I saw an interesting post in regards to Afghanistan asking whether it was more important for us to push for education or health. You can easily see the issue. People can't learn if they're sick, and people have a hard time not being sick when stupid.
From a foreign policy perspective, it's certainly a sticky issue. The organic growth of increasing health, education, and social stability that the west went through is something that would take multiple generations. We could wait that long, but we might not need to.
I think that it's a false dichotomy. Obviously, health must be covered first, but only for the students. If we can create an island of health in an otherwise destitute area, as long as violence doesn't take that away, we can then focus on the education of the healthy. A very small degree of health must be ensured before education becomes paramount, but after that point, education is without doubt the most important element in society building.