Two Vitamin K2 Labels Can Match. The Molecules Don’t.

Michal Koci

Michal Koci

— 2 min read
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Short answer: a vitamin K2 label doesn’t tell you how the MK-7 was made. Fermentation and chemical synthesis can print the same words and the same dose. What differs is the share of all-trans MK-7, the form with biological activity.

Two K2 supplements can carry identical labels: vitamin K2 (MK-7), 100 µg. In one, the molecule came from bacteria. In the other, it was built from precursors with industrial solvents. Nothing on the box tells them apart.

Synthesis can leave cis isomers. These have about 1 percent of the biological activity of the all-trans form. [1] Tests that don’t separate the isomers can still count them as MK-7.

When Polish researchers tested K2 supplements, most held less all-trans MK-7 than their labels declared. One contained none. [2]

“Fermented” doesn’t settle it either. Fermented K2 can still be extracted with hexane or acetone. Solvent-free extraction is a separate decision.

The dose can also fade on the shelf. In stability tests, magnesium oxide may speed up MK-7 degradation, while calcium salts were generally more stable. [3]

To be fair, synthetic MK-7 showed no toxicity in standard animal safety tests. [4] Origin alone doesn’t decide quality. Purity and stability do.

We ferment our K2 and extract it without chemical solvents. You can’t see that from our label either. So ask any brand four questions:

  • Was the MK-7 made by fermentation or by chemical synthesis?
  • Was it extracted with solvents, and if so, which ones?
  • What share is all-trans, measured by a method that separates cis isomers? The US Pharmacopeia allows no more than 2 percent cis isomers. [3]
  • Is there stability data for the finished product, tested with the minerals in the formula?

A brand that chose its route will name it. One that didn’t will read the label back to you.

Read the full vitamin K2 breakdown on mytrime.com: the two production routes, the shortcuts a label hides, and why we chose solvent-free fermentation.

Sources
[1] Szterk A, et al. Analysis of Menaquinone-7 Content and Impurities in Oil and Non-Oil Dietary Supplements. Molecules. 2018;23(5):1056. doi:10.3390/molecules23051056
[2] Szterk A, Zmysłowski A, Bus K. Identification of cis/trans isomers of menaquinone-7 in food as exemplified by dietary supplements. Food Chemistry. 2018;243:403–409. doi:10.1016/j.foodchem.2017.10.001
[3] Orlando P, et al. Menaquinone 7 Stability of Formulations and Its Relationship with Purity Profile. Molecules. 2019;24(5):829. doi:10.3390/molecules24050829
[4] Pucaj K, et al. Safety and toxicological evaluation of a synthetic vitamin K2, menaquinone-7. Toxicology Mechanisms and Methods. 2011;21(7):520–532. doi:10.3109/15376516.2011.568983

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