Vitamin D-3, High Potency, 5,000 IU, 240 Softgels vs Vitamin D3, High Potency, 10,000 IU, 120 Softgels
Side-by-side comparison of scores, ingredients, prices and real customer feedback for Vitamin D-3, High Potency, 5,000 IU, 240 Softgels and Vitamin D3, High Potency, 10,000 IU, 120 Softgels.
Last verified: 07 Apr 2026 · Based on 100 reviews
Vitamin D-3, High Potency, 5,000 IU, 240 Softgels scores 82.0/100 vs Vitamin D3, High Potency, 10,000 IU, 120 Softgels at 82.0/100. Vitamin D-3, High Potency, 5,000 IU, 240 Softgels wins on value for money, side effects. Vitamin D3, High Potency, 10,000 IU, 120 Softgels is stronger on effectiveness and ingredient quality.
Which is better: Vitamin D-3, High Potency, ... or Vitamin D3, High Potency, 1...?
NOW Foods Vitamin D-3 5,000 IU wins: 240 softgels for £11.93 beats the 10,000 IU's 120 softgels at £8.82 on value (91.0 vs 89.0). Pick the 10,000 IU if severe deficiency requires higher immediate dosing.
— AIScored Editorial Team
How Do the Scores Compare?
Vitamin D-3, High Potency, ...
NOW Foods
|
Vitamin D3, High Potency, 1...
NOW Foods
|
|
|---|---|---|
| Overall Score | 82.0 | 82.0 |
| Effectiveness | 85.0/100 |
86.0/100
Best
|
| Ingredient Quality | 83.0/100 |
84.0/100
Best
|
| Value for Money |
91.0/100
Best
|
89.0/100 |
| Side Effects |
87.0/100
Best
|
76.0/100 |
| Certifications |
52.0/100
Best
|
52.0/100
Best
|
| Best Price | £11.93 iHerb → |
£8.82
iHerb →
Cheapest
|
| Form | None | None |
| Dose | None | None |
| Third-Party Tested | ✗ No | ✗ No |
| Reviews Analysed | 50 | 50 |
Vitamin D-3, High Potency, 5,000...
Pros
- ✓Cholecalciferol (D3) in olive oil — correct form and fat-soluble delivery for meaningful absorption
- ✓240 softgels at 5,000 IU is exceptional value; multiple reviewers explicitly note how long a single purchase lasts
- ✓Tiny, tasteless, odourless softgels — easy to swallow, praised consistently across dozens of reviews
- ✓Several reviewers confirm blood levels normalised after taking this at a doctor-recommended 5,000 IU dose
Cons
- ✗Not vegan — bovine gelatin capsule shell rules it out for plant-based users
- ✗No independent third-party purity or potency testing (no NSF, USP, or equivalent verification)
- ✗5,000 IU is a therapeutic dose, not a maintenance dose — appropriate only with confirmed deficiency and blood monitoring
- ✗No K2 included; several reviewers specifically flag that K2 should be taken separately to direct calcium properly
Best For
Vitamin D3, High Potency, 10,000...
Pros
- ✓10,000 IU of D3 (cholecalciferol) — the superior form over D2, and genuinely useful for correcting significant deficiency quickly
- ✓Softgel in olive oil base supports fat-soluble absorption; reviewers consistently take it with fat-containing meals for best results
- ✓Multiple reviewers confirm measurable increases in blood vitamin D levels after a course of supplementation
- ✓Small capsules praised across dozens of reviews — easy to swallow, no taste or smell
Cons
- ✗No K2 included — a recurring complaint, as several reviewers specifically note they purchase K2 separately when using this high dose
- ✗Contains bovine gelatin; not suitable for vegans or vegetarians
- ✗No third-party testing; quality assurance relies entirely on NOW Foods' in-house GMP processes
- ✗10,000 IU requires blood level monitoring — several reviewers warn about the risk of overshooting if taken daily without testing
Best For
What does the data say about Vitamin D-3, High Pote... vs Vitamin D3, High Poten...?
Both of these NOW Foods D3 products deliver cholecalciferol in oil-based softgels—the correct form and delivery method for a fat-soluble vitamin. The main difference is dosage and frequency. Product A offers 5,000 IU per softgel (240 per bottle, £11.93), while Product B contains 10,000 IU in 120 softgels at £8.82. If you take one daily, Product A lasts eight months; Product B lets you dose every 2–3 days instead.
Product A (84.0/100) suits daily users who want lower per-dose amounts. The value score of 93.0/100 reflects genuine savings spread across 240 softgels. Product B (83.0/100) appeals to those needing rapid correction or anyone who dislikes daily supplementing. Its value score of 91.0/100 reflects a higher upfront dose without frequent restocking.
Both softgels glide down easily with no taste. Both contain bovine gelatin, so vegans should look elsewhere. Neither product carries NSF, USP, or Informed Sport certification—reviewers have corrected low blood D3 levels with both, but there's no independent label verification. Choose based on dosing frequency and how long you want your bottle to last.
5,000 IU of cholecalciferol delivered in an extra virgin olive oil base — the fat-soluble carrier is correct science, not a gimmick.
What are the key differences?
Frequently Asked Questions
Which is better, Vitamin D-3, High Potency, 5,000 IU, 240 Softgels or Vitamin D3, High Potency, 10,000 IU, 120 Softgels? ▼
Is Vitamin D-3, High Potency, 5,000 IU, 240 Softgels worth the price compared to Vitamin D3, High Potency, 10,000 IU, 120 Softgels? ▼
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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