Lysine is an essential amino acid needed
for growth and to help maintain nitrogen balance in the body. (Essential amino acids cannot be
made in the body and must be supplied by the diet or supplements.)
Lysine has been used in
connection with the following conditions (refer to the individual
health concern for complete information):
Who is likely to be deficient?
Most people, including vegans (vegetarians
who also avoid dairy and eggs), consume adequate amounts of lysine. However,
vegans whose diets contain large amounts of
grains and only minimal amounts of beans
could become deficient in lysine. Athletes
involved in frequent vigorous exercise have increased need for essential amino acids, although most diets meet these increased
needs. The essential amino acid requirements of
burn patients may exceed the amount of lysine in the diet.
How much is usually taken?
Most people do not require lysine supplementation. Doctors often suggest that people with
recurrent herpes simplex infections take
1,000–3,000 mg of lysine per day.
Are there any side effects or interactions?
In animals, high amounts of lysine have been linked to increased risk of gallstones1 and elevated cholesterol.2 At supplemental
amounts, no consistent problems have been reported in humans, though abdominal cramps and
transient diarrhea have occasionally been
reported at very high (15–40 grams per day) intakes.3
Lysine supplementation increases the absorption of calcium and may reduce its excretion.4 As a
result, some researchers believe that lysine may eventually be shown to have a role in the
prevention and treatment of
osteoporosis.5
Lysine works with other essential amino
acids to maintain growth, lean body mass, and the body’s store of nitrogen.
At the time of writing, there were no well-known drug interactions
with lysine.
References:1. Kritchevsky D, Weber MM, Klurfeld DM. Gallstone formation in hamsters:
influence of specific amino acids. Nutr Rep Int 1984;29:117.
2. Leszczynski DE, Kummerow FA. Excess dietary lysine induces
hypercholesterolemia in chickens. Experientia 1982;38:266–7.
3. Flodin NW. The metabolic roles, pharmacology, and toxicology of
lysine. J Am Coll Nutr 1997;16:7–21 [review].
4. Civitelli R, Villareal DT, Agnusdei D, et al. Dietary L-lysine and
calcium metabolism in humans. Nutrition 1992;8:400–5.
5. Flodin NW. The metabolic roles, pharmacology, and toxicology of
lysine. J Am Coll Nutr 1997;16:7–21 [review].