Vitamins, Minerals and Dietary Supplements

What is lysine? Why do we need it?

Lysine is an essential amino acid. It is different from other amino acids in that it contains two amino groups, which can react with other substances to create chemical compounds. Although the body does manufacture some lysine, it doesn't produce an adequate supply, so it must be obtained through a proper diet.

Lysine provides the structural components for the synthesis of carnitine, which promotes the synthesis of fatty acids. It plays an important role in the development of a person's growth by regulating the absorption of calcium, and also plays a role in the formation of collagen.

Lysine supplements are used to treat herpes infections; studies have found that lysine can increase the speed of recovery and prevent future infections from occurring. Some studies have shown that lysine may be helpful in treating cardiovascular disease, osteoporosis, asthma, migraines, and nasal polyps.

How much lysine should I take?

According to the National Research Council, the following doses of lysine are recommended:

Children 0-4 months: 103 milligrams per kilogram of body weight per day

Children 5-24 months: 69 milligrams per kilogram of body weight per day

Children 3-12 years: 44 milligrams per kilogram of body weight per day

Teenagers and adults: 12 milligrams per kilogram of body weight per day

Independent studies suggest that adults may need as much as 30 milligrams of lysine per kilogram of body weight per day.

What are some good sources of lysine?

Good sources of lysine include meat (particularly red meat), cheese, poultry, sardines, nuts, eggs and soybeans. Other sources include torula yeast, dried and salted cod, pork loin, tofu, parsley, soybean flour, and dried spirulina seaweed.

What can happen if I don't get enough lysine?

In children, a lysine deficiency can lead to stunted growth; in adults, it can lead to kidney stones. A general lack of lysine in the diet can also lead to fatigue, nausea, dizziness, loss of appetite, decreased immunity, anemia, pneumonia, acidosis, and bloodshot eyes.

What can happen if I take too much?

Although lysine is considered non-toxic, it may be linked with an increase in blood cholesterol and triglyceride levels. If you have cardiovascular disease or problems with blood cholesterol and/or triglycerides, make sure to talk with your health care provider before taking lysine supplements.

---

References

• Bruzzese N, Sica G, Iacopino F, et al. Growth inhibition of fibroblasts from nasal polyps and normal skin by lysine acetylsalicylate. Allergy 1998;53:431—434.
• De los Santos AR, Marti MI, Espinosa D, Di Girolamo G, Vinacur JC, Casadei A. Lysine clonixinate vs. paracetamol/codeine in postepisiotomy pain. Acta Physiol Pharmacol Ther Latinoam 1998;48(1):52—58.
• Ensminger AH, Ensminger ME, Konlande JE, Robson JRK. Foods & Nutrition Encyclopedia, 2nd ed. Baton Rouge, FL: CRC Press, Inc; 1994, pp. 1,2:60—64, 1,748.
• Flodin NW. The metabolic roles, pharmacology, and toxicology of lysine. J Am Coll Nutr 1997;16:7—21.
• Hugues FC, Lacoste JP, Danchot J, Joire JE. Repeated doses of combined oral lysine acetylsalicylate and metoclopramide in the acute treatment of migraine. Headache 1997;37:452—454.