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Thorne Vitamin K

The most comprehensive vitamin K supplement available — combining K1, K2 as MK-4 (5 mg), and K2 as MK-7 (MenaQ7, 90 mcg) in a single capsule that covers coagulation, bone mineralisation, and arterial calcium regulation through three distinct forms working across different tissue types and timeframes.

Vitamin K is the nutrient almost nobody thinks about and almost everybody needs more of. It is essential for two processes your body cannot function safely without: blood clotting and calcium trafficking. Without adequate K1, your blood cannot coagulate properly — cuts bleed longer, bruises form more easily, and internal bleeding risk increases. Without adequate K2, the calcium your body absorbs from food and vitamin D supplementation has no direction — it may deposit in bone matrix where it strengthens your skeleton, or it may accumulate in arterial walls where it stiffens blood vessels and accelerates cardiovascular disease. The difference between these two outcomes is determined almost entirely by whether enough activated vitamin K-dependent proteins are present to route calcium correctly.

Most people supplementing vitamin D without K2 are increasing calcium absorption without ensuring it reaches the right destination. The vitamin K market is fragmented and confusing. K1 supplements support coagulation but do not meaningfully activate the bone and vascular proteins that K2 governs. MK-7 supplements provide long-acting K2 with a 72-hour half-life but at doses too low to match the tissue-level activity of MK-4. MK-4 supplements deliver the form most concentrated in bone, brain, and reproductive tissue but clear the bloodstream within hours, requiring higher doses or multiple daily servings.

Most products contain one form at one dose and call it complete. You buy K1 for clotting, or MK-7 for convenience, or MK-4 for potency — and whichever you choose, the other pathways remain unsupported.

Thorne Vitamin K eliminates the compromise by combining all three forms in a single capsule at clinically meaningful doses. Vitamin K1 (1 mg) provides the substrate for hepatic production of clotting factors II, VII, IX, and X — the coagulation cascade your body activates every time tissue is damaged. Vitamin K2 as MK-4 (5 mg) is the form most concentrated in human tissue — particularly bone, brain, pancreas, and arteries — where it activates osteocalcin (directing calcium into bone) and matrix Gla protein (preventing calcium deposition in blood vessels). At 5 mg, this is a substantially higher MK-4 dose than most competitors offer. Vitamin K2 as MK-7 (90 mcg as MenaQ7) provides the long-acting form with a 72-hour half-life that maintains baseline K2 activity between doses — MenaQ7 is the most clinically validated MK-7 on the market, with published research on bone density and arterial flexibility. The three forms together create continuous, multi-tissue vitamin K coverage that no single form can achieve.

Thorne is NSF Certified for Sport, third-party tested through four rounds of quality verification. No gluten, dairy, soy, artificial colours, or preservatives. 60 capsules per bottle — a one-to-two-month supply.

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Take one capsule one to two times daily, or as recommended by your healthcare professional. Can be taken with or without food, though a meal containing dietary fat may enhance absorption. Best paired with vitamin D3 supplementation — vitamin D increases calcium absorption, and vitamin K directs that calcium to bone rather than arterial tissue. Do not use if taking anticoagulant medications (warfarin, acenocoumarol, phenprocoumon) — vitamin K directly opposes the mechanism of these drugs and will reduce their effectiveness. If you are on any anticoagulant therapy, consult your prescribing doctor before supplementing. If pregnant, consult your healthcare professional before use. Store in a cool, dry place. Keep out of reach of children. 60 capsules per bottle. Three forms, one capsule, complete calcium logic — because the vitamin that decides where calcium goes deserves as much attention as the vitamin that puts it there.

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