The Device.Media object has a few handy methods. You can use the IsCameraAvailable() method to determine if supported on the device.
There are also other methods to determine if taking photo is supported on the device. Another method is TakePhoto() which is launched to native device you eye for the user to take a photo.
var photoFile = await Device.Media.TakePhoto();
Device.Media also provide similar methods for picking a safe photo for the device albums.
var photoFile = await Device.Media.PickPhoto();