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Vitamin D-3, High Potency, 2,000 IU, 240 Softgels vs Nutravita Vitamin D3 4000 iu - 400 High Strength Easy to Swallow Premium Softgels - Over A Year's Supply - Max Strength Vitamin D3 Cholecalciferol Supplement - Manufactured in The UK

Side-by-side comparison of scores, ingredients, prices and real customer feedback for Vitamin D-3, High Potency, 2,000 IU, 240 Softgels and Nutravita Vitamin D3 4000 iu - 400 High Strength Easy to Swallow Premium Softgels - Over A Year's Supply - Max Strength Vitamin D3 Cholecalciferol Supplement - Manufactured in The UK.

Last verified: 07 Apr 2026 · Based on 67 reviews

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82.0
Quick Answer

Vitamin D-3, High Potency, 2,000 IU, 240 Softgels scores 82.0/100 vs Nutravita Vitamin D3 4000 iu - 400 High Strength Easy to Swallow Premium Softgels - Over A Year's Supply - Max Strength Vitamin D3 Cholecalciferol Supplement - Manufactured in The UK at 80.0/100. Vitamin D-3, High Potency, 2,000 IU, 240 Softgels wins on effectiveness, ingredient quality, side effects. Nutravita Vitamin D3 4000 iu - 400 High Strength Easy to Swallow Premium Softgels - Over A Year's Supply - Max Strength Vitamin D3 Cholecalciferol Supplement - Manufactured in The UK is stronger on certifications.

How Do the Scores Compare?

Vitamin D-3, High Potency, ...
Nutravita Vitamin D3 4000 i...
Vitamin D-3, High Potency, 2,000 IU, 240 Softgels
Vitamin D-3, High Potency, ...
NOW Foods
 Nutravita Vitamin D3 4000 iu - 400 High Strength Easy to Swallow Premium Softgels - Over A Year's Supply - Max Strength Vitamin D3 Cholecalciferol Supplement - Manufactured in The UK
Nutravita Vitamin D3 4000 i...
Nutravita
Overall Score 82.0 80.0
Effectiveness 82.0/100
Best
 80.0/100
Ingredient Quality 85.0/100
Best
 77.0/100
Value for Money 90.0/100
Best
 90.0/100
Best
Side Effects 93.0/100
Best
 88.0/100
Certifications 58.0/100 62.0/100
Best
Best Price £8.82 iHerb →
Cheapest
 £8.99 Amazon UK →
Form None Softgel
Dose None 116 Grams
Third-Party Tested ✗ No ✗ No
Reviews Analysed 50 17

Vitamin D-3, High Potency, 2,000...

Pros

  • ✓Small, tasteless softgels praised by nearly every reviewer — easy to swallow for adults and children alike
  • ✓240-count bottle lasts 8 months at one per day, making the per-dose cost very low
  • ✓Cholecalciferol delivered in olive oil — correct form and carrier for fat-soluble vitamin absorption
  • ✓Reviewers consistently report energy, mood, and immunity improvements over autumn-winter use

Cons

  • ✗Bovine gelatin capsule rules out vegans and some vegetarians — no plant-based equivalent in this line
  • ✗No independent third-party potency or purity testing (no iTested, NSF, or USP verification)
  • ✗2,000 IU is a maintenance dose, not a correction dose — several reviewers with confirmed deficiency needed higher amounts or separate high-dose protocols
  • ✗One reviewer flagged the lid pops open unexpectedly rather than staying sealed between uses

Best For

Adults maintaining adequate vitamin D levels through autumn and winter with limited sun exposure Families wanting a single affordable bottle that covers multiple people at a daily dose People who have corrected a deficiency with a higher-dose protocol and now need a straightforward maintenance supplement Anyone who struggles with large capsules — the softgel size is a genuine practical advantage here
iHerb £8.82
View full review →

Nutravita Vitamin D3 4000 iu - 4...

Pros

  • ✓Small, easy-to-swallow softgels praised by virtually every reviewer, including those with tablet-swallowing difficulties
  • ✓Excellent value for money — 400 softgels lasts over a year at one-per-day dosing
  • ✓Clean formula with no fillers, bulking agents, or anti-caking agents — just D3, sunflower oil, and gelatin
  • ✓High 4000 IU dose meets medically recommended therapeutic levels for deficiency without needing multiple capsules

Cons

  • ✗Gelatin (bovine) capsule — not suitable for vegetarians or vegans
  • ✗No independent third-party certification (no USP, NSF, or equivalent)
  • ✗4000 IU exceeds general population guidelines; those without confirmed deficiency should consult a doctor before use
  • ✗Not recommended for under-18s per product labelling, limiting household sharing

Best For

UK residents with limited sun exposure during autumn and winter People diagnosed with or at risk of vitamin D deficiency Adults who struggle to swallow large tablets or capsules Those wanting a clean-label supplement with minimal additives Budget-conscious buyers seeking a long-lasting supply
Amazon UK £8.99
View full review →

What does the data say about Vitamin D-3, High Pote... vs Nutravita Vitamin D3 4...?

Vitamin D-3, High Potency, 2,000 IU, 240 Softgels Winner 82.0/100

NOW Foods delivers 2,000 IU of cholecalciferol — the most bioavailable form of vitamin D — suspended in olive oil inside a small bovine gelatin softgel.

Effectiveness
Vitamin D-3, Hig..
82.0/100
Nutravita Vitami..
80.0/100
Ingredient Quality
Vitamin D-3, Hig..
85.0/100
Nutravita Vitami..
77.0/100
Value for Money
Vitamin D-3, Hig..
90.0/100
Nutravita Vitami..
90.0/100
Side Effects
Vitamin D-3, Hig..
93.0/100
Nutravita Vitami..
88.0/100
Certifications
Vitamin D-3, Hig..
58.0/100
Nutravita Vitami..
62.0/100

What are the key differences?

Vitamin D-3, High Poten.. is best for: Adults maintaining adequate vitamin D levels through autumn and winter with limited sun exposure, Families wanting a single affordable bottle that covers multiple people at a daily dose
Nutravita Vitamin D3 40.. is best for: UK residents with limited sun exposure during autumn and winter, People diagnosed with or at risk of vitamin D deficiency

Frequently Asked Questions

Which is better, Vitamin D-3, High Potency, 2,000 IU, 240 Softgels or Nutravita Vitamin D3 4000 iu - 400 High Strength Easy to Swallow Premium Softgels - Over A Year's Supply - Max Strength Vitamin D3 Cholecalciferol Supplement - Manufactured in The UK? ▼
Vitamin D-3, High Potency, 2,000 IU, 240 Softgels scores 82.0/100 overall while Nutravita Vitamin D3 4000 iu - 400 High Strength Easy to Swallow Premium Softgels - Over A Year's Supply - Max Strength Vitamin D3 Cholecalciferol Supplement - Manufactured in The UK scores 80.0/100. Vitamin D-3, High Potency, 2,000 IU, 240 Softgels comes out ahead, scoring higher on effectiveness (82.0 vs 80.0). Vitamin D-3, High Potency, 2,0 is best suited for Adults maintaining adequate vitamin D levels through autumn and winter with limited sun exposure and Families wanting a single affordable bottle that covers multiple people at a daily dose. Nutravita Vitamin D3 4000 iu - is better for UK residents with limited sun exposure during autumn and winter and People diagnosed with or at risk of vitamin D deficiency.
Is Vitamin D-3, High Potency, 2,000 IU, 240 Softgels worth the price compared to Nutravita Vitamin D3 4000 iu - 400 High Strength Easy to Swallow Premium Softgels - Over A Year's Supply - Max Strength Vitamin D3 Cholecalciferol Supplement - Manufactured in The UK? ▼
Vitamin D-3, High Potency, 2,000 IU, 240 Softgels costs £8.82 while Nutravita Vitamin D3 4000 iu - 400 High Strength Easy to Swallow Premium Softgels - Over A Year's Supply - Max Strength Vitamin D3 Cholecalciferol Supplement - Manufactured in The UK is £8.99. For value, Vitamin D-3, High Potency, 2,000 IU, 240 Softgels scores 90.0/100 vs Nutravita Vitamin D3 4000 iu - 400 High Strength Easy to Swallow Premium Softgels - Over A Year's Supply - Max Strength Vitamin D3 Cholecalciferol Supplement - Manufactured in The UK's 90.0/100. Both offer similar value for money.
Which has fewer side effects? ▼
Vitamin D-3, High Potency, 2,000 IU, 240 Softgels scores 93.0/100 for side effects (higher means fewer reported issues) while Nutravita Vitamin D3 4000 iu - 400 High Strength Easy to Swallow Premium Softgels - Over A Year's Supply - Max Strength Vitamin D3 Cholecalciferol Supplement - Manufactured in The UK scores 88.0/100. Reviewers report fewer side effects with Vitamin D-3, High Potency, 2,000 IU, 240 Softgels. For certification and testing, Vitamin D-3, High Po scores 58.0/100 vs Nutravita Vitamin D3's 62.0/100. Always consult a healthcare professional before starting any supplement.

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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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