Research statusCatalogued record, not clinically approved.
Citation presence and an automated evidence check are not medical review.
This pair has not completed NutriStack's standalone publication gate. Attached sources may mention one or both substances without establishing the stored interaction type, direction, severity, dose, management advice, or combined safety. The page is excluded from search indexing and must not be used to start, stop, or change treatment.
From the databaseWhat the row says.
Every entry follows the same shape: what is happening, the mechanism, and the recommendation.
Scope
Supplement × Supplement
Last updated
July 13, 2026
SynergyModerate evidence
What is happening. Vitamin D supports calcium absorption, while vitamin K is required for normal vitamin-K-dependent proteins involved in bone and clotting biology. Some studies examine combined D/K supplementation, but K2 is not universally required for every D3 user.
Mechanism. Vitamin D and vitamin K participate in related calcium and bone pathways, but clinical benefit from routine pairing varies by population and outcome.
Why it matters. Do not imply D3 is unsafe or ineffective without K2.
Recommendation. Consider K2 only when it fits diet, medications, and clinician guidance. People using warfarin or similar anticoagulants should not change vitamin K intake without prescriber guidance.
How to manage it. Individualize based on diet, anticoagulant use, dose, and clinical goals.
Direction. The effect runs both ways: each one influences the other.
Stack Score
How it moves the number.
Effect on the composite score
No numeric score interpretation is published for this unreviewed pair record.
Stack Score is a NutriStack product heuristic, not a clinical risk or benefit grade. An unreviewed database label must not be treated as a safety or benefit signal. The algorithm is documented at /methodology/stack-score.
SourcesSources, by evidence tier.
Sources attached to the record. Some support an ingredient or mechanism rather than a study of the exact pair; PMIDs link to PubMed where available.
FAQCommon Vitamin D3 + Vitamin K2 questions.
Plain-language answers drawn from the interaction record on this page.
Can I take Vitamin D3 and Vitamin K2 together?
NutriStack catalogs Vitamin D3 and Vitamin K2 as a potential synergy. Confidence depends on whether the sources below study the exact combination. Vitamin D supports calcium absorption, while vitamin K is required for normal vitamin-K-dependent proteins involved in bone and clotting biology. Some studies examine combined D/K supplementation, but K2 is not universally required for every D3 user.
What kind of interaction is it?
Potential synergy: the stored record proposes a useful combination effect, but the sources and evidence caveats determine whether the exact pair has been tested.
How does this affect a NutriStack Stack Score?
No numeric score interpretation is published for this pair because its stored label has not completed source-level clinical review.
What do the cited sources establish?
NutriStack lists 4 source records with this Vitamin D3 + Vitamin K2 entry. A source may support an ingredient, mechanism, or safety concern without testing the exact pair, so citation presence alone does not prove the visible verdict. Full sourcing methodology is at https://nutristackapp.com/methodology/interactions.
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