WinXP running MS Virtual Machine…

I need to know if I’m running WinNT via a Virtual Machine whose host OS is WinXP, is still vunerable . With future patches for WinNT becoming harder (more expensive) to secure… the idea is to setup a WinXP machine then run these WinNT only applications in a Virtual Machine environment. My question is, will keeping the host XP machine up to date with its patches provide secure environment or does running NT, even in a VM environment, still expose all those flaws and still require patching.