Valine

 

Valine Introduction

Valine is classified as an essential amino acid and is a member of the branched-chain amino acid family. Molecularly, valine possesses similarities found in both isoleucine and leucine in regards to its overall structure and function. Valine is formed via the hydrolysis of specific proteins. Hydrolysis refers to a chemical reaction that takes place when water is used to form a given compound.

Valine is abundant in virtually all muscular tissue in the body. It is critical for processes relating to muscle metabolism, tissue repair, and nitrogen balance. [1] A precursor in the penicillin biosynthetic pathway, valine may also be used as an alternate source of energy by muscular tissues. Valine is rare among amino acids, in that it produces a stimulating effect within the body. Despite this characteristic, valine remains an essential component of nearly all proteins consumed in the human diet.

Valine Food Sources

The best dietary sources of valine include red meat, dairy products, eggs, milk, and cheese. It is also found in abundance in soy protein products, mushrooms, and peanuts. Higher protein sources often contain ample amounts of branched-chain amino acids (BCAAs), which include valine. Serving sizes below are based upon 100 grams of a given food source and are expressed in milligrams, representing the amount of valine contained.

Baked Products
mg/100g Food Name
2345 Leavening agents, yeast, baker’s, active dry

Vegetables and Vegetable Products
mg/100g Food Name
3512 Seaweed, spirulina, dried

Nut and Seed Products
mg/100g Food Name
2800 Seeds, sesame flour, low-fat
2775 Seeds, sunflower seed flour
2650 Seeds, pumpkin and squash seed kernels, roasted, without salt [pepitas]
2557 Seeds, cottonseed flour, low fat (glandless)
2520 Seeds, cottonseed meal, partially defatted (glandless)
2258 Seeds, safflower seed meal, partially defatted
2252 Seeds, sesame flour, partially defatted

Legumes and Legume Products
mg/100g Food Name
4099 Soy protein isolate
3064 Soy protein concentrate
2418 Tofu, dried-frozen (koyadofu)
2418 Tofu, dried-frozen (koyadofu), prepared with calcium sulfate
2346 Soy flour, defatted
2322 Soy flour, low-fat
2243 Soy meal, defatted, raw
2189 Peanut flour, defatted
2115 Meat extender

Finfish and Shellfish Products
mg/100g Food Name
3236 Fish, cod, Atlantic, dried and salted

Dairy and Egg Products
mg/100g Food Name
5163 Egg, white, dried
2886 Egg, whole, dried
2853 Cheese, parmesan, shredded
2524 Cheese, parmesan, grated
2454 Cheese, parmesan, hard
2420 Milk, dry, nonfat, regular, with added vitamin A
2376 Milk, dry, nonfat, calcium reduced
2349 Milk, dry, nonfat, instant, without added vitamin A
2296 Milk, buttermilk, dried
2243 Cheese, gruyere
2183 Cheese, romano
2139 Cheese, swiss
2100 Cheese, goat, hard type

Snacks
mg/100g Food Name
2421 Snacks, pork skins, plain
2334 Snacks, pork skins, barbecue-flavor

[2]

Valine Uses

The supplementation of valine for specific health conditions remains partial. Individuals supplementing valine often use it in combination with the other two branched-chain amino acids (isoleucine and leucine). Because of its inclusion in BCAAs, valine has seen extensive use in the sport of bodybuilding and other competitive sports. L-valine supplementation is theorized as being beneficial for enhancing the performance of physical weight and aerobic training. [3, 4] Valine may assist in promoting the growth of muscle by energizing these athletes during training, and enhancing tissue repair during the post workout period.

Persons suffering from chemical dependencies may also benefit from the additional supplementation of valine. Severe amino acid deficiencies have been extensively witnessed in both alcoholics and drug addicts. Supplemental dosages of L-Valine are often used to correct these deficiencies, and may also be used to correct and reverse hepatic encephalopathy, or other degenerative neurological conditions. Hepatic encephalopathy, simply, refers to alcohol induced/related brain damage.

Other topics of the continued research into valine supplementation include liver disease and the muscular degeneration in severe trauma patients, especially post-surgery and severe burn patients. Conditions such as ammonia toxicity and diabetes in older adults, also continues to be thoroughly studied in assorted clinical applications.

Valine Dosages

The established Recommended Daily Allowance (RDA) for valine:

Requirement - mg. per kg. of body weight
Infant Child Adults
Histidine 33 not known not known
Isoleucine 80 28 12
Leucine 128 42 16
Lysine 97 44 12
S-containing amino acids 45 22 10
Aromatic amino acids 132 22 16
Threonine 63 28 8
Tryptophan 19 4 3
Valine 89 25 14

[5]

The recommended dosage per day of valine, and other branched-chain amino acids, is 25 - 65 milligrams per pound of bodyweight. It is recommended that supplemental valine be used in union with both isoleucine and leucine. In addition, the U.S. National Academy of Sciences recommends that healthy people achieve .36 grams of highly bioavailable protein for each pound of bodyweight - equaling 0.8 grams of protein, per kilogram of bodyweight.

Valine Toxicities and Deficiencies

Valine Deficiencies

Due to the profusion and variety of protein in Western diets, a valine deficiency is unlikely to occur. Symptoms of a deficiency may manifest themselves in a manner which would critical impair development and neurological functioning. Inadequate levels may negatively influence body growth and repair, inhibit neuropathic functioning, and anaemia. Anaemia is a variant of anemia, and is defined as a condition in which the blood is deficient in hemoglobin (red blood cells).

Deficiencies may be fatal in individuals suffering from the recessive genetic disorder, known as maple syrup disease (MSUD). Persons suffering from this condition are unable to metabolize valine, isoleucine, or leucine - the branched chain amino acids. MSUD is characterized by the inhibition, or complete lack of, the enzyme responsible for breaking down these three specific amino acids. Because the branched-chain amino acids are not completely broken down, they accumulate in the sweat, blood, and urine.

Valine Toxicities

Acute toxicity of valine often results in a crawling sensation on the skin. Unlike minimal toxicities, overdoses of valine are often accompanied by delusion, absorption into fantasy, and in the severest of cases, a linear, falling, or rocking hallucination known as vertigo. Toxicities of this nutrient are extremely rare.

References

1. Balch, Phyllis A., James F. “Amino Acids.” Prescription for Nutritional Healing. Ed. Amy C. Tecklenberg. New York, NY: Penguin Putnam Inc., 3rd Ed. 2000. 42-53.

2. Nutrition Data. “999 Foods; Highest in Valine.” (2004)

http://www.pdrhealth.com/drug_info/nmdrugprofiles/herbaldrugs/101840.shtml

3. Kelly GS. Sports Nutrition: A review of selected nutritional supplements for bodybuilders and strength athletes. Med Rev 1997;2: 184-201.

4. Blomstrand E, Ek S, Newsholme EA. Influence of ingesting a solution of branched-chain amino acids on plasma and muscle concentrations of amino acids during prolonged submaximal exercise. Nutrition 1996;12:485-90.

5. Zest for life information page. “RDA of amino acids.” (1999-2003) http://www.pdrhealth.com/drug_info/nmdrugprofiles/herbaldrugs/101840.shtml (14 Sept. 2004).