Hi Lins_Saving_Gr ace, vitamin C is good for a lot of things, even years and years ago when I had my Danes it was given to prevent the paws from spreading, both with mastiffs aswell as danes you want the tight feet. I give yougurt too, I have to admit not on a regular basis but it is good for their stomachs though, especially the ones with bellies that tend to get upset.
What you said about that a good breeder address the hip/elbow issue before they leave the nest. hmmmm not sure if I understand what you mean. I am with you that they should have all their health certificates, and at the very leaset you should have full certs for both parents and better yet. for grandparents and elbow and hip should be done on as many of their breedings as possible. But as for x-ray the puppy itself, I guess you could do it just for a first check when they are about a year old but really no reason, because it is not an accurate reading. On I believe all giants the hip and elbow x-rays can not be recorded until they are at least 24 months. Having good readings on the parents is extremely important and checking up on their breeding in the past how they are with their joints, but unfortunately that is no guaranti. Once in a blue moon you can get a bad hip or elbow even from the soundest line.
Another thing that can effect hips or elbows, is how they grow up. Do they grow too fast, are they constantly on slippery floors, are they playing very hard and maybe fall bad well with a little bit of bad luck that can make a difference when the day comes to x-ray, so me for one am really really keeping my fingers crossed and even with the best lines, I have a hard time breathing until I have the final reading in my hand.