D3 (cholecalciferol) raises 25-OH-D 87% more than D2 (ergocalciferol). MK-7 has 72h half-life vs MK-4 1-2h. Only two combinations work in humans at useful doses.
Human endogenous form · synthesized in skin
Best for
Ideal use: 99% of cases. Any serious D supplementation uses D3.
Advantages
Raises 25-OH-D 87% more than D2 (Tripkovic 2012 meta). 25-day half-life. Form used in ALL cardinal RCTs (VITAL · DO-HEALTH · Manson 2022).
Disadvantages
Sheep lanolin origin · not default vegan. Lichen-based D3 (vegan) versions exist but less available in Spain.
From Bacillus subtilis natto · 72h half-life
Best for
Ideal use: mandatory combo with D3 >2,000 IU/day. Gold standard.
Advantages
90-180 µg/day dose covers 24h with single intake. Form used in AVADEC trial. Activates arterial MGP + bone osteocalcin.
Disadvantages
Expensive vs MK-4. Unstable in some formats (temperature-sensitive gummies). Some warfarin patients require adjustment.
Synthetic · 1-2h half-life
Best for
Ideal use: only if your doctor specifically prescribes for active osteoporosis. For general use, MK-7.
Advantages
Japanese therapeutic dose for osteoporosis was 45 mg/day (yes, mg not µg) · showed bone efficacy in Japan RCTs.
Disadvantages
Short half-life requires 3 daily intakes. Effective dose (45 mg) is 250× MK-7 · more expensive in practice. Less CV data.
Ideal use: 99% of cases. Any serious D supplementation uses D3.
Ideal use: mandatory combo with D3 >2,000 IU/day. Gold standard.
Ideal use: only if your doctor specifically prescribes for active osteoporosis. For general use, MK-7.
D3 (cholecalciferol) raises 25-OH-D 87% more than D2 (ergocalciferol). MK-7 has 72h half-life vs MK-4 1-2h. Only two combinations work in humans at useful doses.