Compound · vitamin-d3-k2
T1Supplement

Vitamin D3 + K2 (MK-7)

Vitamin D3 (cholecalciferol) is hydroxylated in the liver to 25(OH)D then in the kidney to active 1,25(OH)2D (calcitriol), which binds the vitamin D receptor (VDR) present in virtually every cell type. VDR activation modulates over 1,000 genes involved in immune function, calcium homeostasis, muscle protein synthesis, and inflammatory regulation. Vitamin K2 (menaquinone-7) activates matrix GLA protein (MGP) and osteocalcin via gamma-carboxylation. MGP inhibits vascular calcification; osteocalcin directs calcium into bone. The D3+K2 combination ensures calcium mobilized by D3 is deposited in bone rather than arterial walls.

Half-life
~15 days (25(OH)D); ~72 hours (MK-7)
Bioavailability
~80% (D3 oral with fat); ~20-30% (MK-7 oral)
Route
oral
Evidence tier
T1 — Multiple RCTs
Optimization pillars
cellular-health · muscle · recovery · anti-aging
References
3 peer-reviewed
Dose ranges

Three tiers ordered by aggressiveness. Tier chips on every OPTIMIZE intervention let you filter the catalog by your evidence tolerance.

conservative
2000 IU D3 + 100mcg K2/day
Maintenance for adequate levels
moderate
4000–5000 IU D3 + 200mcg K2/day
Optimization to 50-70 ng/mL 25(OH)D
aggressive
5000–10000 IU D3 + 200mcg K2/day
Repletion for severe deficiency (monitor levels)
Monitoring
  • vitamin-d
  • lipid-panel
Contraindications
  • hypercalcemia
  • granulomatous-disease
  • warfarin-use-for-k2
References
  • PMID:28768407Vitamin D supplementation to prevent acute respiratory tract infectionsBMJ, 2017
  • PMID:26770129The role of vitamin K in soft-tissue calcificationAdv Nutr, 2016
  • PMID:31405892Vitamin D deficiency and supplementation in athletesNutrients, 2019
Notes

Vitamin D3 is the single most important supplement for anyone not living near the equator. 42% of US adults are deficient. The VDR modulates over 1,000 genes. Deficiency impairs immune function, muscle protein synthesis, insulin sensitivity, and bone metabolism simultaneously. The K2 pairing is not optional — D3 increases calcium absorption, and without K2 to activate MGP, that calcium can deposit in arterial walls instead of bone. MK-7 is the preferred K2 form due to its 72-hour half-life versus MK-4 at 1-2 hours. Target 50-70 ng/mL 25(OH)D. Test levels. Dose accordingly. Take with fat.

This is not medical advice

Discuss with a licensed clinician before starting, stopping, or changing any compound. This page documents what the research literature describes — it is not a prescription.

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