nutrition, “Vitamin D does far more than support bones. While it’s essential for calcium and phosphorus absorption, it also acts as a hormone that helps regulate immune function, reduce inflammation, support nerve signaling, and maintain muscle strength.” 

Types of Vitamin D Supplements 

Vitamin D supplements come in two primary forms: vitamin D2 (ergocalciferol), derived from plants and fungi, and vitamin D3 (cholecalciferol), synthesized from animal sources or produced naturally in your skin by sunlight exposure.  
 
According to Kuminski, “When choosing a supplement, look for vitamin D3 (cholecalciferol) rather than D2—D3 is the form your body produces naturally and absorbs more efficiently.” 

How We Tested and Selected the Best Vitamin D Supplements

When choosing top vitamin D supplements, we collaborated closely with a registered dietitian to ensure our testing focused on safety, effectiveness, and clinical backing. Formulas selected provide at least 100 percent of the recommended daily value (RDV) for vitamin D, and each product avoids artificial sweeteners, colors, and unnecessary additives. 

Formula

Partnering with an RD strengthens our commitment to finding supplements with clinically supported dosages and thoughtful ingredient profiles. Specific to vitamin D, we select formulas that guarantee at least 100% RDV and steer clear of artificial ingredients.

Swallowability

We prepare each vitamin D product according to the manufacturer’s instructions and pay attention to how well the product dissolves, especially with powders. Avoiding gritty textures and off-putting taste ensures a better experience for routine daily use.

Third-Party Testing

Our team prioritizes products with third-party testing, such as NSF or USP certification. Third-party testing means the product has been independently analyzed for accuracy and purity, reducing the risk of contaminants or mislabeling. Since the FDA does not regulate most supplements as strictly as medications or foods, outside verification is crucial for consumer safety.

Value

In our evaluation process, we balance effectiveness, safety, ingredient quality, swallowability, and price to determine best-value vitamin D supplements. This approach ensures you get the most reliable product for your investment.

Vitamin D	Vitamin D amount	Price per serving
1st Phorm Liposomal Vitamin D3	5,000 IU	$1.40
Transparent Labs Vitamin D3 + K2	5,000 IU	$0.50
Legion Vitamin D+K	2,000 IU	$0.67
Swolverine Vitamin D3	10,000 IU	$0.33
AG1 Vitamin D3+K2	1,000 IU	$0.05
Nutricost Vitamin K2 + Vitamin D3	5,000 IU	$0.16
Sports Research Vitamin D3	5,000 IU or 10,000 IU	$0.05

1st Phorm Liposomal Vitamin D3
Vitamin D amount	5,000 IU
Price per serving	$1.40
Transparent Labs Vitamin D3 + K2
Vitamin D amount	5,000 IU
Price per serving	$0.50
Legion Vitamin D+K
Vitamin D amount	2,000 IU
Price per serving	$0.67
Swolverine Vitamin D3
Vitamin D amount	10,000 IU
Price per serving	$0.33
AG1 Vitamin D3+K2
Vitamin D amount	1,000 IU
Price per serving	$0.05
Nutricost Vitamin K2 + Vitamin D3
Vitamin D amount	5,000 IU
Price per serving	$0.16
Sports Research Vitamin D3
Vitamin D amount	5,000 IU or 10,000 IU
Price per serving	$0.05

Benefits of Vitamin D Supplements

Vitamin D can deliver several performance and health benefits, especially for people at risk of deficiency or those with increased needs due to high training loads: 

• May help reduce falls 
  May reduce risk of fractures in certain populations 
• May positively impact muscle strength 
• May be related to lower risk of preeclampsia 

How to Take Vitamin D Supplements

The optimal intake of vitamin D varies widely. General guidelines recommend 600 to 800 IU per day for most adults, but athletes, individuals with limited sun exposure, or those who are already deficient may need higher doses under medical supervision. 

Blood tests are the gold standard for assessing your vitamin D status—discuss supplementation with your doctor, particularly if you have specific health conditions or are on other medications. Common signs of vitamin D deficiency include fatigue, muscle weakness, bone pain, and frequent illness.

Can You Take Too Much Vitamin D?

Yes, taking too much vitamin D can be harmful. The tolerable upper intake level is typically set at 4,000 IU per day for adults, but toxicity is rare and usually associated with chronic intake of very high doses. Symptoms of vitamin D toxicity may include nausea, vomiting, weakness, and kidney problems. Always stick to dosing guidelines and talk with your doctor for personalized recommendations.

How to Find the Best Vitamin D Supplements for You

Vitamin D is essential for bone health, immune function, and muscle performance, but many people struggle to get enough of it just from sunlight or diet. Supplements can help bridge the gap, but the best option depends on your individual needs and goals. 

Vocca says, “When choosing a vitamin D supplement, form and absorption matter. Vitamin D3 is the most effective form because it matches what the body naturally produces. Since Vitamin D is fat soluble, softgels and liquid drops that contain fat tend to be better absorbed. Tablets and capsules need to be consumed with a meal containing fat.” 

Here are some other factors to consider: 

Your Fitness Goals 

Athletes and active individuals have unique vitamin D requirements compared to the general population. For example, runners may focus on bone strength for injury prevention, while strength athletes might emphasize muscle function and recovery. Knowing your specific fitness goals—whether it’s improving performance, reducing injury risk, or supporting recovery—can help guide your search for the right supplement. 

Ingredients 

Before purchasing a vitamin D supplement, review ingredient lists to check for allergens or additives that could interact with your dietary preferences or restrictions. You also want to make sure to avoid excessive or unclear dosing and products without third-party certification. 

Frequently asked questions

What is the most effective vitamin D to take?

Vitamin D3 (cholecalciferol) is generally considered the most effective form for raising and maintaining blood vitamin D levels.

What are the most common mistakes people make when taking vitamin D supplements?

Two of the most common mistakes people make when taking vitamin D supplements are: taking too little or too much without doing bloodwork first, and choosing poor-quality supplements without third-party testing.

Can vitamin D deficiency cause itchy rash?

Vitamin D deficiency is not a common cause of itchy rashes, but it can contribute to immune dysfunction, which may indirectly affect skin health. We recommend talking with your doctor if you are experiencing skin issues.