Vitamin K2
Vitamin K2 (menaquinone) is a fat-soluble vitamin found naturally in fermented foods like natto, certain cheeses, and egg yolks. It plays a critical role in calcium regulation, directing calcium into bones and teeth while helping prevent its accumulation in arteries and soft tissues. The two most studied forms are MK-4 (short-acting) and MK-7 (longer half-life), with MK-7 being the more popular supplemental form.
Research Evidence
Supports bone mineral density maintenance
ModerateMay improve dental health outcomes
LimitedReduces arterial calcification markers
ModerateActivates proteins that direct calcium into bones
StrongComplements vitamin D3 for calcium metabolism
StrongExpert Evidence
53 references from 4 experts
Safety & Cautions
Side Effects
- No significant side effects at standard doses
- Rare gastrointestinal discomfort
- Potential interaction with blood-thinning medications
Vitamin K2 is generally very well tolerated, with no established upper intake level due to lack of observed toxicity. However, individuals taking warfarin or other vitamin K-dependent anticoagulants should consult their physician before supplementing, as K2 can interfere with anticoagulant dosing.
Pairs Well With
Price Comparison
From $0.04/ct
C
CarlyleBest Value
4.7
•240 ct$0.04/ct
$9.49 total
N
Nutricost
4.7
•240 ct$0.06/ct
$14.95 total
N
NOW Foods
4.7
•120 ct$0.15/ct
$17.73 total
I
InnovixLabs
4.7
•90 ct$0.30/ct
$26.95 total
T
Thorne
4.8
•60 ct$0.52/ct
$31.00 total
N
Nature Made
4.6
•30 ct$0.44/ct
$13.19 total