Vitamin K2 with D3 by Ortho Molecular Products

If your Vitamin D, 25-Hydroxy is low or in the lower end of normal and you get little sun, this vitamin K2 with D3 fits. The 5,000 IU D3 here is a higher daily dose, useful for darker-skinned adults at northern latitudes, indoor workers, and post-menopausal women focused on bone density. It also makes sense if you want K2 for calcium handling and your diet is light on fermented foods like natto. If your vitamin D level is already solid, this is maintenance-to-high, so re-test in 8–12 weeks and consider stepping down.

D3 raises calcium absorption from the gut and helps keep parathyroid hormone (the signal that pulls calcium from bone) in check. K2 in the MK-7 form activates osteocalcin (a bone protein that locks calcium into the bone matrix) and matrix Gla protein (a protein that keeps calcium out of arteries). MK-7 has a longer half-life than K1 or MK-4, so it keeps these proteins active through the day. In practice, the pair directs absorbed calcium toward bone and away from soft tissues.

Take one capsule daily with a meal that contains fat for best absorption. Consistency matters more than time of day. This is often enough to raise Vitamin D, 25-Hydroxy within 8–12 weeks; recheck labs and adjust. If you’re already on separate D3, avoid doubling up. You don’t need to add calcium unless your dietary intake is low, and excess calcium supplements can be counterproductive.

Skip K2 if you use warfarin (Coumadin), a vitamin K–antagonist blood thinner, unless your prescriber is closely managing your dose. Direct oral anticoagulants like apixaban and rivaroxaban don’t interact with vitamin K. High-dose D3 is not ideal with a history of high blood calcium, recurrent kidney stones, sarcoidosis, or untreated overactive parathyroid. Fat-blocking drugs (orlistat) and bile acid binders (cholestyramine) reduce absorption; separate by several hours.