Vitamin D3 + K2 (MK-7): How to Read the Label

Vitamin D3 and vitamin K2 are often sold together, sometimes with calcium. The labels can look confusing: micrograms and International Units, “MK-7”, amounts per capsule and per day. Here is how to read each line.

Vitamin D3: micrograms and IU

Vitamin D is listed in micrograms (mcg), and many labels also show International Units (IU). The conversion is simple: 1 mcg = 40 IU. So 125 mcg is the same as 5,000 IU, and 25 mcg is 1,000 IU.

“D3” means cholecalciferol, the form of vitamin D your skin makes from sunlight. In fall and winter, when days are shorter and people spend more time indoors, many people pay closer attention to vitamin D in their routine.

Vitamin K2: what “MK-7” means

Vitamin K comes in two main groups: K1 (phylloquinone, found in leafy greens) and K2 (menaquinones). K2 has several forms, labeled MK-4, MK-7 and so on. MK-7 is the form most often found in D3 + K2 supplements, and it is listed in micrograms.

Important: vitamin K can interact with anticoagulant (blood-thinning) medications such as warfarin. If you take one, talk to your healthcare professional before using any product that contains vitamin K.

Calcium: check the % Daily Value

Calcium is listed in milligrams (mg) with a % Daily Value. The Daily Value for adults is 1,300 mg, which includes calcium from food. A supplement usually supplies only part of that, and the rest comes from your diet.

Per capsule vs. per day

This is the step most people skip. Some labels list amounts per capsule and then tell you to take more than one capsule a day. Multiply the per-capsule amount by the number of capsules in the directions to know your daily total.

Count all your sources

Vitamin D and calcium also appear in multivitamins, fortified foods and other supplements. Add them up. The NIH Office of Dietary Supplements lists an upper intake level for vitamin D of 100 mcg (4,000 IU) per day for most adults unless a healthcare professional advises otherwise, so follow the label directions and review your total intake with your healthcare professional, especially if you take several products.

An example: Boneflux™

Boneflux™ Vitamin D3 + K2 + Calcium lists, per veggie capsule:

• Vitamin D3: 125 mcg (5,000 IU)
• Vitamin K2 (MK-7): 100 mcg
• Calcium: 210 mg
• BioPerine® black pepper extract: 5 mg

The suggested use on the label is one capsule twice a day, 20–30 minutes before a meal with an 8 oz. glass of water, or as directed by your healthcare professional. One bottle of 60 capsules lasts 30 days at that use. Do not exceed the recommended dose.

Before you choose

• Convert mcg to IU (× 40) if you are comparing products.
• Check the form of K2 (MK-7 or MK-4).
• Multiply per-capsule amounts by your daily capsules.
• Consult a healthcare professional before use if you are pregnant, nursing, under 18, taking medication (especially blood thinners) or managing a medical condition.

For quality documentation, visit our Certificate of Analysis section.

See the full Boneflux™ label and details.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.