In most cases, you would want the SharePoint navigation to be security trimmed based on a user’s access to the site. If they have no access then you wouldn’t want them to see the link. In some cases however, you would like users to see the items and get an access denied message with the ability to request access. Once the publishing features have been activated within a site collection, this setting can easily be configured from the UI.
From Site Settings select the Site Collection Navigation Settings:
Remove the option for security trimming:
When a user doesn’t have access they will see an access denied link, with the option to request access.
You can configure the email address that the request is sent to in the Manage Permissions page.
This will remove the security trimming from both the Global Navigation (top bar) and the Current Navigation (Quick Launch).