I used to be thought that human milk was too low in iron, now we know that the iron is so bio-available that human milk doesn't need to be high enough in iron to be adequate, it may be the same with apparently "too low " levels of Vit. K in human milk. Keep inmind that colostrum is richer in Vit. K than mature milk, too.
This site says that the right enzymes for the body to absorb Vit. K orally don't appear in babies until 3 months old, and that the highest risk of hemorage is in the first 3 days, before the oral dose could be well absorbed in any case, which makes me think the jab is a better bet. Also reviews the research that provoked controversary about the jab.
I'm not sure that mother nature really did get it right on this one, though, low Vit. K levels may have had other benefits before or during birth that were worth taking the risk of hemorage afterwards, but as humans we can choose to not have the risk trade-off.
For my own babies I got oral doses, or no dose at all...But not at all sure if what I did was best. I'm thru having babies but if I had another I think maybe I'd get the jab, get it over & done with.