Vitamin D3 + K2 — Supplements
Synergistic vitamin combination directing calcium to bones while protecting vasculature from calcification.
Overview
The combination of vitamin D3 with vitamin K2 (menaquinone-7, MK-7) represents a physiologically synergistic pairing. Vitamin D3 enhances intestinal calcium absorption and osteocalcin production, while K2 activates osteocalcin (via carboxylation) to direct calcium into bone matrix and activates matrix Gla protein (MGP) to prevent arterial calcification. Without adequate K2, D3-enhanced calcium absorption may paradoxically increase vascular calcification risk. Multiple observational studies and RCTs support improved bone mineral density and reduced cardiovascular calcification with the combination.
Indications
- Bone mineral density optimization
- Calcium metabolism optimization
- Arterial calcification prevention
- Comprehensive skeletal health
- Vitamin D deficiency correction with safety optimization
Mechanism of Action
Vitamin D3 enhances intestinal calcium and phosphorus absorption by inducing calbindin expression
Dosing
| Compound | Dose | Frequency | Notes |
|---|---|---|---|
| Vitamin D3 + K2 (MK-7) | 5,000 IU D3 / 100 mcg K2 | Once daily with fat-containing meal | Adjust D3 dose based on 25(OH)D levels; K2 dose 100-200 mcg |
Safety & Contraindications
- K2 is safe even at high doses; no known toxicity or upper limit established
- K2 may interact with warfarin; monitor INR closely if on anticoagulants
- Vitamin D3 toxicity precautions apply (see Vitamin D3 monograph)
- Use MK-7 form of K2 (longer half-life, single daily dosing)