A complete safety, timing, and dosage guide for combining Magnesium (Citrate, Glycinate, Oxide, Threonate) with Vitamin K (K1, K2) — including how the two supplements interact, the best time of day to take each, and which populations should be careful.
Yes, you can safely take vitamin K and magnesium together — no known interaction, and they combine well for bone and heart health.
Vitamin K and magnesium together are safe and well-tolerated, with no negative interaction affecting absorption or effectiveness. Vitamin K + magnesium may actually support bone and cardiovascular health, as magnesium is a cofactor for vitamin K-dependent protein activation. Taking them at the same time is practical and does not require dose adjustments or special timing.
Vitamin K (K1 and K2) is a fat-soluble vitamin absorbed in the small intestine along with dietary lipids and packaged into chylomicrons, so its absorption depends on the presence of fat in the meal. Magnesium, by contrast, is a divalent cation absorbed through distinct paracellular and active transcellular pathways in the small and large intestine, meaning it does not share any transport proteins with vitamin K. Because they use different absorption routes, there is no competition between them, and neither changes the other's plasma concentration or tissue uptake. In fact, magnesium supports the activity of vitamin D, which in turn promotes vitamin K-dependent carboxylation of osteocalcin in bone — a complementary, rather than interfering, relationship. No cytochrome P450 involvement or other metabolic conflict exists between these two nutrients, so they can be taken together safely.
If you are taking both, I recommend taking vitamin K with a meal that includes healthy fat — such as breakfast with eggs or lunch with olive oil — and taking magnesium at the same meal or with an evening snack, whichever is easiest for you. There is no need to space them apart; taking them together in the same meal maximizes convenience and does not reduce absorption. For bone health, aim for vitamin K2 as MK-7 at 90–120 mcg daily and magnesium glycinate or citrate providing 200–300 mg elemental magnesium. If you miss a dose, simply resume at your next planned meal and do not double up. If you take a combined D3+K2 product, you can still add magnesium at the same time without any concern.
For magnesium, citrate and glycinate forms are well absorbed and generally gentle on the stomach, while magnesium oxide is poorly absorbed and often causes loose stools — so choose citrate or glycinate if daily use is intended. Magnesium threonate is also well absorbed and may have cognitive benefits, but its interaction with vitamin K is no different from any other form. For vitamin K, K1 (phylloquinone) from leafy greens and K2 (menaquinone, especially MK-7) from fermented foods both behave similarly with magnesium, though K2 has a longer half-life and better tissue retention. None of the magnesium forms interfere with vitamin K absorption, and vitamin K's fat solubility remains the only factor to consider when timing your dose.
These two are routinely found in bone health formulations alongside vitamin D3 and calcium, and in cardiovascular support stacks with CoQ10 and omega-3 fatty acids. They also appear in some prenatal and general wellness combinations, though often as separate capsules rather than a single pill.
Yes, you can take them together at the same meal. I recommend taking vitamin K with food that contains fat to help absorption, and magnesium is fine with or without food, so taking both at breakfast or dinner works well.
Yes, it is safe to take this combination daily within the recommended doses. I have no concerns about long-term use, and I suggest choosing a well-absorbed magnesium form like glycinate or citrate and keeping your vitamin K intake consistent to maintain steady levels.
You do not need to wait any time. I take them together with a fat-containing meal, and there is no evidence that spacing them improves absorption or reduces any side effects.
No, they do not compete. Vitamin K is a fat-soluble vitamin absorbed through lipid pathways, while magnesium is a mineral absorbed through separate ion transporters, so taking them together does not reduce the absorption of either one.
Most people can take them safely together. I tell my patients on warfarin to be consistent with vitamin K intake and to inform their doctor before adding magnesium, and those with advanced kidney disease or a history of kidney stones should also check with their healthcare provider before supplementing magnesium.
Take vitamin K with a meal that includes fat, since it is fat-soluble and needs dietary lipids for proper absorption. Magnesium can be taken on an empty stomach, but I recommend taking it with food to avoid stomach upset, so taking both at a main meal is the simplest approach.
Reviewed by Caroline M. on March 25, 2026 for accuracy against the sources listed above. This page is educational and is not a substitute for professional medical advice.
The matrix has 86 supplements and 7310 pairwise interactions. Click any cell to see the full breakdown.