Vitamin D3 5000 IU vs Vitamin K2 + Vitamin D3, 120 Capsules
Side-by-side comparison of scores, ingredients, prices and real customer feedback for Vitamin D3 5000 IU and Vitamin K2 + Vitamin D3, 120 Capsules.
Last verified: 07 Apr 2026 · Based on 59 reviews
Vitamin D3 5000 IU scores 81.0/100 vs Vitamin K2 + Vitamin D3, 120 Capsules at 81.0/100. Vitamin D3 5000 IU wins on ingredient quality, certifications. Vitamin K2 + Vitamin D3, 120 Capsules is stronger on value for money and side effects.
Which is better: Vitamin D3 5000 IU or Vitamin K2 + Vitamin D3, 12...?
Nutricost Vitamin K2 + Vitamin D3 wins on value: £12.96 and a 91.0 value score versus Thorne's 66.0. Both deliver 81.0 overall scores with matching 82.0 effectiveness, but Nutricost combines K2+D3 for less than half the cost. Pick Thorne only if ingredient quality tops your list — it scores 90.0 to Nutricost's 84.0.
— AIScored Editorial Team
How Do the Scores Compare?
Vitamin D3 5000 IU
Thorne
|
Vitamin K2 + Vitamin D3, 12...
Nutricost
|
|
|---|---|---|
| Overall Score | 81.0 | 81.0 |
| Effectiveness |
82.0/100
Best
|
82.0/100
Best
|
| Ingredient Quality |
90.0/100
Best
|
84.0/100 |
| Value for Money | 66.0/100 |
91.0/100
Best
|
| Side Effects | 80.0/100 |
87.0/100
Best
|
| Certifications |
88.0/100
Best
|
42.0/100 |
| Best Price | View → |
£12.96
iHerb →
Cheapest
|
| Form | N/A | None |
| Dose | N/A | None |
| Third-Party Tested | ✗ No | ✗ No |
| Reviews Analysed | 10 | 49 |
Vitamin D3 5000 IU
Pros
- ✓Thorne Research is NSF Certified for Sport — independently tested for purity and label accuracy
- ✓Cholecalciferol (D3) is the most bioavailable and research-supported form of vitamin D
- ✓D3+K2 MK7 combination helps direct calcium to bones rather than arteries — evidence-backed synergy
- ✓Liquid format (30ml) allows flexible dosing and faster absorption than capsules
Cons
- ✗5000 IU is a high therapeutic dose — not appropriate for general daily use without a confirmed deficiency test
- ✗Premium price point compared to generic D3 supplements
- ✗Liquid format requires careful dosing to avoid over-supplementation
- ✗Fat-soluble vitamin — must be taken with a meal containing fat for optimal absorption
Best For
Vitamin K2 + Vitamin D3, 120 Capsules
Pros
- ✓K2 is supplied as MK-7 (menaquinone-7) — the longer-acting form with significantly better bioavailability than the cheaper MK-4 used in many budget products
- ✓5000 IU D3 is a genuinely effective dose for correcting deficiency, not the token 400–1000 IU found in most multivitamins
- ✓Softgel format in sunflower oil delivers fat-soluble vitamins in their ideal absorption medium
- ✓120 softgels at four months' supply represents strong value — reviewers repeatedly flag the price-to-quantity ratio as a key reason to buy
Cons
- ✗No verified third-party batch testing — the product specs confirm third_party_tested is false, despite some label copy referencing lab testing
- ✗Gelatin softgel is not suitable for vegans or vegetarians
- ✗5000 IU daily is a high-dose protocol; without blood monitoring it is easy to overshoot optimal levels long-term
- ✗K2 at 100 mcg is workable but some clinical protocols use 180–200 mcg alongside high-dose D3
Best For
What does the data say about Vitamin D3 5000 IU vs Vitamin K2 + Vitamin D...?
Thorne's Vitamin D3 5000 IU delivers 5000 IU of cholecalciferol in a simple capsule without any added K2. Nutricost's Vitamin K2 + Vitamin D3 packs the same 5000 IU D3 dose together with MK-7 K2 in 120 softgels made with sunflower oil for better absorption of these fat-soluble nutrients. Both products score 81.0/100 overall and tie on effectiveness at 82.0/100. Thorne pulls ahead on ingredient quality with 90/100 against Nutricost's 84/100 yet falls short on value at 66/100 compared to Nutricost's 91/100 score and its clear price of £12.96.
Pick Thorne if you already get enough K2 from food or other supplements and want a focused high-dose D3 option without extras. It suits adults over 50 or indoor workers in northern UK areas who have confirmed deficiency through blood tests. Choose Nutricost instead when you need the D3 and K2 combo in one product to help steer calcium toward bones rather than arteries. This fits people over 40 on a tighter budget who want to fix a suspected shortfall without buying two separate bottles.
The Nutricost softgels come in a standard size that most people swallow easily though the gelatin makes them unsuitable for vegans. Thorne capsules avoid that issue and have no reported taste problems from users. Both work best taken with a meal that contains some fat to aid uptake.
Thorne's Vitamin D3 5000 IU is a high-potency cholecalciferol supplement from one of the most rigorously tested supplement brands in the industry, known for NSF Certified for Sport status and clean formulations.
What are the key differences?
Frequently Asked Questions
Which is better, Vitamin D3 5000 IU or Vitamin K2 + Vitamin D3, 120 Capsules? ▼
Is Vitamin D3 5000 IU worth the price compared to Vitamin K2 + Vitamin D3, 120 Capsules? ▼
Which has fewer side effects? ▼
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What the Data Says
Why do 97% of UK vitamin D supplements lack third-party certification?
Only 1 out of 35 vitamin D products we scored has independent certification. That's 97% without any third-party verification of purity, potency, or label accuracy.
This is worse than most supplement categories. The reason is simple: UK law doesn't require it, and testing costs money. Most vitamin D brands sell on price alone, especially in the D3-only space where the raw ingredient is cheap. Certification adds cost that budget brands won't absorb.
What does this mean for you? Without third-party testing, you're trusting the manufacturer's label claims. A 2021 study in Nutrients found that vitamin D supplements varied from 52% to 135% of their labelled dose. That's a problem if you're relying on a specific daily intake.
Among the 35 products we scored, the top performers are all from brands with strong manufacturing track records: NOW Foods D3 5000 IU and Thorne Vitamin D + K2 both score 87/100 overall. Thorne holds the highest certification score in the category at 85/100. If independent testing matters to you, that's the product to look at.
Do you need vitamin K2 with high-dose vitamin D?
Probably yes at high doses, and our data backs the pairing. Thorne Vitamin D + K2 Liquid is the only D3+K2 combo product in our 35-product database that scores 87/100 overall, matching the top-ranked D3-only options from NOW Foods. It also holds the highest certification score in the category at 85/100.
Here's the science behind it. Vitamin D increases calcium absorption from food. Vitamin K2 activates proteins that direct that calcium into bones and teeth, keeping it out of your arteries and soft tissue. At standard doses (1000-2000 IU daily), most people get enough K2 from diet to handle the extra calcium. At 4000-5000 IU daily, the calcium load increases enough that K2 becomes a more serious consideration.
The Endocrine Society doesn't yet include K2 in its vitamin D guidelines. But a growing body of research, including a 2019 meta-analysis in International Journal of Molecular Sciences, shows the D3+K2 combination improves bone mineral density more than D3 alone.
If you eat K2-rich foods regularly (natto, hard cheese, egg yolks, chicken liver), a standalone D3 product like NOW Foods D3 5000 IU 360 Softgels (87/100) is a solid choice. If your diet is low in K2, or you're taking 4000+ IU of D3 daily, Thorne D + K2 covers both bases in one product.
Disclaimer: AIScored provides data-driven comparisons based on publicly available reviews. This is not medical advice. Affiliate links may earn us a commission at no extra cost to you.
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