What kind of interaction is it?

Synergy: a documented combination effect that is stronger or more useful than either substance taken alone.

Is this interaction backed by published research?

Yes. NutriStack lists 4 citation rows for the Vitamin D3 + Vitamin K2 pair, each linking to PubMed by PMID where available. Full sourcing methodology at https://nutristackapp.com/methodology/interactions.

Interaction databaseSupplement × SupplementReviewed May 2026

Vitamin D3 and Vitamin K2, a synergy.

Q: Can I take Vitamin D3 and Vitamin K2 together?

Yes. The combination of Vitamin D3 and Vitamin K2 produces a measurable benefit. Vitamin D3 increases calcium absorption, while K2 activates osteocalcin and matrix GLA protein to direct calcium into bones and away from arteries.

Q: How does this affect a NutriStack Stack Score?

+2 to your Stack Score per scored synergy row.

Vitamin D3 increases calcium absorption, while K2 activates osteocalcin and matrix GLA protein to direct calcium into bones and away from arteries.

4 primary source citations. Moderate evidence. Last verified May 30, 2026.

Open the interaction checker →Read the methodology

One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
Same shape as the other 1,729 pairs in the public database.

Sourcing standards·Evidence tiers

From the interaction database

What the row says.

Every entry follows the same shape: what is happening, the mechanism, the recommendation, and the primary literature.

At a glance

Substances: Vitamin D3 and Vitamin K2
Pair type: Synergy
Evidence (highest tier): Moderate
Source citations: 4 sources
Stack Score effect: +2 to your Stack Score (per scored synergy row).
Scope: Supplement × Supplement
Last verified: May 30, 2026

Synergy · Moderate evidence

Synergy

What is happening. Vitamin D3 increases calcium absorption, while K2 activates osteocalcin and matrix GLA protein to direct calcium into bones and away from arteries.

Mechanism. D3 upregulates calcium absorption; K2 activates calcium-binding proteins (osteocalcin, MGP) that shuttle calcium to bone matrix and prevent arterial calcification. Note: 2023 meta-analysis of 14 RCTs found vitamin K supplementation did NOT significantly prevent vascular calcification.

Recommendation. Take together. K2 (MK-7 100-200mcg) is recommended whenever supplementing D3 above 2000 IU.

Sources (4)

Masterjohn C. Vitamin D toxicity redefined. Med Hypotheses. 2007 PMID 17141962
Kidd PM. Vitamins D and K as pleiotropic nutrients. J Orthomol Med. 2010
Chang MC, Choo YJ. Effects of Whey Protein, Leucine, and Vitamin D Supplementation in Patients with Sarcopenia: A Systematic Review and Meta-Analysis.. Nutrients. 2023. PMID 36771225
Kuang X, Liu C, Guo X, Li K, Deng Q, Li D. The combination effect of vitamin K and vitamin D on human bone quality: a meta-analysis of randomized controlled trials. Food & Function. 2020. PMID 32219282

Stack Score

How this pair moves the number.

Effect on the composite score

If both Vitamin D3 and Vitamin K2 are in the same stack, this pair applies +2 to your Stack Score (per scored synergy row).

The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.

Check your full routine

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