Have you heard of L-carnitine?
What is L-Carnitine: derived from an amino acid, is a collective term for several compounds, including L-carnitine, acetyl-L-carnitine, and propionyl-L-carnitine. Carnitine is naturally found in many foods, especially animal products, and is also available as a dietary supplement. Carnitine is also endogenously synthesized in the liver, kidneys, and brain from the amino acids lysine and methionine. While many people have heard of L-carnitine and it is commonly understood to aid in weight loss, its scientifically proven benefits include fat loss, muscle mass increase, and fatigue reduction. Therefore, understanding what L-carnitine is and its benefits for the body is important for proper intake. Carnitine plays a key role in energy production. It is an essential coenzyme for generating energy in the form of adenosine triphosphate (ATP).
About L-Carnitine：L-carnitine is a substance that the body can produce itself in the liver and kidneys from two amino acids, lysine and methionine. It helps the body use fat for energy. Therefore, L-carnitine plays an important role in the breakdown of fatty acids in the body. Carnitine also helps transport some toxic compounds from the mitochondria. Additionally, the body obtains L-carnitine from foods such as red meat, nuts, and avocados. The body requires approximately 15 mg of carnitine per day, both from dietary intake and endogenous synthesis. Most of the carnitine in the American diet comes from animal products. A typical omnivore, weighing 165 pounds, can obtain approximately 24–145 mg of carnitine per day. Vegetarians, on the other hand, can obtain approximately 1.2 mg of carnitine. Endogenous carnitine synthesis appears unaffected by dietary carnitine intake or carnitine excretion and is sufficient to meet the carnitine requirements of healthy individuals. For example, a 165-pound (74.8 kg) strict vegetarian synthesizes approximately 14.4 mg/day of carnitine.Carnitine status is not routinely assessed in clinical practice, but it can be determined by measuring circulating carnitine. Plasma free carnitine concentrations below 20 mcmol/L or total carnitine concentrations below 30 mcmol/L are abnormally low. Additionally, because most carnitine is normally in the free, unesterified form, the ratio of acyl-L-carnitine esters to free L-carnitine can also be used to assess carnitine status. A ratio of 0.4 or higher in plasma or serum suggests abnormal carnitine metabolism and carnitine deficiency.
Effect of L-Carnitine：One study evaluated the effects of L-carnitine in obese women and compared the effects between four groups. Group 1 received a placebo, group 2 received L-carnitine, group 3 received exercise and a placebo, and group 4 received exercise and L-carnitine. Over an 8-week follow-up period, the group that combined aerobic exercise with daily intake of 2 grams of L-carnitine demonstrated a statistically significant reduction in internal inflammation (hs-CRP). Another study in elderly subjects also administered 2 grams daily, resulting in increased muscle mass, decreased fat mass, and decreased physical fatigue.carnitine is highly effective with very few side effects. When combined with exercise, it is recommended to exercise for at least 40–50 minutes per day. Athletes and those taking additional L-carnitine for the purposes of reducing body fat or improving muscle function should discontinue use at least one week per month to allow muscles to rest and should not use it continuously for extended periods of time.
carnitine deficiency
Infertility: L-Carnitine has been implicated in sperm maturation, motility, and spermatogenesis. It has also been shown to reduce oxidative stress and improve oocyte growth and maturation. Therefore, research is ongoing to determine whether carnitine supplementation can improve sperm count, concentration, motility, and pregnancy rates.
Osteoarthritis: L-Carnitine has been shown to reduce levels of C-reactive protein, a biomarker of systemic inflammation, and malondialdehyde, a lipid peroxidation product that induces pain and disability in patients with osteoarthritis. Furthermore, levels of acylcarnitines (conjugated carnitine esters) are lower in patients with osteoarthritis compared with age- and sex-matched healthy controls.