Foundation Nutrients

K2+D3 Synergy

Vitamin K2 (MK-7) paired with Vitamin D3 — the essential duo that ensures calcium is deposited into bone where it belongs, not into arteries where it causes harm.

$44 60 capsules · 30-day supply

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Vitamin D3 dramatically increases intestinal calcium absorption — which is exactly what it is supposed to do. The problem is that calcium absorbed without adequate Vitamin K2 does not efficiently reach bone matrix. Instead, it circulates in the bloodstream where it can deposit into arterial walls — a primary mechanism of arterial calcification and cardiovascular risk. Vitamin K2 is the essential director of calcium transport: it activates Matrix Gla Protein (MGP) and osteocalcin, which guide calcium specifically into bone tissue and actively prevent its deposition in soft tissue.

MK-7 (menaquinone-7) is the most bioavailable and longest-acting K2 form, with a plasma half-life of 72 hours compared to 4 hours for MK-4. This means a single daily dose maintains active K2 levels throughout the day. D3 (cholecalciferol) is the natural form produced by sun exposure and is three times more potent at raising serum 25(OH)D than D2. Together, they form the only complete calcium metabolism protocol.

The Sanctum System

Where It Fits

K2+D3 Synergy anchors the bone and cardiovascular layer of the Foundation Nutrients tier. It works synergistically with Magnesium Glycinate (magnesium is required to convert Vitamin D to its active form and to support calcium regulation) and Collagen Matrix (bone matrix requires both collagen and calcium in the correct architectural relationship).

Daily Stack · Foundation Nutrients

Built For

Who It's For

Everyone over 35, anyone with limited sun exposure (office workers, northern latitudes, protective clothing), anyone supplementing calcium, and anyone concerned about both bone density and cardiovascular health. The K2+D3 combination is arguably the most universally necessary pairing in the foundation stack.

You have limited daily sun exposure (office, northern climate, or seasonal)
You are supplementing with calcium and want to direct it to bone, not arteries
You are managing bone density or osteoporosis risk proactively
You want to support both cardiovascular health and skeletal integrity simultaneously

Formulation

What's Inside

Compound	Amount Per Serving	Role
Vitamin D3 (Cholecalciferol)	5,000 IU	Natural sun-equivalent D3; increases intestinal calcium absorption and immune modulation
Vitamin K2 (MK-7, from Natto)	180mcg	Longest-acting K2 form (72-hr half-life); activates MGP and osteocalcin for calcium direction to bone
Magnesium (as Magnesium Oxide)	50mg	Cofactor for Vitamin D hydroxylation (activation); included to support D3 conversion

Serving size: 1 capsule. 60 capsules per bottle. Manufactured in the USA in a cGMP-certified facility. Third-party tested for potency and purity.

†These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Questions

Frequently Asked

Why does K2 matter when taking D3? +

D3 increases calcium absorption. K2 directs where that calcium goes. Without K2, absorbed calcium circulates freely and can deposit in arterial walls — a mechanism of cardiovascular calcification. K2 activates proteins that specifically direct calcium into bone and away from soft tissue. The two must be taken together.

Why MK-7 and not MK-4? +

MK-7 has a plasma half-life of 72 hours — a single daily dose maintains active levels throughout the day. MK-4 is cleared in 4 hours and requires multiple daily doses. MK-7 also has more published clinical evidence for bone density and cardiovascular K2 activity.

Is 5,000 IU of D3 safe? +

5,000 IU is appropriate for restoring deficiency (which affects 42% of adults) and maintaining optimal serum 25(OH)D levels of 50-80 ng/mL. Toxicity requires sustained doses above 40,000 IU/day. If you are uncertain, get your 25(OH)D tested — it's a standard blood panel item.

Should I take it with Magnesium Glycinate? +

Yes. Magnesium is required for the enzymatic activation of Vitamin D (the hydroxylation steps that convert D3 to its active 1,25-OH form). Without adequate magnesium, D3 supplementation is partially wasted. We include a small magnesium dose in the formula, but full Magnesium Glycinate supplementation is recommended.

Can I take it with food? +

Vitamin D3 and K2 are fat-soluble vitamins — they absorb significantly better when taken with a meal containing dietary fat. Take K2+D3 Synergy with your fattiest meal of the day.

Community

Reviews

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