When to capitalize a registered profession?

I understand the rule to capitalize a profession (i.e. job title) when it is precedes a name, as in President John Doe... but what if we are talking about titles in general. I am working on a document that discusses when to request a referral to Registered Dietitian, Occupational Therapist or Speech Language Pathologist. Should these all be lower case, or capitalized?

Example: Feeding therapists are often Speech Language Pathologists, Occupational Therapists or Registered Dietitians and can be referred to using [blank] form.

Actually Choster is incorrect. These titles are still common nouns. Just because they say “certified or professional or licensed” does not make them proper. Unless they include the name of the licensure, they remain common. I’m a technical writer with more than 16 years of experience and an undergrad and grad degree in the subject matter. People always want to over capitalize everything. It’s annoying.