NutriStack
Vitamin D3 and Vitamin K2 MK-4, a synergy.
Vitamin D3 increases calcium absorption, while K2 activates osteocalcin and matrix GLA protein to direct calcium into bones and away from arteries.
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.
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 MK-4
- Pair type
- Synergy
- Evidence (highest tier)
- Moderate
- Source citations
- 3 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 (3)
- 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
Stack Score
How this pair moves the number.
Effect on the composite score
If both Vitamin D3 and Vitamin K2 MK-4 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.
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