Vitamin K

50–90% of US adults are deficient in vitamin K; it is important for essential body functions.

Why It Matters for Longevity

50–90% of US adults are deficient in vitamin K; it is important for essential body functions. Vitamin K is an essential cofactor for blood clotting proteins (factors II, VII, IX, X) and for the carboxylation of osteocalcin, the bone matrix protein that binds calcium. Deficiency leads to impaired coagulation and reduced bone mineralization.. Longo recommends ensuring adequate vitamin K intake via a multivitamin every 2–3 days and through green leafy vegetables. Plant foods (kale, spinach, broccoli) provide vitamin K1 (phylloquinone); fermented foods and some animal products provide K2 (menaquinones), which has greater affinity for vascular and bone tissues.. PMID 24841044: Vitamin K2 (MK-7) supplementation significantly improved bone mineral density and reduced vertebral fracture risk in postmenopausal women, supporting the book's emphasis on K as a bone-health nutrient. (PubMed) PMID 19179058: Prospective cohort data show higher dietary K2 intake is inversely associated with coronary calcification and cardiovascular mortality, extending the book's focus beyond bone to vascular longevity. (PubMed)

How to Use It

Pairs well with kale, spinach, broccoli. Use as a nutrient in your daily meals according to the Longevity Diet guidelines.

What to Pair It With

Ingredient	Why	Tradition
kale	See synergies	Top K1 source: ~817 mcg per 100 g raw
spinach	See synergies	K1: ~483 mcg per 100 g raw
broccoli	See synergies	K1: ~102 mcg per 100 g raw
olive oil	See synergies	Fat-soluble vitamin; dietary fat enhances K1 absorption from vegetables
natto	See synergies	Highest known food source of K2 MK-7: ~1000 mcg per 100 g

Synergies

Vitamin D (synergy): Vitamin D promotes calcium absorption and osteocalcin synthesis; vitamin K2 activates osteocalcin via carboxylation, directing calcium into bone rather than soft tissues. Co-supplementation is widely recommended for bone and vascular health. - Calcium (synergy): K2 activates matrix Gla protein (MGP) and osteocalcin, which guide calcium into bone and prevent arterial calcification; without adequate K, calcium supplementation may increase vascular calcification risk. - Olive Oil (complement): Dietary fat is required for absorption of fat-soluble vitamin K1 from vegetables; drizzling olive oil on leafy greens significantly increases phylloquinone bioavailability.

Flavor Profile

Category: supplement/nutrient.

The Science

PubMed: PMID 24841044: Vitamin K2 (MK-7) supplementation significantly improved bone mineral density and reduced vertebral fracture risk in postmenopausal women, supporting the book's emphasis on K as a bone-health nutrient. - PubMed: PMID 19179058: Prospective cohort data show higher dietary K2 intake is inversely associated with coronary calcification and cardiovascular mortality, extending the book's focus beyond bone to vascular longevity. - PubMed: PMID 28025257: Review confirms widespread subclinical K deficiency in Western populations (consistent with the 50–90% figure cited by Longo) and links inadequate status to accelerated vascular calcification and frailty in aging. - Examine.com: Examine notes that K1 and K2 have distinct tissue distributions; K2 MK-7 has a longer half-life and superior bone/vascular effects at lower doses, suggesting K2 supplementation is preferable for longevity applications. - Book claim (high confidence): 50–90% of US adults are deficient in vitamin K; it is important for essential body functions. - Book claim (high confidence): Longo recommends ensuring adequate vitamin K intake via a multivitamin every 2–3 days and through green leafy vegetables

Key Nutrients

Nutrient	Per 100g	Notes
Phylloquinone (K1)	Varies by source; kale ~817 mcg, spinach ~483 mcg	K1 absorption from vegetables is enhanced by co-consumption of dietary fat; cooking increases bioavailability compared to raw.
Menaquinone-7 (K2 MK-7)	Natto ~1000 mcg; other fermented foods ~10–50 mcg	MK-7 has a plasma half-life of ~72 hours vs ~1 hour for K1; better sustained activation of vascular and bone K-dependent proteins.