Vitamin K2 + D3, Extra Strength, 120 Capsules vs Vitamins D and K with Sea-Iodine, 60 Capsules

Side-by-side comparison of scores, ingredients, prices and real customer feedback for Vitamin K2 + D3, Extra Strength, 120 Capsules and Vitamins D and K with Sea-Iodine, 60 Capsules.

Last verified: 07 Apr 2026 · Based on 100 reviews

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77.0

Quick Answer

Vitamin K2 + D3, Extra Strength, 120 Capsules scores 77.0/100 vs Vitamins D and K with Sea-Iodine, 60 Capsules at 73.0/100. Vitamin K2 + D3, Extra Strength, 120 Capsules wins on effectiveness, value for money, side effects. Vitamins D and K with Sea-Iodine, 60 Capsules is stronger on ingredient quality and certifications.

How Do the Scores Compare?

Vitamin K2 + D3, Extra Stre...

Vitamins D and K with Sea-I...

	Vitamin K2 + D3, Extra Stre... Futurebiotics	Vitamins D and K with Sea-I... Life Extension
Overall Score	77.0	73.0
Effectiveness	82.0/100 Best	77.0/100
Ingredient Quality	80.0/100	82.0/100 Best
Value for Money	87.0/100 Best	68.0/100
Side Effects	91.0/100 Best	80.0/100
Certifications	37.0/100	38.0/100 Best
Best Price	£14.72 iHerb →	£14.36 iHerb → Cheapest
Form	None	None
Dose	None	None
Third-Party Tested	✗ No	✗ No
Reviews Analysed	50	50

Vitamin K2 + D3, Extra Strength,...

Pros

✓10,000 IU suits people with confirmed deficiency — multiple reviewers specifically switched from 5,000 IU after failing to hit target levels
✓K2 as MK-7 (120 mcg) is the superior form: long half-life means once-daily dosing works, and the dose sits in the effective range used in studies
✓Clean excipient list — microcrystalline cellulose, cellulose capsule, magnesium stearate, silicon dioxide — no soy, gluten, or fillers reviewers flag
✓120 capsules gives four months at daily use; reviewers consistently cite strong value versus pharmacy pricing

Cons

✗No independent third-party testing — label says 'Lab Tested' but this is self-declared; specs confirm no external verification
✗10,000 IU is not a maintenance dose — requires blood testing before and during use; one reviewer explicitly notes skipping this step and risking over-supplementation
✗D3 sourced from lanolin (standard cholecalciferol) — not suitable for vegans despite the cellulose capsule shell
✗K2 form is unbranded MK-7, not a patented ingredient like MenaQ7 — potency and purity can vary without third-party confirmation

Best For

Adults with blood-confirmed vitamin D deficiency who haven't responded to 5,000 IU doses People in northern climates or desk-bound lifestyles with minimal sun exposure Anyone seeking a combined bone and calcium metabolism formula without paying for a premium brand Budget-conscious buyers who want MK-7 specifically rather than cheaper MK-4 products

iHerb £14.72

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Vitamins D and K with Sea-Iodine...

Pros

✓D3 at 5,000 IU is a meaningful therapeutic dose for deficiency — multiple reviewers specifically bought it to address low vitamin D
✓MK-7 form of K2 is the right choice for calcium regulation; reviewers with endocrinologist guidance specifically chose this product
✓Marine-sourced iodine for thyroid support, noted by several reviewers as preferable to synthetic potassium iodide
✓Capsules consistently praised as small and easy to swallow — no discomfort reported

Cons

✗1,000 mcg iodine is at the tolerable upper limit; one reviewer explicitly warns this dose is not suitable for continuous daily use without monitoring
✗No third-party testing confirmed — Life Extension has a strong reputation, but no independent verification of label accuracy or contamination testing
✗Noticeably more expensive than standalone D3 products — one reviewer specifically compared it unfavourably to basic Thorne D3 drops on price
✗Not vegan, which limits suitability for plant-based users

Best For

People with confirmed vitamin D deficiency who also want calcium-routing K2 support in one capsule Those with low sun exposure — referenced by multiple reviewers as the core reason for purchase Post-partum women — several reviewers specifically mentioned using it after pregnancy and breastfeeding to address multiple deficiencies Anyone wanting D3+K2+iodine without managing three separate supplements

iHerb £14.36

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What does the data say about Vitamin K2 + D3, Extra... vs Vitamins D and K with ...?

Both products score 78/100, but the gap between them is wider than that suggests. Futurebiotics delivers 10,000 IU of D3 paired with MK-7 K2 — the long-acting form — across 120 capsules for £14.72, which works out to roughly 12p per day. Life Extension goes a different route: 5,000 IU D3 with a triple-form vitamin K stack (K1, MK-4, and MK-7 totalling 2,100 mcg) plus 1,000 mcg of sea-derived iodine, all in 60 capsules at £14.36. The value scores reflect this: Futurebiotics hits 87/100 for value while Life Extension trails at 70/100, partly because you get half as many capsules at nearly the same price.

Who should pick which depends almost entirely on your situation. The Futurebiotics option suits people with blood-test confirmed deficiency who need a corrective dose under medical guidance — 10,000 IU daily is not for casual use without monitoring. Life Extension fits better for those running a therapeutic 5,000 IU course who also want iodine covered, provided they don't have thyroid conditions. That 1,000 mcg iodine dose is a genuine contraindication for Hashimoto's sufferers.

Neither product carries third-party certification — no NSF, USP, or Informed Sport mark — so you're relying on brand trust alone at this price point.

Vitamin K2 + D3, Extra Strength, 120 Capsules Winner 77.0/100

At 10,000 IU of cholecalciferol paired with 120 mcg of MK-7 menaquinone, this is a therapeutic-strength formula built for correcting deficiency rather than just maintaining levels.

Effectiveness

Vitamin K2 + D3,..

82.0/100

Vitamins D and K..

77.0/100

Ingredient Quality

Vitamin K2 + D3,..

80.0/100

Vitamins D and K..

82.0/100

Value for Money

Vitamin K2 + D3,..

87.0/100

Vitamins D and K..

68.0/100

Side Effects

Vitamin K2 + D3,..

91.0/100

Vitamins D and K..

80.0/100

Certifications

Vitamin K2 + D3,..

37.0/100

Vitamins D and K..

38.0/100

What are the key differences?

Vitamin K2 + D3, Extra .. is best for: Adults with blood-confirmed vitamin D deficiency who haven't responded to 5,000 IU doses, People in northern climates or desk-bound lifestyles with minimal sun exposure

Vitamins D and K with S.. is best for: People with confirmed vitamin D deficiency who also want calcium-routing K2 support in one capsule, Those with low sun exposure — referenced by multiple reviewers as the core reason for purchase

Frequently Asked Questions

Which is better, Vitamin K2 + D3, Extra Strength, 120 Capsules or Vitamins D and K with Sea-Iodine, 60 Capsules? ▼

Vitamin K2 + D3, Extra Strength, 120 Capsules scores 77.0/100 overall while Vitamins D and K with Sea-Iodine, 60 Capsules scores 73.0/100. Vitamin K2 + D3, Extra Strength, 120 Capsules comes out ahead, scoring higher on effectiveness (82.0 vs 77.0). Vitamin K2 + D3, Extra Strengt is best suited for Adults with blood-confirmed vitamin D deficiency who haven't responded to 5,000 IU doses and People in northern climates or desk-bound lifestyles with minimal sun exposure. Vitamins D and K with Sea-Iodi is better for People with confirmed vitamin D deficiency who also want calcium-routing K2 support in one capsule and Those with low sun exposure — referenced by multiple reviewers as the core reason for purchase.

Is Vitamin K2 + D3, Extra Strength, 120 Capsules worth the price compared to Vitamins D and K with Sea-Iodine, 60 Capsules? ▼

Vitamin K2 + D3, Extra Strength, 120 Capsules costs £14.72 while Vitamins D and K with Sea-Iodine, 60 Capsules is £14.36. For value, Vitamin K2 + D3, Extra Strength, 120 Capsules scores 87.0/100 vs Vitamins D and K with Sea-Iodine, 60 Capsules's 68.0/100. Vitamin K2 + D3, Extra Strength, 120 Capsules delivers better value relative to its quality.

Which has fewer side effects? ▼

Vitamin K2 + D3, Extra Strength, 120 Capsules scores 91.0/100 for side effects (higher means fewer reported issues) while Vitamins D and K with Sea-Iodine, 60 Capsules scores 80.0/100. Reviewers report fewer side effects with Vitamin K2 + D3, Extra Strength, 120 Capsules. For certification and testing, Vitamin K2 + D3, Ext scores 37.0/100 vs Vitamins D and K wit's 38.0/100. Always consult a healthcare professional before starting any supplement.

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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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