Solgar Vitamin D3 1000 IU (25mcg) Softgels - 250 Count vs Vitamin D3 5000 IU
Side-by-side comparison of scores, ingredients, prices and real customer feedback for Solgar Vitamin D3 1000 IU (25mcg) Softgels - 250 Count and Vitamin D3 5000 IU.
Last verified: 07 Apr 2026 · Based on 66 reviews
Solgar Vitamin D3 1000 IU (25mcg) Softgels - 250 Count scores 83.0/100 vs Vitamin D3 5000 IU at 81.0/100. Solgar Vitamin D3 1000 IU (25mcg) Softgels - 250 Count wins on value for money, side effects. Vitamin D3 5000 IU is stronger on effectiveness and ingredient quality.
Which is better: Solgar Vitamin D3 1000 IU (... or Vitamin D3 5000 IU?
Solgar wins on score (83 vs 81) and value at £11.16 for 250 softgels—its 1000 IU dose is ideal for daily maintenance. Thorne's 5000 IU suits those with confirmed deficiency, though it costs significantly more.
— AIScored Editorial Team
How Do the Scores Compare?
Solgar Vitamin D3 1000 IU (...
Solgar
|
Vitamin D3 5000 IU
Thorne
|
|
|---|---|---|
| Overall Score | 83.0 | 81.0 |
| Effectiveness | 81.0/100 |
82.0/100
Best
|
| Ingredient Quality | 89.0/100 |
90.0/100
Best
|
| Value for Money |
86.0/100
Best
|
66.0/100 |
| Side Effects |
92.0/100
Best
|
80.0/100 |
| Certifications | 68.0/100 |
88.0/100
Best
|
| Best Price |
£11.16
Amazon UK →
Cheapest
|
View → |
| Price per Serving | £0.04 250 servings | N/A |
| Form | Softgels | N/A |
| Dose | 1000 IU (25mcg) Vitamin D3 | N/A |
| Third-Party Tested | ✗ No | ✗ No |
| Reviews Analysed | 56 | 10 |
Solgar Vitamin D3 1000 IU (25mcg...
Pros
- ✓Small, easy-to-swallow softgels with no taste or odour — universally noted across reviews
- ✓Exceptionally clean formulation: only safflower oil and gelatin shell, no magnesium stearate or silicon dioxide
- ✓250-count bottle offers excellent long-term value — up to ~8 months supply at 1/day
- ✓Reviewers consistently report improved energy, mood, and immunity — consistent with D3 research evidence
Cons
- ✗1000 IU is a maintenance dose only — insufficient to correct deficiency; those with low D levels typically need 2000–5000 IU under guidance
- ✗Not third-party tested (e.g. NSF, Informed Sport) — limits verification for athletes or those requiring assay confirmation
- ✗Contains bovine gelatin — not suitable for vegans, vegetarians, or some religious dietary requirements (halal concerns raised by reviewers)
- ✗Safflower oil carrier is functional but not as optimal as olive oil or MCT oil for fat-soluble vitamin absorption
Best For
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
What does the data say about Solgar Vitamin D3 1000... vs Vitamin D3 5000 IU?
Solgar's 1000 IU softgels (83/100) and Thorne's 5000 IU formula (81/100) target different needs. The core difference is dose: 1000 IU maintains healthy levels, while 5000 IU corrects deficiency. Solgar's formulation is exceptionally clean — only safflower oil and gelatin, no fillers. At £11.16 for 250 softgels, that's roughly 8 months of supply.
Thorne includes K2 MK7 with its D3, which helps direct calcium to bone rather than soft tissue. This synergy is research-backed and valuable if blood tests confirm deficiency. However, 5000 IU shouldn't be used for general maintenance without medical guidance.
Pick Solgar if you're maintaining normal levels or live in low-sun climates — the small softgels are easy to swallow and the dose is safe long-term. Choose Thorne if deficiency testing shows you need it, though you'll pay more per dose. Both lack third-party testing, so purity assurance depends on brand reputation.
Solgar Vitamin D3 1000 IU is a well-regarded maintenance-dose supplement in a 250-count softgel format, praised by reviewers for its small capsule size, easy swallowability, and clean formulation.
What are the key differences?
Frequently Asked Questions
Which is better, Solgar Vitamin D3 1000 IU (25mcg) Softgels - 250 Count or Vitamin D3 5000 IU? ▼
Is Solgar Vitamin D3 1000 IU (25mcg) Softgels - 250 Count worth the price compared to Vitamin D3 5000 IU? ▼
Which has fewer side effects? ▼
Related Product Comparisons
Nutri Advanced Vitamin D3 with K2 Liquid Drops 30ml
vs Solgar Vitamin D3 1000 IU (25mcg) Softgels - 250 Count
Nutri Advanced Vitamin D3 with K2 Liquid Drops 30ml
vs Vitamin D3 5000 IU
Solgar Vitamin D3 1000 IU (25mcg) Softgels - 250 Count
vs Vitamin D-3, High Potency, 2,000 IU, 240 Softgels
Solgar Vitamin D3 1000 IU (25mcg) Softgels - 250 Count
vs Vitamin D-3, High Potency, 5,000 IU, 120 Softgels
Solgar Vitamin D3 1000 IU (25mcg) Softgels - 250 Count
vs Vitamin D-3, High Potency, 5,000 IU, 240 Softgels
Solgar Vitamin D3 1000 IU (25mcg) Softgels - 250 Count
vs Vitamin D3, High Potency, 10,000 IU, 120 Softgels
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.
Feedback & Suggestions
Spotted an issue? Wrong price, incorrect data, or something else off? Let us know and we'll fix it.
Missing a product you'd like us to review? Tell us the product name and we'll consider adding it.