MDA on NPA's is slowly being replaced by DA at a lot of EASA member-state airports, sometimes resulting in slightly higher minima's.
In some cases, 50' makes the difference of becoming visual or doing a G/A. This is why I am not a fan of VNAV NPA approaches combined with an MDA in marginal weather. Use the V/S and put the MDA in the MCP. Keep slightly low in order to ensure level flight at the Decision Point. (Decision Point is the point where on a normal ILS, you would end up at minima considering a standard glide angle of 3°). If no contact, go around. (and NO there is NO requirement to fly level up to the MDA, this is a big misunderstanding by some collegues).
HOWEVER, and this I must emphasise: FOLLOW your COMPANY SOP. This is a personal note and in my present company VNAV NPA's are not done.