GLOSSARY

Menaquinone-7 (MK-7) is a menaquinone with seven isoprene units, present in some fermented foods, especially natto.

Leafy greens are important K1 sources; some animal and fermented foods contain menaquinones, with amounts varying by food and processing. Gut production also occurs but cannot guarantee full coverage for everyone. A sports diet should retain diverse vegetables and other sources rather than assign a universal fixed amount to any food simply labelled fermented.

Vitamin K includes phylloquinone and the menaquinone family; K2 is not one molecule. An MK number denotes side-chain units rather than dose or guaranteed potency. MK-4 can be produced in the body from suitable precursors and MK-7 occurs in some fermented foods. K2 alone does not establish origin, amount or product superiority.

Vitamin K supports carboxylation of certain proteins involved in clotting and some bone and tissue processes. A K-dependent protein's presence in a pathway does not prove that extra supplementation strengthens it without limit. Bone or performance claims need intake context and human outcome evidence, rather than inference solely from a protein's biological role.