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Vitamin K2 (MK-7) — Frequently Asked Questions

This content is for informational purposes only and does not constitute medical advice. Consult your healthcare provider before starting any supplement. Full disclaimer

Frequently Asked Questions

What is the difference between vitamin K1 and K2?

Vitamin K1 (phylloquinone) is found in green leafy vegetables and primarily supports blood clotting. Vitamin K2 (menaquinone) is found in fermented foods and animal products and primarily supports calcium metabolism — directing calcium into bones and away from arteries. They activate different proteins: K1 mainly activates clotting factors in the liver, while K2 activates osteocalcin (bones) and MGP (arteries) throughout the body.

Should I take K2 with vitamin D?

Yes, combining K2 with vitamin D is recommended, especially at higher D3 doses. Vitamin D increases calcium absorption from the gut, and K2 ensures that calcium goes to your bones rather than accumulating in arteries. Without adequate K2, increased calcium absorption from vitamin D could theoretically contribute to arterial calcification. A general guideline is 100 mcg MK-7 per 1,000-2,000 IU vitamin D3.

Is MK-7 or MK-4 the better form of K2?

MK-7 is generally preferred for daily supplementation because of its long half-life (72 hours) allowing once-daily dosing and consistent blood levels. MK-4 has a very short half-life (1-2 hours) requiring multiple doses daily, but has more direct tissue-level research, particularly for bone health at pharmacological doses (45 mg/day) in Japan. For most people, MK-7 at 100-200 mcg daily is the practical choice.

Full Vitamin K2 (MK-7) Guide

References

  1. (). Three-year low-dose menaquinone-7 supplementation helps decrease bone loss in healthy postmenopausal women. Osteoporosis International. DOI
  2. (). Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: the Rotterdam Study. Journal of Nutrition. DOI
  3. (). Vitamin K-containing dietary supplements: comparison of synthetic vitamin K1 and natto-derived menaquinone-7. Blood. DOI