Search peptides — top sellers first
Search peptides — top sellers first
Search peptides — top sellers first
Cholecalciferol D3 with K2 as MK-7 for bone mineralization, immune function, and calcium handling.
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Vitamin D3 + K2 · mg
Frequently bought together
Researchers usually add these to complete the protocol.
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Certificate of analysis
We don't publish a brand-wide spec sheet and call it a “COA.” The certificate you receive references the actual lot number stamped on your vial — with the raw chromatograms attached.
Vantage Analytical
Independent analytical lab
Certificate of Analysis
RESULT · PASS
Analytical results
HPLC Chromatogram
Purity
Know your compound
Vitamin D3 (cholecalciferol) is the form your skin makes from sunlight and the form your liver converts most readily toward the active hormone. K2 as MK-7 (menaquinone-7) is a separate fat-soluble nutrient that activates two calcium-binding proteins: osteocalcin, which anchors calcium in bone, and matrix Gla protein, which keeps it out of arteries. D3 raises how much calcium you absorb from the gut; K2 governs where that calcium ends up. Both absorb poorly without dietary fat, which is why the pairing is discussed together.
In postmenopausal women with osteoporosis, combined D3 and K2 has been studied for its effect on lumbar spine bone mineral density over 24 months. Vitamin D status is also one of the better-characterized nutritional markers, and supplementation reliably raises serum 25(OH)D. The mechanism for pairing the two is tidy; the long-term outcome data is thinner, and we will say so until it changes.
For research use only — not for human or veterinary use.
The research
The published findings behind this compound — the headline numbers, in plain terms, each cited to source. Preclinical results are directional (animal / in-vitro) and shown for context, not as therapeutic claims.
Published research on the reference compound class. Provided for scientific context only — not a claim about the product supplied.
In postmenopausal women with osteoporosis, combining vitamin D3 and K2 was studied for its effect on lumbar spine bone density over about 24 months, with the combination trending toward better maintained density than comparison.
Directional finding — relative heights, not exact magnitudes.
In women undergoing leuprolide therapy, adding vitamin K2 plus 1,25-dihydroxyvitamin D3 was associated with less bone loss than the therapy alone.
Directional finding — relative heights, not exact magnitudes.
In cultured human bone-lining cells, vitamin K2 enhanced the mineralization driven by active vitamin D3 — a lab clue to why the two are paired.
Directional cell-culture finding — relative heights, not exact magnitudes.
Mechanism
D3 and K2 as MK-7 are studied to act through three distinct routes in calcium handling and bone metabolism.
D3 converts toward the active hormone that is involved in how much dietary calcium the gut absorbs.
K2 as MK-7 activates osteocalcin, a protein that participates in anchoring calcium within bone tissue.
K2 also activates matrix Gla protein, which is involved in keeping calcium out of soft tissue and arteries.
For research use only. Mechanisms described reflect published preclinical and clinical literature.
The process
Synthesized
Produced under controlled manufacturing with documented, repeatable processes.
HPLC purity
An independent lab reports the exact purity of every lot — a number, never a 'passes'.
Mass-spec identity
Molecular weight confirms the exact sequence is what the label says.
COA published
The certificate is posted to the open library, by lot, before the vial ships.
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FAQ
Common questions about Vitamin D3 + K2
The COA guarantee
Have any lot independently re-tested. If the results don't match the published certificate, we refund the order in full — no returns, no questions.
Order with coverThird-party tested
An independent, accredited lab — no commercial interest in the result.
A COA on every lot
A lot-specific certificate ships with each vial, archived by batch.
Test it yourself → refund
Re-test any batch at any lab. A mismatch is a full refund.
