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L-lysine
Description
L-lysine is an essential amino acid that occurs naturally
as part of food proteins and cannot be manufactured by the
body. It is usually the limiting factor in the biological
availability of vegetable proteins and this means that vegetarians
(and especially vegans) have to plan their diets carefully
in order not to suffer from a deficiency of L-lysine.
Functions
L-lysine is an important structural component
of many proteins. It is also directly involved in the production
of L-carnitine, which is required for the transport, and utilisation
of fats.
Lysine is needed to make the non-essential
amino acid, carnitine, involved in fat transportation.
Two other roles in which L-lysine is involved
are retention of Calcium within the body and maintenance of
the Immune System (1).
Supplemental Uses
Cold Sores
One of the main uses of L-lysine is as a weapon against the
Herpes simplex virus, which causes cold sores.
L-lysine is an antagonist of L-arginine, and L-arginine is
known to feed the Herpes simplex virus. Oral doses of between
300 and 1200mg of L-lysine are thought to be effective (1).
Vegans
L-lysine supplements may be necessary for vegans or vegetarians,
especially if they have neither dairy products nor legumes
included in their diet. Fruit and vegetables contain very
little lysine (2).
Osteoporosis
The amino acid may also be a good adjunct nutrient in preventing
against Osteoporosis (3), because when L-lysine is deficient,
more Calcium
is lost in the urine.
Safety
Toxicity of L-lysine has not been reported
with levels as high as 8g per day.
Interactions and Contra-Indications
There are no known drug interactions or
other contra-indications for L-lysine.
N.B. L-lysine is unstable and has to be
presented as L-lysine hydroChloride (HCl) in supplements.
References
1. Flodin NW. The metabolic roles,
pharacology, and toxicology of lysine. J Am Coll Nutr, 16;1:7-21
1997.
2. "The Healing Nutrients Within", E R Braverman
& C C Pfeiffer, Keats, 1987.
3. Fürst P. Dietary L-lysine supplementation: a promising
nutritional tool in the prophylaxis and treatment of Osteoporosis.
Nutrition, 9;1:71-72 1993. | 
