Vitamin D3 Product Buyer’s Guide (updated May 2024)

Approved Science Vitamin D3+K2 Review



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Our research has shown that this manufacturer created a science-based formula that contains high-quality ingredients. We found that this product provides Vitamin D as D3 paired with Vitamin K as K2 MK-7 – which are the most effective vitamin forms for optimal health benefits. We also liked that it offers a 60-day money-back guarantee and comes with proper certification. 
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Why do we recommend Approved Science Vitamin D3+K2?

Main Benefits:

  • Helps improve vitamin deficiencies.
  • Assist the immune system and may reduce the risk of the flu or heart disease.
  • Improves Calcium absorption which aids bone building and maintenance.
  • Provides 5000 IU/125  mcg vitamin D as recommended by the Vitamin D Council.
  • Contains vitamin D3 which is natural, unlike D2.
  • Utilizes highly active vitamin K: 80% trans K2 Mk-7. 
  • Added BioPerine® optimizes nutrient absorption for more effective results.
  • The dosage is split between 2 pills for maintaining more even levels around the clock and allowing the flexibility for dosage adjustments.
  • No preservatives, artificial colorings, hormones, or unnecessary ingredients that may dilute the efficacy of the product.

In addition to the above points, we found many supportive consumer reviews from users who had experienced excellent results, some within as little as a week. Its daily suggested serving is the optimal potency as recommended by doctors for effectiveness and is supported by clinical research trials and studies. This manufacturer’s customer service is second to none; it provides excellent support and help. Furthermore, it offers an excellent money-back guarantee if customers are not satisfied with their results.


125 mcg of Vitamin D3 raises vitamin D levels more effectively than D2 and so we were pleased to see that Approved Science chose to use the right form of this vitamin. When our body synthesizes Vitamin D, it produces D3. You should be aware that when it comes to supplements, D2 is synthetic while D3 is generally animal-derived. Vitamin D supports immune system function, may reduce the risk of catching the flu, and regulates Phosphorus and Calcium absorption. Vitamin D helps prevent blood levels of Calcium from dropping which could cause the body to break down bones in order to release Calcium. However, excess Calcium in the blood can calcify the arteries and destroy their flexibility. Therefore, it’s important for Vitamin D supplements to also contain Vitamin K.

With 180mcg of Vitamin K2, this supplement helps the Calcium absorbed with the help of Vitamin D to be transported into the bones which helps to strengthen the bones. When it comes to Vitamin K, there are two forms. While most other supplements use MK-4, Approved Science Vitamin D3+K2 contains MK-7 which has been found to be more absorbable than MK-4. Furthermore, Vitamin K can be active (expressed as trans) or inactive (expressed as cis). Many companies do not share information about how active their Vitamin K is but Approved Science is transparent about the percentage of which their Vitamin K is active. At around 80% trans, this supplement has a very active and very absorbable Vitamin K for better results.

In addition to containing D3+K2, this product also contains BioPerine® which is a patented bioavailability enhancer that increases nutrient absorption and utilization. This ingredient helps you to get the best out of every pill. While many manufacturers don’t even consider this ingredient, we consider it to be a key factor in boosting the ranking of a supplement.

What we really like is that it is made by a company that consistently uses clinical studies as a benchmark for the dosage of all their health supplements. There is also a money-back guarantee which can be claimed by speaking to their customer service agents who are real people, not robots! There are so many products out there that do not fall within the realm of high standards, offering artificial alternatives and all sorts of extras inside their formulas. It is a relief to be able to recommend a company that manufactures such a unique, well-researched product.

To summarize, Approved Science Vitamin D3+K2 uses top-quality natural ingredients, provides awesome results, has a caring customer support team, and a great price. From what we saw, without a doubt, this is an extremely good product.

Quality Assurance

We were very happy to discover that Approved Science Vitamin D3+K2 is manufactured in an FDA-registered facility. Moreover, it is cGMP recognized and complies with the US Pharmacopeia’s standards for quality and purity. This suggests that Approved Science takes what it does very seriously, and strives to keep its products safe, natural, and effective – a mentality that we totally appreciate.

Over the last few years, we understand how consumers have grown skeptical of health supplements. This simply comes down to shady companies providing useless formulas that contain unrelated and useless ingredients or that add fillers or binders to their products. The active ingredients are what deliver results, so when you see a long list of inactive ingredients, you should be wary. Often, these ingredients are not pure, or have not been tested for quality and have no scientific validity as to why they have been included in the formulas. Not only is this irresponsible, but often quite dangerous since there is frequently a lack of understanding when it comes to these ingredients. Truth being, there is absolutely no reason why anything artificial should be added. Natural and pure is the best. If the ingredients are in their natural form, they are less likely to cause side effects or negative interactions.


Approved Science Vitamin D3+K2 comes at an affordable price with some excellent multiple purchase deals, allowing you to save big. Also, this company is staunchly against any auto-ship programs, as they can be nearly impossible to cancel. This policy further supports the evidence that Approved Science is a top quality company.

Orders are shipped within 24 hours, with the exclusion of any orders placed on weekends and holidays. They are wrapped and sent in discreet packaging, with no identifying marks on the outside, unlike other companies who often have embarrassing slogans or logos. Furthermore, this company provides a 60-day risk-free money-back guarantee. If you are not 100% happy with the results, you are able to return the product and receive a full refund. That shows Approved Science’s strong confidence in its product and we totally support that kind of guarantee.

In Conclusion

Approved Science Vitamin D3+K2 specifically contains the optimal blend of ingredients which are clinically proven to make an effective Vitamin D supplement. They are:

  • The recommended daily serving of 125mcg Vitamin D3.
  • 180mcg Vitamin K2 as MK-7 80% trans which is a clinically studied dosage and highly active compound.
  • BioPerine® for enhancing nutrient absorption and delivering faster results.
  • No unnecessary ingredients.

Of all the products that we reviewed, across all parameters, none compared to Approved Science Vitamin D3+K2. This product complies with the high standards of the US Pharmacopeia, undergoes third-party testing, and is backed by comprehensive customer reviews that give us a great indication of how the product really works. If you are looking for a top-quality formula backed by research and scientific data that is an effective, long-term solution to improve immunity, strengthen bones, and reduce the risk of heart diseases, you would be hard pressed to find anything better than Approved Science Vitamin D3+K2.

Approved Science Vitamin D3+K2
Dr. Mercola Vitamins D3 & K2
Designs For Health Vitamin D Supreme
Bioinnovations Pharmacal D3+K2
Contains 5000 IU (125 mcg) Vitamin D3 for improving deficiency
Contains Vitamin K as MK-7 which is more bioactive than MK-4
Contains 180 mcg K2 to effectively direct Calcium into the bones
Transparent about K2 activity percentage
Contains BioPerine® for enhancing nutrient absorption
2 capsule serving for maintaining levels around the clock
Third-party tested for purity
GMP Certified
100% Money-Back Guarantee

Read on to see what their happy customers are saying

“When you get to be my age, Vitamin D is so important to staying strong and healthy. I have friends who end up in the hospital when they get the flu or who are suffering from osteoporosis. Neither of those sound good to me and I’ll do anything in my power to stay healthy, which is why I take Vitamin D3+K2 daily. Normally I prefer my supplements to be vegan but I like that this supplement uses D3 which is more natural and used by our body better than synthetic vitamin D. So far, I’m happy with this product and will certainly buy again.”  – Lance Tyler

“I’ve been taking Vitamin D for some time now from a different brand and then I was visiting a friend when she opened the medicine cabinet to get me a pain killer and I noticed her Vitamin D was paired with K. I asked about it and she explained how important it is to take K when you take D so I made the switch and I don’t plan on going back anytime soon.” – Mariela Suarez

“My old Vitamin D and K pills had run out and when I went to order more, they were out of stock so I looked for a different brand and came across Approved Science. At first I thought this was too expensive for a simple multivitamin but then I read up on how each ingredient is in the optimal form and started to reconsider but I wasn’t really sold until I saw the multi-purchase options and realized that if I bought a few bottles at once then I could spend even less than the old brand that I was using.” – Isaiah Butler

“There’s a lot of Vitamin D in these pills which is perfect for me since I rarely get a chance to step outside into the daylight. My doctor told me that even if I were to lay in the sun for a week with no clothes on, I still wouldn’t produce enough Vitamin D to make up for my deficiency. I needed something high strength to help me get back on track, considering how important Vitamin D is for the immune system and supporting healthy bones. After my last follow up with my doctor, we found that my Vitamin D levels have gone up and are actually almost really good. This has been a true lifesaver and if you also don’t get enough sunlight I highly recommend taking Approved Science Vitamin D3+K2.”  – Daphne Evans

“Approved Science already helps me with my acid reflux and my husband with his cholesterol so when my doctor told me that I was vitamin D deficient, I immediately went online to Approved Science to see if they had a product for me. It’s a brand that I trust and I’ve compared their products to others and always found it to be the better option. This is my go-to Vitamin D supplement and if you’re deficient, this should really be yours too. With such a high daily dose and the added benefits of Vitamin K2, this really is a top quality supplement.”  – Sadie Wolff

“I’d never heard of K2 before but when I was looking for a vitamin D supplement, most of the products I saw contained it. I did a bit of research and decided it was what I needed. In addition to working with vitamin D, it also helps with heart health and preventing bone deterioration. Once I knew about K2, I started digging into the two types and trying to understand the difference and which I prefer. I was looking for something with MK-7 and a high trans percentage but most companies didn’t advertise that information. When I looked at the formula of Approved Science’s Vitamin D3+K2, I knew this was the real deal.” – Felix Duncan    

“For someone from the sunshine state, I really don’t get as much sunlight as you’d expect. Between working a corporate job and detesting the feel of sand between my toes, you can imagine I don’t get out much. I try to workout on my lunch hour but always inside where the air conditioning is going full blast. This has of course impacted my vitamin D levels and now I’m stuck taking pills to make up for my less than ideal lifestyle. Approved Science seems to be effective for keeping me from the brink of death and making up for where I lack. My doc says my levels are good now that I’ve been taking this. Maybe when I retire I’ll finally live a healthy lifestyle -ha!” – Mark Pines

FAQs about Approved Science Vitamin D3+K2:

How does Approved Science Vitamin D3+K2 work?

The key lies in having the right type of each vitamin (D3 and K2 MK-7) within the formula. With the optimal forms of D3 and K2, this product works on vanquishing vitamin deficiencies. Vitamin D is used for many roles throughout the body but is most known for its roles in bone health, the cardiovascular system, and the immune system.

In addition to helping modulate the immune system, this D3+K2 supplement increases Calcium absorption and helps to calcify the bones. This protects the bones by both building them up and preventing the body from siphoning off bone Calcium to maintain equilibrium in the blood. Additionally, this protects the arteries and kidneys from too much Calcium which could harden them. 

Lastly, BioPerine® increases nutrient absorption to ensure optimal results.

Do all Vitamin D3+K2 supplements work in a similar way?

No, they do not. There are many companies that just ride the trends, producing inferior products with weak formulas in the wrong proportions. Many use incorrect ingredients, fillers, binders or even worse ingredients that can affect desired results, and even be dangerous.

What should I look for in an effective Vitamin D supplement?

  • It should contain a daily dosage of 125mg of Vitamin D3.
  • It should provide a highly bioactive Vitamin K (~80% trans K2 MK-7) for effectively carrying the vitamin D directly to the bones. 
  • It should contain 180mcg of Vitamin K2.
  • It should contain BioPerine® or another bioavailability enhancer to optimize the results.
  • It must be 100% pure and natural, with no unnecessary ingredients that might reduce the effectiveness of the product.

Are there any side effects noted when using this product?

Our research did not uncover any negative side effects when using this product. The ingredients that are contained within the formula of Approved Science Vitamin D3+K2 are all natural and 100% pure. It should be noted that the K2 MK-7 is derived from natto and therefore contains soy so you should not use it if you have an allergy. However, if you do not have an allergy to soy then you shouldn’t experience any side effects. That said, as with any supplement, we always recommend consulting with a doctor if you are pregnant, breastfeeding, have an existing medical condition or are taking any other medication, especially anticoagulant medications.

What are the dosage instructions for Approved Science Vitamin D3+K2?

The manufacturers of this product suggest taking 2 capsules per day, 1 in the morning and one in the afternoon, before mealtime and with a glass of water. 

As with any supplement, always follow the recommended dosage instructions and do not exceed them as this poses health risks.

How long before I can see any results?

Results will vary for each person depending on their deficiency. For some, they will see changes in a few weeks, while for others it may take longer. It is different for each person. Other factors that affect results can include age, diet, and lifestyle so it is hard to say exactly. What you should look for are companies who offer a satisfaction guarantee. This suggests that they are confident that their products will deliver the desired results. And after all, if you don’t get the results you were hoping for you can always return the product. Approved Science Vitamin D3+K2 offers a great money-back guarantee and awesome feedback on how well this product works.

What price should I expect to pay?

The cost of products vary among manufacturers. Unfortunately, many are cheap, useless supplements that have no science-based evidence to back up their formulas. Some of these companies are selling their products for around $100 per bottle, which is very expensive. On average, the best supplements we found are selling between the $40-$50 price range. Often, when products appear cheaper, this is indicative of low quality or a low recommended daily serving, which will not bring the results you are looking for. Be aware. Read the labels.

Which Vitamin D3+K2 supplement should I buy?

As each person’s experience of a product is different, it is difficult to say specifically which one is the best. That said, based on several factors, we did like Approved Science Vitamin D3+K2. We found that from the 50+ products that we looked at, Approved Science Vitamin D3+K2 had the best quality of ingredients, potency and strength, positive consumer feedback, and excellent customer service.

How safe is it to order over the internet?

Ordering Vitamin D3+K2 from Approved Science is safe to do over the internet. The manufacturer utilizes the latest encryption software to protect your credit card information and does not engage in shady schemes such as ‘automatic billing’ programs like many other companies do. They also deliver very efficiently and quickly, using discreet packaging.

Why should I choose Approved Science Vitamin D3+K2?

There are several reasons why we liked this product including purity of ingredients, customer service, satisfaction, and effectiveness. Its formula is backed by clinical studies and we feel it values consumers’ health above and beyond the profit margins.

Approved Science Vitamin D3+K2 is a great product that you can depend on. It has a well-researched formula with the right ingredients in the correct potency. And if that wasn’t enough, check out the customer reviews – they say it all. It counts when there are many happy customers who are highly loyal to this brand clearly singing the praises of this trustworthy product. We will summarize the key benefits one more time:

  • Helps improve vitamin deficiencies.
  • Assists the immune system and may reduce the risk of the flu or heart disease.
  • Improves Calcium absorption which aids bone building and maintenance.
  • Provides 5000IU/125mcg vitamin D as recommended by the Vitamin D Council.
  • Contains vitamin D3 which is natural, unlike D2.
  • Contains highly active vitamin K: 80% trans K2 Mk-7. 
  • Contains BioPerine® for optimizing nutrient absorption.
  • No preservatives, artificial colorings, hormones, or unnecessary ingredients that may dilute the efficacy of the product.

In addition to the above points, we found so many supportive consumer reviews from users who had experienced excellent results, some within as little as a week. Its daily suggested serving is the optimal potency as recommended by doctors for effectiveness and is supported by clinical research trials and studies. This manufacturer’s customer service is second to none; it provides excellent support and help. Furthermore, it offers an excellent money-back guarantee if customers are not satisfied with their results.

The Bottom Line

At the end of the day, consumers have so many options when choosing a Vitamin D3 supplement. Advertisers are always trying to convince us that their product is something that we just have to have, even if it isn’t good for us. It can be exhausting to figure out which products really have legitimacy and value. After some serious searching, we finally found a product that meets our standards and even exceeds some of them!

We like Approved Science because we feel that this company is different. It is in it for the long haul. It has researched its ingredients well and produced its formula using only pure natural ingredients with a lot of clinical data to back them up. Approved Science offers what more companies should – an effective, affordable product supported by a real concern for the health of its customers. As an added bonus, Approved Science Vitamin D3+K2 has many happy testimonials to support our belief that this is a great product and a great company.   

What You’ll Discover:

Which Vitamin D3 supplement is the BEST BUY and comes with a great GUARANTEE!
Which formula and ingredients are the most EFFECTIVE and work the fastest?
How NOT to get ripped off! BE AWARE of poor quality and cheap products.

Top 6 Items to Consider:

  1. Ingredients
  2. Cost Per Serving
  3. Product’s Testing Results
  4. Company’s Reputation
  5. Consumer Reviews
  6. Return Policy & Satisfaction Guarantee

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