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The Best Vitamin D3 and K2 Supplements

Updated By the HealthWorld editorial teamHow we pick

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Top picks at a glance

  1. 1
    Nature Made Vitamin D3 2000 IU

    Best D3 to pair with K2

    Nature Made Vitamin D3 2000 IU

    Vitamin D3 2000 IU · Form Softgel

  2. 2
    Thorne Vitamin D-5,000

    Best higher-dose D3 (doctor-guided)

    Thorne Vitamin D-5,000

    Vitamin D3 5,000 IU · Form Capsule

Vitamin K2 is often paired with D3 because both play roles in how the body uses calcium, and MK-7 is the form most combination products use. We don't currently list a combined D3 + K2 product, so our picks are trusted D3-only supplements; if you want K2 too, use the checklist below to choose an MK-7 product. If you take warfarin or another blood thinner, talk to your doctor before taking vitamin K.

Our picks

  1. Nature Made Vitamin D3 2000 IU

    #1Best D3 to pair with K2

    Nature Made Vitamin D3 2000 IU

    USP Verified vitamin D3 at 2000 IU, one small softgel a day. It contains no K2, so add a separate MK-7 supplement if you and your doctor decide you need it.

    Vitamin D3 2000 IUForm SoftgelAmazon Full facts →
  2. Thorne Vitamin D-5,000

    #2Best higher-dose D3 (doctor-guided)

    Thorne Vitamin D-5,000

    5,000 IU of vitamin D3 in one small capsule. It's D3 only and above the standard adult upper limit, so use it with your doctor's guidance.

    Vitamin D3 5,000 IUForm CapsuleAmazon Full facts →
Amazon's live top 100 in Vitamins

What to look for

K2 as MK-7
MK-7 stays in the body longer than the MK-4 form, which is why most D3 + K2 products use it. K2 doses are listed in micrograms (mcg), so check the label.
A sensible D3 dose
Combination products vary widely in their D3 dose. Stay within the 4,000 IU daily upper limit for adults unless your doctor recommends more.
Blood thinners
Vitamin K can interfere with warfarin. If you take any blood thinner, don't start K2 without talking to your doctor.
Combo or separate
A combined softgel is convenient. Buying D3 and K2 separately lets you adjust each dose, which helps if your doctor wants you on a specific vitamin D dose.
Third-party testing
Look for USP Verified, NSF or similar marks, which confirm the label matches the contents.

Frequently asked questions

Does vitamin D3 need K2?

Not necessarily. Vitamin D3 works on its own, and most people get some vitamin K from foods such as leafy greens, fermented foods and cheese. The idea behind pairing them is that K2 helps direct calcium to bones, but research on whether the combination improves outcomes is still limited. Ask your doctor, especially if you take higher doses of D3.

Is D3 with K2 better than D3 alone?

For most people, there isn't strong evidence that adding K2 makes D3 work better for bone health. It may be worth discussing with your doctor if you take higher doses of D3 or eat few vitamin K foods. Anyone on warfarin or other blood thinners should talk to their doctor first, since vitamin K affects how these drugs work.

When should you take vitamin D3 and K2, morning or night?

Either is fine. Both are fat-soluble, so take them with a meal that contains some fat. Many people take them with breakfast or lunch simply to make it a habit.

Can you take vitamin D with magnesium?

Yes. They're often taken together, and some D3 + K2 products also add magnesium. Keep supplemental magnesium within 350 mg a day unless your doctor advises otherwise.

Sources