I have been doing some research on the subject of longevity, and came accross an amino acid called lysine. It is needed to form protein in the body.
Lysine is known to boost the immune system by effectively helping suppress the herpes simplex virus, which manifests in symptoms like mouth blisters and cold sores.
Consequently, lysine supplements are now widely recommended for the treatment of herpes. Daily lysine supplements of 500mg were also found to increase the blood level of ferritin (an iron-binding protein ) in women with iron-deficiency anemia.
Lysine is also needed to form collagen, the subskin and connective tissues, and is essential for calcium absorption.

Since it is lacking in grains, nuts, and seeds, lysine supplements can help prevent calcium deficiencies particularly among strict vegetarians and the elderly.
Lysine also combines with methionine, to form carnitine, an important amino acid that aids weight reduction, and helps to prevent heart disease.
Lysine supplements are widely available in health food stores, either on their own or incorporated in specific formulas.