NSTK · 01.2026Independent supplement reference
NutriStack
Edition 1.0Updated August 1, 2026

Supplement × Supplement·Evidence index

Vitamin D3 and Vitamin K2 MK-4: what the published research says

PubMed indexes 3 records that name Vitamin D3 and Vitamin K2 MK-4 together, either in the title or in an interaction, co-administration, or pharmacokinetic context. Each one is listed below with its study design and, where the abstract states one, the authors’ own conclusion, quoted and linked. This page reports that literature. It does not tell you whether to combine them.

Read this first

An evidence index, not guidance.

Every statement below is attributed to a named, dated, linked source.

This page lists published research relevant to Vitamin D3 and Vitamin K2 MK-4. It deliberately does not state whether the combination is safe, whether it interacts, in which direction, at what dose, or how far apart to take them.

The research

3 studies naming Vitamin D3 and Vitamin K2 MK-4.

Strongest relevance first: papers naming both substances in the title, then human trials and systematic reviews.

Simultaneous Determination of Vitamins D3 (Calcitriol, Cholecalciferol) and K2 (Menaquinone-4 and Menaquinone-7) in Dietary Supplements by UHPLC.

Molecules (Basel, Switzerland) · 2021 · PMID 34834074

“The validation results indicated that the method had reasonable linearity (R2 ≥ 0.9990), good recovery (>82%), satisfactory intra-day precision (≤1.9%) and inter-day precision (≤3.5%), and high selectivity and specificity. The validated UHPLC method was demonstrated to be precise, accurate, and robust for the simultaneous determination of vitamins D3 (CT and CHL) and K2 (MK-4 and MK-7) in dietary supplements.”

Becze et al. · From the abstract

Names both Vitamin D3 and Vitamin K2 MK-4 in its title.

Clinical Pharmacokinetics of Active Vitamin D3 and its derivatives, and Vitamin K2(Menatetrenone).

Clinical calcium · 2016 · PMID 27777388

Human subjects

“Active vitamin D3 and its derivatives have their own feature of pharmacokinetics, due to differences in binding affinity for carrier protein such as vitamin D binding protein and in metabolism. Menatetrenone is easily absorbed from intestine, and distribute to bone higher than other natural vitamin K homologues.”

Tsugawa · From the abstract

Names both Vitamin D3 and Vitamin K2 MK-4 in its title.

Limitations

What this evidence cannot tell you.

Search-based evidence indexes have real limits, and it is worth being explicit about them:

NutriStack

Track what you actually take.

NutriStack is a free iPhone app for organising a supplement routine: what you take, when, and what the published record says about it. Its exploratory interaction checker covers Vitamin D3, Vitamin K2 MK-4, and several hundred other substances.

The checker is a research and organisation tool, not a clinical decision aid, and its per-pair assessments are excluded from search until they pass claim-level review.

NutriStack is an informational and organizational tool, not a medical service, and not a substitute for professional advice. Always consult a qualified healthcare professional before starting, stopping, or changing any supplement or medication.