Restrict Which Users Can Enter Data In List Form in SharePoint Foundation 2013

Question

Is there a way to restrict which users can enter data in particular fields in a list item entry form?
We are using a SharePoint Foundation 2013 list and calendar to manage vacation time. We need to restrict non-supervisor users users from entering a value in a certain field in the vacation request form.
Here is how the system works now:
1. Employees complete the vacation request form (which creates a list item)
2. An email is sent to their supervisor to either approve or decline the request
3. Approved requests are automatically entered onto the vacation calendar
We have restricted the list so that only supervisors can edit items (the pending vacation requests). The problem is that all users can mark their own requests as approved when they fill out the request form in the first place. Is there a way to restrict
which users can enter data in particular fields on a list item entry form?

Answer 1

Thanks for the suggestion. We ended up 1) hiding the approval column and 2) creating a second list, workflow, etc. The user no longer sees the approval column when filling out the form. Requests are now submitted to list A. Workflow #1 copies the request
to List B, then deletes the item from List A. Once the request is added to List B, Workflow #2 emails the user that the request has been received and emails the supervisor that a request needs to be approved. Only supervisors have editing permissions on List
B. Approved requests are automatically added to the vacation calendar (the calendar view of List B).
We found the following site to be helpful in learning how to hide the list column:
http://community.bamboosolutions.com/blogs/bambooteamblog/archive/2013/06/03/how-to-hide-a-sharepoint-list-column-from-a-list-form.aspx