NOW Foods MK-7 Vitamin K-2 vs Life Extension D and K with Sea-Iodine
Side-by-side comparison of scores, ingredients, prices and real customer feedback for NOW Foods MK-7 Vitamin K-2 and Life Extension D and K with Sea-Iodine.
Last verified: 28 Mar 2026 · Based on 100 reviews
Our Verdict: NOW Foods MK-7 Vitamin K-2 or Life Extension D and K with Sea-Iodine?
NOW Foods MK-7 wins with an 83 vs 79 overall score, stronger value (86 vs 71), and no concerns about excessive iodine or high-dose D3 requiring blood monitoring. The Life Extension option suits those who want D3, K2, and iodine in one capsule and are under medical supervision — its 5,000 IU D3 and 1,000 mcg iodine demand clinical oversight.
— AIScored Editorial Team
NOW Foods MK-7 Vitamin K-2 scores 83.0/100 vs Life Extension D and K with Sea-Iodine at 73.0/100. NOW Foods MK-7 Vitamin K-2 wins on effectiveness, ingredient quality, value for money.
NOW Foods MK-7 Vitamin K-2 vs Life Extension D and K with Sea-Iodine: What Does the Data Say?
MK-7 Vitamin K-2, 100 mcg, 120 Veg Capsules uses a patented form called MenaQ7 rather than generic menaquinone-7. This specific ingredient has published clinical trial data to support its use. It provides a 100 mcg dose, which is the standard amount for bone mineralisation. Vitamins D and K with Sea-Iodine takes a different approach by mixing 5,000 IU of Vitamin D3 with MK-7 and 1,000 mcg of iodine. This iodine comes from marine sources. It is a very high dose. One reviewer warns that this level of iodine is not for continuous daily use without medical monitoring.
MK-7 Vitamin K-2, 100 mcg, 120 Veg Capsules is the better option for adults over 40 or anyone taking high doses of D3. It scores 83.0/100 overall and 86.0/100 for value. At £24.23, it is more expensive than the competition but offers better ingredient quality at 88.0/100. Vitamins D and K with Sea-Iodine costs £14.36 and suits post-partum women or those with a confirmed vitamin D deficiency. However, its value score is much lower at 68.0/100.
The capsules from NOW Foods are small and easy to swallow. They are tasteless and odourless. This product is also a safe bet for people who need a soy-free K2 source. You must consult a doctor before using MK-7 Vitamin K-2, 100 mcg, 120 Veg Capsules if you take blood thinners like warfarin or heparin. Vitamins D and K with Sea-Iodine is often chosen by people with low sun exposure. It scores 77.0/100 for effectiveness, while MK-7 Vitamin K-2, 100 mcg, 120 Veg Capsules reaches 82.0/100.
How Do the Scores Compare?
MK-7 Vitamin K-2, 100 mcg, ...
NOW Foods
|
Vitamins D and K with Sea-I...
Life Extension
|
|
|---|---|---|
| Overall Score | 83.0 | 73.0 |
| Effectiveness |
82.0/100
Best
|
77.0/100 |
| Ingredient Quality |
88.0/100
Best
|
82.0/100 |
| Value for Money |
86.0/100
Best
|
68.0/100 |
| Side Effects |
92.0/100
Best
|
80.0/100 |
| Certifications |
60.0/100
Best
|
38.0/100 |
| Best Price | £24.72 iHerb → |
£14.49
iHerb →
Cheapest
|
| Form | None | None |
| Dose | None | None |
| Third-Party Tested | ✗ No | ✗ No |
| Reviews Analysed | 50 | 50 |
MK-7 Vitamin K-2, 100 mcg, 120 V...
Pros
- ✓Uses MenaQ7® — a patented MK-7 form with published clinical trial data, not generic menaquinone-7
- ✓100 mcg is the evidence-based daily dose for bone mineralisation and vascular calcium management
- ✓Small capsules consistently praised across reviews as tasteless, odourless, and easy to swallow
- ✓Soy-free despite K2 typically being derived from natto fermentation — clean excipient list too
Cons
- ✗Not independently third-party tested per product specs — quality relies on NOW Foods' own GMP processes
- ✗Requires medical consultation for anyone taking anticoagulants such as warfarin or heparin
Best For
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
Score Breakdown: NOW Foods MK-7 Vitamin K-2 vs Life Extension D and K with Sea-Iodine
The MenaQ7® form sets this apart from budget K2 alternatives.
What are the key differences?
Frequently Asked Questions
Which is better, NOW Foods MK-7 Vitamin K-2 or Life Extension D and K with Sea-Iodine? ▼
Is NOW Foods MK-7 Vitamin K-2 worth the price compared to Life Extension D and K with Sea-Iodine? ▼
Which has fewer side effects? ▼
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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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