Sun exposure is the best for vitamin D3!
The optimal dosage of K2 would be around 30 – 40mcg for every 1000iu of vitamin D3 ingested.
Black, Ryker. Underground Life Extension Handbook: An A – Z of Anti-Aging Compounds And How To Use Them Effectively: Supplements – Drugs – Peptides – Hormones – Experimental Compounds . Ryker Black Publications. Kindle Edition.