Vitamins
Evidence: strong_human
Vitamin K2 (menaquinone-7) activates vitamin K-dependent proteins via gamma-carboxylation of glutamic acid residues. Key targets: osteocalcin (directs calcium into bone matrix), matrix Gla protein (MGP, inhibits arterial calcification), Gas6 (cell signaling, neuroprotection), and protein S (anticoagulant). MK-7 has a long half-life (~72 hours vs 1-2 hours for K1) enabling consistent carboxylation activity with once-daily dosing. It works synergistically with Vitamin D3 to regulate calcium metabolism — D3 increases calcium absorption while K2 directs its deposition.
Standard: 100-200 mcg MK-7 daily
Loading: 200-400 mcg/day for first 3 months (especially with high-dose D3 supplementation)
Maintenance: 100-200 mcg/day
Administration: oral
Timing: With fat-containing meal alongside Vitamin D3.
Duration: ongoing (mandatory co-supplement with Vitamin D3)
Possibly the most underappreciated vitamin. The vitamin D-K2 pairing should be considered inseparable for any practitioner. Warfarin interaction is the single most critical clinical concern — screen every client. For clients on warfarin, discuss with their prescriber about switching to a DOAC, which would allow K2 supplementation. MK-4 (45mg, the Japanese osteoporosis dose) works differently than MK-7 — it has tissue-specific effects and short half-life. Both forms have merit but MK-7 is standard for general health optimization.
MK-7 (from natto fermentation) preferred over MK-4 for longer half-life and lower dosing requirements. All-trans MK-7 is the bioactive form — some cheap products contain cis-MK-7 (inactive). Brands: Thorne Vitamin D/K2 Liquid, Carlson Vitamin K2, Life Extension Super K (contains K1 + MK-4 + MK-7).
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