Generate Random Matrix in Matlab

Is there any way in Matlab to generate a 5000 x 1000 matrix of random numbers in which:

MM = betarnd(A,B,1,1000);

but A and B are vectors (1 x 5000). I get the following error message:

??? Error using ==> betarnd at 29
Size information is inconsistent.

I want to avoid a loop like the following one:

for ii = 1 : 1000
  MM(:,ii) = betarnd(A,B); 
end

Thanks!