Along with everyone else I agree that being able to have a relationship with and to refer to a Registered Dietitian is important.
Like any other health care professional it is important to vet the Dietitian you would like to refer to. Check local better business bureaus, chambers of commerce, local/regional Registered Dietitian sites, speak to other trainers.
For the RD’s and Holistic Nutritionists I work with, besides meeting with them prior to adding to my referral network, I have attended any workshops or community presentations they have done and even ask (if they are interested and can do) to trade a nutrition consult or two for training services. What better way to see how they do what they do?
And finally, I have introduced my new health practitioner network members by offering a group workshop to my clients (who can also bring a friend) so they can also get a “taste” of the professional I will be using in my referral network.
It all seems a bit time-consuming, but it is the process I have liked to go through and makes me comfortable.