Absorption & Bioavailability
When it comes to Vitamin K supplementation, form selection is one of the most consequential decisions you can make. Different chemical forms of Vitamin K vary significantly in how well your body absorbs and uses them — and MK-7 vs K1 is one of the most commonly compared pairs.
MK-7 has a higher bioavailability tier (high (S1 — best tier)) compared to K1 (moderate (S3)), meaning more of the active compound reaches the bloodstream per dose unit.
MK-7 carries a bioavailability tier of S1 (high (S1 — best tier)) and is classified as T1 Preferred in the FormulaForge formulary. K1 carries a bioavailability tier of S3 (moderate (S3)) and is classified as T3 Customer Choice.
Vitamin K2 MK-7 has a half-life of 3 days versus K1's 1-2 hours, enabling once-daily dosing with sustained activity. It preferentially activates Matrix Gla Protein to prevent arterial calcification and osteocalcin to direct calcium into bone — addressing cardiovascular and skeletal health simultaneously.
Dosing Comparison
Recommended dose ranges reflect both the potency and bioavailability of each form. Dosing data for MK-7 is being compiled, while dosing data for K1 is also being compiled.
Because forms with lower bioavailability require a larger amount to deliver equivalent absorbed nutrient, dose ranges should not be compared interchangeably between forms without accounting for these differences. Speak with your healthcare provider to determine the appropriate dose for your goals.
Side Effects & Tolerability
Both MK-7 and K1 are generally well-tolerated at recommended doses. Always consult a healthcare provider before starting any new supplement, particularly if you have existing health conditions or take medications.
Consult your healthcare provider before starting or changing a supplement regimen. These statements have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease.
Who Should Choose MK-7 vs K1?
Choose MK-7 if: bioavailability is a priority, you are focused on supporting cardiovascular function, or you want the form with the strongest formulary evidence.
Choose K1 if: you have a specific reason to prefer this form based on your healthcare provider’s guidance or personal tolerance history.
Speak with your healthcare provider for personalized guidance. The best Vitamin K form for you depends on your individual health goals, existing nutrient status, and the dose your provider recommends.
These statements are based on structure/function research and have not been evaluated by the FDA. This information is not intended to diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare provider before starting or changing a supplement regimen.