Which worms are most nutritious?

Question
I have two eastern painted turtles about 2 years old.  My vet recommended that I feed them worms but wasn't specific and I know some are more nutritious than others.  So what are the most nutritious types of worms to give to an aquatic turtle?  There are so many types to choose from and some much more difficult to get a hold of.  I want to make sure I'm giving them a good one.

And to follow rule (1), they're painted turtles in a 50 gallon tank, rock substrate, 3 spot lights - 1 UVA/UVB (72 degrees), 1 heat light for day (86 degrees) and 1 heat lamp for night (no light and 74 degrees).  The UVA/UVB and heat lamp are on separate sides of tank with separate basking areas.  Water is heated to 72 degrees.  Both turtles were sick when I bought them from the best store and have been on antibiotics for over a month and recovering from bacterial infections.  Water is kept very clean with a canister filter and they're fed in a separate container.  Both now eat once a day and are in better health.

Answer
You didn't follow the rules completely. There is a lot missing here. You mention vet, but are these turtles still currently under vet care for the issue? If so, what was the illness and treatment? How long ago did you see the vet. Antibiotics that long term creates problems. Also, this information is going to differ from what I might say if I had a complete history.  

The most nutritious worms would probably be earthworms or night crawlers. These are low in fat, sodium, phosphorous, and chitin, and high in protein. They are such a good food, I wish my other herps would eat them too. They also require variation in the diet, and you should also offer things like snails, slugs, crickets, brine shrimp, bloodworms are a favorite, as well as anacharis, duckweed and various forms of algae and sometimes regular veggies. This depends though on if they have some condition which the vet is recommending the worms, and you providing more complete information.