Food/vitamins for tendons?

So I know that there are certain foods or vitamins you can take to keep certain parts of your body healthy. You can eat vegetables for eyes, drink calcium for bones, etc. Is there any certain substance that helps strengthen tendons? I have problems with the tendons in my pinkies and wrists, and my doctor said it was from overuse of tendons, so I was trying to figure out a way to strengthen them. Thanks for any help you can give!