While collagen is not a complete protein, it does contain 57% of these tree non-essential amino acids that contribute to the health of skin, hair, and joints. The three amino acids are proline, glycine, and hydroxyproline. Well, actually, hydroxyproline is produced in the body from proline with the help of vitamin C. Without vitamin C, proline will not change into hydroxyproline and collagen production will be limited. This is vital. eat an orange, or take a low dose, 250 mg, vitamn C with complex: citrus bioflavonoids, hesperidin, and rutin.