Three things to remember
- Vitamin K1, MK-4 and MK-7 are distinct label identities.
- Bone or vascular mechanisms do not prove that every K2 product prevents fractures or heart disease.
- Warfarin users need consistent vitamin K intake and clinician-guided changes.
Benefits and evidence limits
Adequate vitamin K is required for normal clotting. Evidence on supplements for fracture prevention is mixed, and cardiovascular-prevention benefits remain uncertain.
A phrase such as 'directs calcium to bones' simplifies a mechanism and cannot establish a guaranteed clinical effect. A product containing both D and K must be evaluated as that formulation; the existence of two relevant nutrients does not demonstrate that every user requires the combination.
Sources: Vitamin K fact sheet — NIH Office of Dietary Supplements (consumer) ↗
K1 and K2 forms
K1 is phylloquinone, also called phytonadione. K2 includes menaquinones such as MK-4 and MK-7. Leafy vegetables provide K1, while some fermented and animal foods provide menaquinones.
Record the exact form and amount. A front-label K2 claim that omits whether it is MK-4 or MK-7 leaves a useful comparison detail missing. A study of one form and regimen should not automatically be used to advertise every other form.
Sources: Vitamin K fact sheet — NIH Office of Dietary Supplements (consumer) ↗ · Vitamin K fact sheet — NIH Office of Dietary Supplements (health professional) ↗
Reference amounts and units
US/NASEM adequate intakes for adults 19 and older are 120 mcg/day for men and 90 mcg/day for women, considering total intake. These are overall vitamin K reference values, not separate established daily requirements for MK-7.
A hypothetical 0.1 mg label equals 100 mcg. Milligrams and micrograms must be aligned before comparing a high-strength preparation with a nutrition product. The same printed number with a different unit can represent a thousandfold difference.
Sources: Vitamin K fact sheet — NIH Office of Dietary Supplements (health professional) ↗
Hypothetical comparison
A ₹600 bottle has 60 capsules containing 100 mcg of a specified vitamin K form each: ₹10 per serving. A ₹450 bottle has 60 capsules, with two capsules providing 100 mcg of the same form: 30 servings at ₹15.
The lower bottle price does not produce a lower matched-serving price. If the two products use different K forms, show that difference rather than declaring them clinically interchangeable. Vitamin D in a combination should be priced and assessed as a separate component.
The warfarin interaction
Vitamin K can seriously alter the effect of warfarin. Sudden changes in intake from either food or supplements can upset anticoagulation; the goal is consistency and professional management, not automatically removing all vitamin K foods.
Orlistat and medicines that reduce fat absorption can also affect vitamin K. A product's small microgram amount does not make an interaction unimportant. A routine nutrition supplement and prescribed anticoagulation need to be considered together.
Sources: Vitamin K fact sheet — NIH Office of Dietary Supplements (consumer) ↗
What to require from the listing
A useful entry identifies form, micrograms per complete serving, servings per bottle and all co-ingredients. An MK-7 amount should not be hidden inside a total 'bone complex'.
Do not award clinical superiority for a longer ingredient list or a claim about calcium placement. The comparison can establish what a product contains and how much it costs, while clearly retaining uncertainty about fracture or cardiovascular outcomes. Medicine-related restrictions deserve a prominent place beside the product facts.
Sources: Vitamin K fact sheet — NIH Office of Dietary Supplements (consumer) ↗
Common questions
Is the vitamin K adequate intake a specific MK-7 requirement?
No. It is a reference for overall vitamin K intake, not a separately established MK-7 target.
Should a warfarin user suddenly stop eating vitamin K foods?
No. Consistent intake and clinician-guided changes are important; sudden changes can disrupt treatment.
Take the knowledge with you.
Compare the same form, active amount and intended use before comparing price. India and International listings have separate filters; some categories may have no listings in one market. Listings do not establish local stock or a need for a supplement. Shopping disclosures appear on product pages.
Sources & scope
This is a brand-independent editorial summary of the sources below, not an independent clinical review. Published reference values apply to their stated populations. Ingredient research does not verify a particular brand, batch or seller. No individual diagnosis, deficiency test or medical assessment is performed here.