Supplement·Interactions·Reviewed June 9, 2026
Vitamin K2 interactions.
Vitamin K2 has 26 documented interactions in the NutriStack database: 1 to avoid or watch closely, 6 that need timing or caution, and 19 that work synergistically. The full list, with what each pairing does, is below.
Vitamin K2 at a glance.
A quick, data-grounded summary. The full table is below.
Vitamin K2 has 26 documented interactions in the NutriStack database: 1 to avoid or watch closely, 6 that need timing or caution, and 19 that work synergistically. The full list, with what each pairing does, is below.
Everything that interacts with vitamin k2.
Every supplement and medication in the NutriStack database with a documented interaction with this substance, highest-severity first. Open any pair for the mechanism and sources.
| Substance | Interaction | What happens |
|---|---|---|
| Warfarin | Conflict | Vitamin K2 directly opposes warfarin's mechanism of action. Warfarin works by inhibiting vitamin K-dependent clotting factor synthesis, so... details → |
| Ampicillin | Caution | Broad-spectrum antibiotics such as ampicillin can suppress vitamin K-producing gut bacteria, occasionally lowering vitamin K status. This is most... |
| Cefixime | Caution | Broad-spectrum antibiotics including cephalosporins can suppress vitamin K-producing gut flora during prolonged or repeated courses, which may... |
| Ceftriaxone | Caution | Ceftriaxone suppresses vitamin K-producing gut bacteria and has been associated with hypoprothrombinemia and bleeding, particularly in malnourished... details → |
| Cephalexin | Caution | Broad-spectrum antibiotics including cephalosporins suppress vitamin K-producing gut bacteria, which can lower endogenous vitamin K2 (menaquinone)... details → |
| Dicloxacillin | Caution | Broad-spectrum and beta-lactam antibiotics can disrupt gut flora that synthesize vitamin K, theoretically reducing endogenous vitamin K... |
| Vitamin E | Caution | High-dose vitamin E may reduce K2-dependent protein carboxylation, potentially affecting both bone and cardiovascular K2 benefits. |
| Alendronate | Synergy | Alendronate plus vitamin K2 produces greater suppression of undercarboxylated osteocalcin and modestly better bone outcomes than alendronate alone... details → |
| Calcitriol | Synergy | Vitamin K2 is sometimes used to support calcium-handling proteins, but it does not prevent calcitriol-induced hypercalcemia. |
| Calcium | Synergy | K2 activates osteocalcin to direct calcium to bones and matrix GLA protein to prevent arterial calcification. Essential when supplementing calcium. details → |
| Calcium Alpha-Ketoglutarate | Synergy | Vitamin K2 activates osteocalcin and matrix Gla protein, helping incorporate calcium into bone and limit vascular calcium deposition, which... |
| Evening Primrose Oil | Synergy | Evening Primrose Oil provides a fat-containing carrier that can improve absorption of fat-soluble compounds like Vitamin K2. |
| Fish Oil | Synergy | K2 (MK-7) is fat-soluble and absorption increases with dietary fat. Fish oil provides an excellent fat vehicle. details → |
| Fish Oil Triple Strength | Synergy | K2 (MK-7) is fat-soluble and absorption increases with dietary fat. Fish oil provides an excellent fat vehicle. details → |
| Flaxseed Oil | Synergy | Flaxseed Oil provides a fat-containing carrier that can improve absorption of fat-soluble compounds like Vitamin K2. |
| Krill Oil | Synergy | K2 (MK-7) is fat-soluble and absorption increases with dietary fat. Fish oil provides an excellent fat vehicle. details → |
| Magnesium Glycinate | Synergy | Magnesium supports the vitamin D activation and calcium handling that vitamin K2 then directs into bone, complementing K2's role in mineralization. |
| MCT Oil | Synergy | MCT Oil provides a fat-containing carrier that can improve absorption of fat-soluble compounds like Vitamin K2. |
| Medroxyprogesterone | Synergy | Vitamin K2 complements calcium and vitamin D for bone protection during DMPA use by activating osteocalcin and matrix Gla protein. Although direct... |
| Ox Bile | Synergy | Ox bile can enhance absorption of Vitamin K2 by promoting the bile-salt micelle formation that menaquinone requires to cross the gut wall. This... |
| Raloxifene | Synergy | Vitamin K2 is sometimes used for bone matrix protein carboxylation and may overlap with bone-health goals. |
| Risedronate | Synergy | Vitamin K2 complements bisphosphonate therapy by activating osteocalcin, the matrix protein that binds calcium into bone. Combining vitamin K2 with... details → |
| Strontium | Synergy | Vitamin K2 supports directing calcium into bone and away from arteries, complementing strontium's bone-building action within a bone-health regimen. |
| Vitamin A | Synergy | Vitamins A and K2 contribute to bone and calcium handling alongside vitamin D, supporting balanced mineralization at nutritional intakes. |
| Vitamin D3 | Synergy | Vitamin D3 increases calcium absorption, while K2 activates osteocalcin and matrix GLA protein to direct calcium into bones and away from arteries. details → |
| Vitamin K1 | Synergy | K1 primarily supports coagulation while K2 (MK-7) directs calcium to bones. Complementary roles in vitamin K metabolism. details → |
The full vitamin k2 profile.
Benefits, dosing by goal, forms, and the cited evidence for this supplement.
Common vitamin k2 questions.
Quick answers drawn from the table above.
What interacts with Vitamin K2?
In the NutriStack database, Vitamin K2 has 26 documented interactions with other supplements and medications. The most notable include Warfarin, Ampicillin, Cefixime, Ceftriaxone, and Cephalexin.
What should you not take with Vitamin K2?
Vitamin K2 is flagged against 1 substance in the database, including Warfarin. Review these with a clinician before combining, especially alongside prescription medications.
What works well with Vitamin K2?
Vitamin K2 pairs synergistically with Alendronate, Calcitriol, Calcium, Calcium Alpha-Ketoglutarate, and Evening Primrose Oil in the NutriStack database. Synergy still depends on dose and timing; open any pair for the detail.
Can you take Vitamin K2 with Warfarin?
NutriStack classifies the Vitamin K2 and Warfarin pairing as conflict: Vitamin K2 directly opposes warfarin's mechanism of action. Warfarin works by inhibiting vitamin K-dependent clotting factor synthesis, so supplemental vitamin K2 can... Avoid vitamin K2 supplementation while on warfarin unless directed and closely monitored by your prescriber. If K2 is deemed necessary, maintain a...
Check your whole stack
See how vitamin k2 fits your routine.
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