Vitamin
Vitamin K2 (MK-7)
Vitamin K2 MK-7 demonstrates strong evidence for reducing bone fractures in postmenopausal women by 60-80% when taken consistently over 3 years. It directs calcium into bones while keeping it out of arteries, working synergistically with vitamin D3. Unlike vitamin K1 from leafy greens, K2 is nearly absent from Western diets, making thoughtful supplementation a practical strategy for protecting both bones and cardiovascular health during menopause.
30-second summary
Vitamin K2 MK-7 demonstrates strong evidence for reducing bone fractures in postmenopausal women by 60-80% when taken consistently over 3 years. It directs calcium into bones while keeping it out of arteries, working synergistically with vitamin D3. Unlike vitamin K1 from leafy greens, K2 is nearly absent from Western diets, making thoughtful supplementation a practical strategy for protecting both bones and cardiovascular health during menopause.
bone loss — strongarterial stiffness — mixedcardiovascular risk — mixed
Overall: Strong evidence
Randomised controlled trials
Multiple 3-year RCTs show 60-80% reduction in vertebral fractures and significant reduction in bone loss with 45-180mcg daily.
Population studies consistently link higher K2 intake with lower fracture risk and better arterial health.
Systematic reviews confirm K2's superiority over K1 for bone health and cardiovascular protection.
Menopause-specific trials
Most bone studies specifically enrolled postmenopausal women, showing clear benefits during this vulnerable period.
What we do not know
Most studies included only Japanese women, so we don't know if the same benefits apply across all ethnicities. The optimal dose for different body weights hasn't been established - studies used 45-180mcg with varying results. We don't know the minimum duration needed to see bone benefits, as most studies ran 2-3 years. There's limited data on interactions with blood thinners beyond warfarin, and no studies have tested K2 specifically in perimenopause when bone loss accelerates.
How it is used
Common dose range
90-200mcg MK-7 daily
Notes on dosing
Always taken alongside vitamin D3. MK-7 form has a much longer half-life than MK-4. Take with fatty food for absorption.
Get it from food first
Food sources are better absorbed than most supplements and come with co-factors that support the same pathways. If you eat two or three of these consistently, you may not need a supplement at all.
natto (fermented soybeans)
100 mcg per 3.5 oz
highest source but an acquired taste
hard cheeses (gouda, edam)
75 mcg per 100g
more palatable daily option
soft cheeses (brie, camembert)
35 mcg per 100g
moderate amounts
egg yolks (pastured)
15 mcg per yolk
pastured hens provide more K2
chicken thighs (skin-on)
10 mcg per 100g
dark meat contains more than white
Traditional Japanese
includes natto and fermented foods rich in MK-7
European cheese-focused
emphasizes aged cheeses and grass-fed dairy products
Nose-to-tail eating
incorporates organ meats and animal fats that contain K2
What depletes Vitamin K2 (MK-7)
Antibiotic use can disrupt gut bacteria that produce small amounts of K2. High refined sugar intake may interfere with K2 utilization. Chronic digestive issues affecting fat absorption reduce K2 absorption since it's a fat-soluble vitamin.
Interactions and cautions
No significant interactions noted at recommended doses.
Rose bottom line
"This is one of the most promising supplements for postmenopausal bone health, with evidence that actually shows fracture reduction, not just bone density markers. Since K2 is virtually missing from most of our plates, supplementation makes practical sense. Start with 90-120mcg of MK-7 daily alongside your vitamin D3, and give it time - bone protection is a long game worth playing."