C# API, not seeing all properties

When I query the API for a user and get their profile back, I am not able to see all the available properties that can be seen in the profile through the web interface.

So for example we have a Leave Reason Code and Leave Reason and neither of those are available using the API.

It seems most other properties are there. Is there something that must be done through the web interface in order for the API to be able to see all the properties?