The role of menaquinones (vitamin K₂) in human health 

This comprehensive review from 2013 offers insights into the health benefits of menaquinones as compared to phylloquinone. Citing biochemical as well as intervention studies demonstrating beneficial effects on bone parameters and cardiovascular health (coronary calcifications). Particularly noting that studies with benefits required very high doses of MK-4 (generally 45 mg) which are above what can be obtained from a typical diet. 

References:

Beulens JW, Booth SL, van den Heuvel EG, Stoecklin E, Baka A, Vermeer C. The role of menaquinones (vitamin K₂) in human health. Br J Nutr. 2013 Oct;110(8):1357-68. doi: 10.1017/S0007114513001013. Epub 2013 Apr 16. PMID: 23590754.