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Nutricost Vitamin K2 MK-7 vs Life Extension D and K with Sea-Iodine

Side-by-side comparison of scores, ingredients, prices and real customer feedback for Nutricost Vitamin K2 MK-7 and Life Extension D and K with Sea-Iodine.

Last verified: 28 Mar 2026 · Based on 100 reviews

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76.0
Score Summary

Nutricost Vitamin K2 MK-7 scores 76.0/100 vs Life Extension D and K with Sea-Iodine at 73.0/100. Nutricost Vitamin K2 MK-7 wins on effectiveness, value for money, side effects. Life Extension D and K with Sea-Iodine is stronger on ingredient quality.

How Do the Scores Compare?

Vitamin K2 MK-7, 100 mcg, 2...
Vitamins D and K with Sea-I...
Vitamin K2 MK-7, 100 mcg, 240 Capsules
Vitamin K2 MK-7, 100 mcg, 2...
Nutricost
 Vitamins D and K with Sea-Iodine, 60 Capsules
Vitamins D and K with Sea-I...
Life Extension
Overall Score 76.0 73.0
Effectiveness 78.0/100
Best
 77.0/100
Ingredient Quality 73.0/100 82.0/100
Best
Value for Money 92.0/100
Best
 68.0/100
Side Effects 82.0/100
Best
 80.0/100
Certifications 42.0/100
Best
 38.0/100
Best Price £15.00 iHerb → £14.49 iHerb →
Cheapest
Form None None
Dose None None
Third-Party Tested ✗ No ✗ No
Reviews Analysed 50 50

Vitamin K2 MK-7, 100 mcg, 240 Capsules

Pros

  • ✓240-capsule bottle makes this one of the cheapest per-serving K2 MK-7 options — repeatedly highlighted by reviewers as the primary buying reason
  • ✓MK-7 form has a long half-life (~72 hours), making once-daily dosing genuinely effective rather than a convenience compromise
  • ✓Small softgels with no taste or aftertaste — multiple reviewers with swallowing difficulties specifically flag this
  • ✓Minimal ingredient list: MK-7, sunflower oil, gelatin capsule — no unnecessary fillers beyond the caramel capsule colouring

Cons

  • ✗Gelatin capsules — not suitable for vegans or vegetarians
  • ✗Caramel colouring in the capsule shell uses ammonia-based processing; flagged by at least one reviewer with multiple chemical sensitivities
  • ✗One reviewer notes the brand does not publish isomer data — unclear what percentage is all-trans MK-7 (the active form) versus cis
  • ✗Rare reports of heart palpitations and anxiety, particularly when combined with high-dose vitamin D3

Best For

Anyone already taking vitamin D3 who needs K2 to ensure calcium is deposited in bones rather than soft tissue Budget-conscious buyers wanting a long-lasting single-ingredient K2 supplement People who struggle with large capsules — the softgels are notably small Those who prefer buying D3 and K2 separately to control individual doses
iHerb £15.00
View full review →

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 £14.49
View full review →

Score Breakdown: Nutricost Vitamin K2 MK-7 vs Life Extension D and K with Sea-Iodine

Nutricost Vitamin K2 MK-7 Winner 76.0/100

At 100 mcg of MK-7 per softgel across 240 capsules, this is consistently cited as one of the best-value K2 options available — nearly every reviewer flags the price-per-serving as a key reason to buy.

Effectiveness
Vitamin K2 MK-7,..
78.0/100
Vitamins D and K..
77.0/100
Ingredient Quality
Vitamin K2 MK-7,..
73.0/100
Vitamins D and K..
82.0/100
Value for Money
Vitamin K2 MK-7,..
92.0/100
Vitamins D and K..
68.0/100
Side Effects
Vitamin K2 MK-7,..
82.0/100
Vitamins D and K..
80.0/100
Certifications
Vitamin K2 MK-7,..
42.0/100
Vitamins D and K..
38.0/100

What are the key differences?

Nutricost Vitamin K2 MK-7 is best for: Anyone already taking vitamin D3 who needs K2 to ensure calcium is deposited in bones rather than soft tissue, Budget-conscious buyers wanting a long-lasting single-ingredient K2 supplement
Life Extension D and K with Sea-Iodine 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, Nutricost Vitamin K2 MK-7 or Life Extension D and K with Sea-Iodine? ▼
Nutricost Vitamin K2 MK-7 scores 76.0/100 overall while Life Extension D and K with Sea-Iodine scores 73.0/100. Nutricost Vitamin K2 MK-7 comes out ahead, scoring higher on effectiveness (78.0 vs 77.0). Nutricost Vitamin K2 MK-7 is best suited for Anyone already taking vitamin D3 who needs K2 to ensure calcium is deposited in bones rather than soft tissue and Budget-conscious buyers wanting a long-lasting single-ingredient K2 supplement. Life Extension D and K with Sea-Iodine 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 Nutricost Vitamin K2 MK-7 worth the price compared to Life Extension D and K with Sea-Iodine? ▼
Nutricost Vitamin K2 MK-7 costs £15.00 while Life Extension D and K with Sea-Iodine is £14.49. For value, Nutricost Vitamin K2 MK-7 scores 92.0/100 vs Life Extension D and K with Sea-Iodine's 68.0/100. Nutricost Vitamin K2 MK-7 delivers better value relative to its quality.
Which has fewer side effects? ▼
Nutricost Vitamin K2 MK-7 scores 82.0/100 for side effects (higher means fewer reported issues) while Life Extension D and K with Sea-Iodine scores 80.0/100. Reviewers report fewer side effects with Nutricost Vitamin K2 MK-7. For certification and testing, Nutricost Vitamin K2 MK-7 scores 42.0/100 vs Life Extension D and K with Sea-Iodine'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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