<p>On one of the nozzles on my printer, the filament comes out at a 45 degree angle.  It seems that this causes problems with adhesion to the bed and overall quality.</p>

<ul>
<li>What caused this problem? </li>
<li>How do I fix it? </li>
<li>How do I prevent it from
happening in the future?</li>
</ul>

If you're extruding into the air, it's actually quite normal for the filament to come out in seemingly random directions. This shouldn't cause problems because the filament should always be getting squished onto the bed/layer underneath (or during bridging, getting stretched). The way the filament comes out in free air doesn't reflect how it behaves during printing.
If you are experiencing troubles then perhaps the nozzle is clogged with a small piece of debris (or, unlikely) the nozzle is actually damaged. There's little you can do to prevent that apart from using high quality filament and being careful not to damage the nozzle.