'Greater absorption': Australia, New Zealand regulator considering vitamin K2 use in FSMP
This is in response to an application made by Novozymes Australia Pty Ltd.
FSANZ will need to amend the Australia New Zealand Food Standards Code if it were to permit vitamin K2 for use in FSMP.
It has opened a public consultation on the matter which ends on October 11.
Vitamin K is currently permitted for use in FSMP as vitamin K1, specifically in the form of phylloquinone.
Menaquinone-7 (MK-7), on the other hand, is a form of vitamin K2.
Both vitamin K2 and K1 are fat-soluble.
FSANZ said it has assessed the safety, bioavailability, and nutritional equivalence of MK-7 as compared to phylloquinone, and considered it as a safe and bioavailable form of vitamin K.
It added that MK-7 could support normal physiological function at doses of 90µg to 360µg per day.
“Following supplementation, blood MK-7 concentrations increased compared to placebo or baseline in all studies, with greater levels of absorption compared to vitamin K1 at similar intake.
“Supplementation with MK-7 also resulted in an improvement in biomarkers for vitamin K status at doses of 90 to 360 µg/day.
“FSANZ concluded that, based on the available evidence in human studies, MK-7 is a bioavailable form of vitamin K which would be expected to support normal physiological function at doses of 90 to 360 µg/day,” said the regulator.
The vitamin is also found to be well-tolerated without causing adverse events even when taken at prolonged periods, including 360 µg/day for 12 months, 180 µg/day for three years, or 1080 µg/day three times per week for eight weeks.
“The use of MK-7 is considered safe for adults, adolescents and children.”
However, due to a lack of human studies that compare the bioavailability of MK-7 with vitamin K1 at current recommended levels, FSANZ said it cannot determine to what extent MK-7 would support essential requirements for vitamin K at the current Adequate Intake (AI), when it is the only form of vitamin K in the diet.
Still, FSANZ said that since FSMP were used under the supervision of a medical practitioner, the intake level could be modified as required.
In Australia, the AI for vitamin K is currently 70 µg/day for men and 60 µg/day for women.
Vitamin K2 is naturally occurring in food, such as cheese, fermented soybean natto, and is produced within the body by gastrointestinal bacteria. Vitamin K1, on the other hand, is present in green leafy vegetables.
Novozymes markets its menaquinone-7 under the brand name MenaquinGold, which it said could help maintain bone strength and heart health.
An example is a 2017 study published in Alternative Therapies in Health and Medicine which showed that vitamin K2 supplementation was associated with improvements in maximal cardiac output following eight weeks of supplementation.
During the randomised controlled trial involving 26 participants, the intervention group received 300mg of vitamin K2 daily between week one and four, and a lower dose at 150mg daily during the remaining weeks of the study.
The regulator vitamin K2 as MK-7 has been approved for use in FSMP in regions like the US and Europe.
Potential interactions
FSANZ pointed out that there is the potential for an interaction between vitamin K and vitamin K antagonist anticoagulant drugs. Examples of anticoagulant drugs are phenprocoumon, warfarin, and acenocoumarol.
However, it also said that individuals receiving anticoagulant therapy would be provided with advice about the risk of an interaction with vitamin K supplements.
The fact that FSMP are consumed under medical supervision would further reduce the risk of individuals taking both anticoagulant drugs and vitamin K supplements.
