The human body does not make its own lysine or vitamin C. Lysine and vitamin C are both important for joint health and hormone production. Both are easily destroyed by heat, making a review of cooking methods essential. Foods rich in vitamin C should be eaten raw whenever possible or tossed in at the end of preparation of a recipe. Stir-fry, grill or broil foods rich in vitamin C rather than roasting or toasting them.

Enzyme and Hormone Production

Lysine is one of nine essential amino acids that the body needs to make enzymes and hormones. Essential amino acids are ones that the body does not make on its own. One of the enzymes that lysine helps produce -- carnitine -- converts fatty acids into energy and helps to lower cholesterol. Adequate levels of lysine regulate the body's response to stress, while deficiencies raise stress levels and lower disease resistance, according a 2004 study published in the "Proceedings of the National Academy of Sciences."

Vitamin C helps the body produce thyroid hormone and metabolize folic acid, tyrosine and tryptophan. Vitamin C helps regulate stress by releasing norepinephrine and epinephrine.

Calcium Absorption

Lysine helps the body retain and absorb calcium. Roasting or toasting destroys lysine quickly, so eat nuts raw and stir-fry or broil meat instead of roasting. Calcium intake can be challenging for vegans and vegetarians, but plant-based products such as spirulina and soybeans help balance lysine intake.

Collagen Formation and Scurvy Prevention

Both lysine and vitamin C assist in collagen formation, which helps the body build connective tissues such as skin, tendons and cartilage. Collagen helps the body repair blood vessels, heal bruises and mend bone fractures.

Vitamin C prevents scurvy, a disruption of collagen manufacturing that causes lack of energy, tooth decay, gum inflammation and bleeding problems. The human body needs at least 10 milligrams of vitamin C per day to avoid scurvy.

Sources of Vitamin C and Lysine

Good sources of vitamin C include citrus fruit, sweet and hot peppers, potatoes, spinach, parsley, cabbage, broccoli, Brussels sprouts, rose hips, black currants and other berries, tomatoes, horseradish and watercress. Good sources of lysine include red meat, pork, poultry, Parmesan cheese, cod, sardines, nuts, eggs, soybeans, spirulina and fenugreek seed, according to the University of Maryland Medical Center.