[NTG-context] How to adjust inter item vertical space

I want to fit a page with an itemized group of items. The normal vertical spacing is to large and the [packed] doesn't give enough seperation between items. I should think that there's a simple way to adjust this with \setupitemize command or even with \startitemize. Is there? I did try \setupitemize[inbetween=\whitespace[medium]] , but it didn't do much or seemed to be applied to every line and not just between item and 'medium' doesn't give much information. Is there some way to specify a measurement to seperate between items such as .5cm for example? Thanks