Tendons and ligaments also need vitamin C, a nutrient found in many vegetables and fruits, because both tissues contain large amounts of collagen. Vitamin C plays an essential role in new collagen production, and a vitamin C deficiency can weaken your tendons and ligaments by preventing collagen synthesis. Men should try to consume at least 90 milligrams of vitamin C daily, and most women need 75 milligrams, according to Linus Pauling Institute.