Home Ingredients UniK2® (Vitamin K2 as MK-7 from Natto — IFF)
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UniK2® (Vitamin K2 as MK-7 from Natto — IFF)

Evidence Level
Limited
1 Clinical Trial
4 Documented Benefits
2/5 Evidence Score

UniK2® is a natural vitamin K2 in the menaquinone-7 (MK-7) form, derived from natto, the fermented soy food. Vitamin K2 is used by the body to activate proteins involved in handling calcium. The two reports cited on this page come from three years of MK-7 (not UniK2) in healthy postmenopausal women, one on bone and one on artery stiffness, a marker rather than heart events. No trial of the UniK2 brand itself is cited.

Studied Dose MK-7 is commonly sold at 45 to 180 mcg a day. Both reports cited on this page used 180 mcg a day for three years; lower doses were not tested in them.
Active Compound Vitamin K2 as menaquinone-7 (MK-7) from natto fermentation.

Benefits

Bone strength

In a three year randomized, placebo controlled trial in 244 healthy postmenopausal women, 180 mcg of MK-7 a day improved vitamin K status and slowed the age related decline in bone mineral content and density at the lumbar spine and femoral neck. There was no significant effect at the total hip. The trial tested generic MK-7 rather than the UniK2 brand, and the authors cautioned that the results may not carry over to men or children.

Supported by Trial 1

Matrix Gla protein, the proposed link

Vitamin K2 activates matrix Gla protein, which in laboratory work helps limit calcium deposits in artery walls. In the three year arterial stiffness trial cited here, the inactive form of this protein in blood fell by 50% compared with placebo. That is a blood marker and a proposed explanation, not proof of less calcium in artery walls, and the trial measured vessel stiffness rather than heart attacks or strokes.

Supported by Trial 1

How MK-7 works with calcium

MK-7 activates osteocalcin, the protein that binds calcium into the bone matrix. Whether supplementing changes where calcium ends up in the body was not tested directly; the reports cited here measured bone density and content, and artery stiffness.

Supported by Trial 1

Lower arterial stiffness in postmenopausal women (MK-7, not UniK2)

Tested MK-7 sold under another brand (MenaQ7), not UniK2, at 180 mcg a day. In a placebo controlled trial in 244 healthy postmenopausal women, three years of MK-7 significantly lowered carotid-femoral pulse wave velocity and a stiffness index, with extra gains in women whose arteries were stiffer at the start. Inflammation and endothelial markers did not change. It is a single trial in women only, measuring stiffness, not heart events.

Supported by Trial 1

Mechanism of action

1

Osteocalcin activation

MK-7 carboxylates (activates) osteocalcin, the protein that binds calcium into the bone matrix.

2

Matrix Gla protein activation

MK-7 activates matrix Gla protein, which in laboratory research limits calcium deposition in artery walls. In the cited arterial stiffness trial, the inactive form of this protein in blood fell with MK-7, but that is a marker, not a direct measure of calcium in artery walls.

Clinical trials

1
Generic MK-7 and Bone Loss: 3 Year RCT
PubMed

Three year randomized, placebo controlled trial giving 180 mcg a day of generic menaquinone-7 to 244 healthy postmenopausal women. The product tested was not UniK2. The study was funded by NattoPharma, maker of the MenaQ7 brand, and the arterial stiffness report of a trial with the same size, dose and length names MenaQ7 as the product. (Knapen et al. 2013, Osteoporosis International)

244 healthy postmenopausal women; men and children were not studied.

MK-7 improved vitamin K status and slowed the age related loss of bone mineral content and density at the lumbar spine and femoral neck compared with placebo. There was no significant effect at the total hip.

Side effects and drug interactions

Common Potential side effects

Reported as well tolerated in the three year trial cited here, which enrolled only healthy postmenopausal women; tolerability was not tested in men or children.
Vitamin K2 interferes with warfarin-type blood thinners; do not use without medical supervision.
Mild digestive upset is occasionally reported.

Important Drug interactions

Warfarin and other vitamin-K-antagonists — directly opposes these blood thinners; medical supervision required.
No other drug interactions are described on this page; ask your pharmacist about your own medicines before starting.
Tell your doctor if you take anticoagulants.

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Frequently asked questions about UniK2® (Vitamin K2 as MK-7 from Natto — IFF)

What is UniK2?

UniK2® is a natural vitamin K2 in the menaquinone-7 (MK-7) form, derived from natto, the fermented soy food. Vitamin K2 is used by the body to activate proteins involved in handling calcium.

What is UniK2 used for?

UniK2 is researched primarily for Bone Health and Cardiovascular. In a three year randomized, placebo controlled trial in 244 healthy postmenopausal women, 180 mcg of MK-7 a day improved vitamin K status and slowed the age related decline in bone mineral content and density at the lumbar spine and femoral…

What is the recommended dosage of UniK2?

The clinically studied dose is MK-7 is commonly sold at 45 to 180 mcg a day. Both reports cited on this page used 180 mcg a day for three years; lower doses were not tested in them. Always follow the product label and check with a healthcare provider for personal advice.

Is UniK2 safe, and does it have side effects?

Side effects and cautions reported for UniK2 include: Reported as well tolerated in the three year trial cited here, which enrolled only healthy postmenopausal women; tolerability was not tested in men or children. Vitamin K2 interferes with warfarin-type blood thinners; do not use without medical supervision. It may also interact with some medications. UniK2 is not right for everyone, so check with a healthcare provider first if you are pregnant or breastfeeding, have a medical condition, or take prescription medication.

Does UniK2 interact with any medications?

Possible interactions include: Warfarin and other vitamin-K-antagonists — directly opposes these blood thinners; medical supervision required. No other drug interactions are described on this page; ask your pharmacist about your own medicines before starting. If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for UniK2?

NutraSmarts rates the evidence for UniK2 as Limited (2 out of 5). It is backed by 1 study summary and 2 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(2 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Knapen MH, Drummen NE, Smit E, et al. Three-year low-dose menaquinone-7 supplementation helps decrease bone loss in healthy postmenopausal women. Osteoporos Int. 2013;24(9):2499-507..PubMedUsed to support: Randomized, placebo controlled three year trial of generic MK-7 (the same nutrient used in UniK2) in 244 healthy postmenopausal women. The paper names no brand, so this is not UniK2 specific evidence, and no UniK2 trial is cited on this page. Bone endpoints only, with no significant effect at the total hip.
  2. Knapen MH, Braam LA, Drummen NE, Bekers O, Hoeks AP, Vermeer C. Menaquinone-7 supplementation improves arterial stiffness in healthy postmenopausal women. A double-blind randomised clinical trial. Thromb Haemost. 2015;113(5):1135-44..PubMedUsed to support: Double-blind, placebo controlled trial of MK-7 sold as MenaQ7 (a different brand, not UniK2) at 180 mcg a day for three years in 244 healthy postmenopausal women. Carotid-femoral pulse wave velocity and the stiffness index beta fell significantly on MK-7, with further local gains in women with stiffer arteries at baseline, and inactive matrix Gla protein fell 50% versus placebo. Inflammation and endothelial markers did not change. Its size, dose and length match the bone trial cited here, so it is likely the same study.