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The absence of the pale arched area at the proximal portion of the nail plate.

An eruption of velvet warty benign growths and hyperpigmentation occurring in the skin of the axillae, neck, anogenital area, and groin. It may be associated with internal malignancy, endocrine disorders or obesity in adults. A benign type occurs in children.

An ADI is "the amount of a food additive, corrected for body weight, that can be ingested daily over a lifetime without appreciable health risk". The ADI is determined by bodies such as HPFB, JECFA, or FDA and is generally 1% of the highest dose at which studies have demonstrated no harmful effects.

A range of intakes for a particular energy source that is associated with a reduced risk of chronic disease while providing adequate intakes of essential nutrients. The AMDR of a macronutrient is expressed as a % of total energy intake because its requirement is not independent of other energy fuel sources or of the total energy requirement of the individual.

Acetaldehyde is an intermediate in the metabolism of alcohol.

Acetic acid is a biochemical product of metabolism. It is also called ethanoic acid and is a carboxylic acid.

Acetylcholine is a neurotransmitter that stimulates nerve transmission in the brain. It is derivative of choline and acetic acid.

Acid reflux is the backward flow of stomach acid and juices into the esophagus or throat, which may cause heartburn.

A major contractile protein in muscle found in thin filaments.

includes 1,25(OH)2D3 (calcitriol) and 1-α derivatives (alfacalcidol).

Acute decompensated heart failure is a clinical diagnosis which occurs when an individual experiences a rapid onset of heart failure symptoms (shortness of breath, fatigue, edema) that requires urgent medical attention, often resulting in visits to the emergency department and hospitalization.

Acute gastroenteritis is a diarrheal disease of rapid onset, with or without accompanying symptoms and signs, such as nausea, vomiting, fever, or abdominal pain.

Acute phase proteins are a class of proteins that are synthesized in the liver in response to inflammation. This response is called the acute phase reaction.

Ad libitum is a latin term that means as a person wishes.

Added salt refers to salt that is added during cooking or after preparation (at the table).

Adequate Intake (AI) is the recommended average daily nutrient intake level based on observed or experimentally determined approximations or estimates of nutrient intake by a group (or groups) of apparently healthy people that are assumed to be adequate. It is used when the RDA cannot be determined.

Adiponectin is a protein hormone secreted by adipose tissue. It is involved in glucose regulation and fatty acid catabolism and plays a role in the suppression of metabolic derangements that may result in type 2 diabetes, obesity, atherosclerosis and non-alcoholic fatty liver (NAFLD).

Adiposity rebound is the increase in BMI that occurs after it reaches its lowest point, which is a normal pattern of growth that occurs in all children.

The adjusted distribution represents the "distribution of usual nutrient intake" for the group and removes the day-to-day variability of intake within an individual.

An aeroallergen is an allergen that is airborne. Aeroallergens usually cause symptoms because they are able to enter the body via the respiratory tract.

Aerobic exercise consists of rhythmic, repeated and continuous movements of the same large muscle groups for at least 10 minutes at a time. Examples include walking, biking, jogging, swimming, water aerobics and many sports.

Agility is the ability to move and change position of the body and direction quickly and effectively while under control.

Airway surface liquid is the 10-30μM layer of fluid on the epithelial cells of the pulmonary tissue located at the interface between inspired air and the respiratory lining.

All rac (racemic) alpha-tocopherol is synthetic vitamin E.

Allele is one of the variant forms of a gene at a particular location on a chromosome. Different alleles produce variation in inherited characteristics such as hair color or blood type. In an individual, one form of the allele (the dominant one) may be expressed more than another form (the recessive one).

An allergen is a special type of antigen that causes an IgE antibody response.

An allergen-specific IgE is an IgE antibody formed in response to a specifc allergen. These are the antibodies that are detected in allergy tests such as RAST and skin tests.

Allergic asthma refers is asthma caused by immunological mechanisms.

Allergic disease is caused by exposure to specific antigens (allergens) in people who are sensitized to the antigens.

Allergic eosinophilic gastroenteritis is a food-related gastrointestinal hypersensitivity disease involving IgE and/or non-IgE mechanisms. It can occur at any age, including in young infants. Weight loss or failure to thrive is typical for this disorder.

Allergic rhinitis is an inflammation of the nasal mucous membrane induced by IgE antibody to specific allergens.

Allergic sensitization is the presence of IgE antibodies against environmental and/or food antigens.

An allergy is an inappropriate or exaggerated reaction of the immune system to substances that, in the majority of people, cause no symptoms. Symptoms of allergic disease may be caused by exposure of the skin to a chemical, of the respiratory system to particles of dust or pollen (or other substances), or of the stomach and intestines to a particular food. In its broadest sense, it is applied to all types of immunologically-mediated hypersensitivity reactions. Previously, the term was restricted to IgE-mediated hypersensitivity.

Alopecia is a complete or partial loss or absence of hair.

Alopecia areata is a condition of undetermined etiology characterized by non-scarring and circumscribed areas of baldness on the scalp, eyebrows and beard area which are usually asymmetric.

Alopecia totalis is a complete loss of scalp hair.

Alopecia universalis is the total loss of all body hair.

Alpha-tocopherol is the biologically active form of vitamin E. It has three asymmetric carbon atoms in the side chain, at positions 2, 8 and 12, each of which can be designated as "R" or "S". This formation leads to eight possible stereoisomers: RRR, RSR, RRS, RSS, SRR, SSR, SRS, and SSS. The naturally-occurring form of alpha-tocopherol is RRR-alpha-tocopherol. For the purposes of establishing requirements and recommended intakes, vitamin E is defined as the two R-stereoisomers of alpha-tocopherol (i.e. RRR, RSR, RRS and RSS).

Alpha-tocopherol equivalents (TE) are used in most nutrient databases to show the vitamin E content of foods. This unit incorrectly attributes vitamin E activity to tocopherols and tocotrienols other than alpha-tocopherol. The new RDA is for alpha-tocopherol only.

Amyotrophic lateral sclerosis, also known as Lou Gehrig''s disease, occurs in the motor tracts of the lateral columns and anterior horns of the spinal cord causing progressive muscular atrophy, increased reflexes, fibrillary twitching, and spastic irritability of muscles.

Anaphylactoid is a reaction with symptoms often indistinguishable from anaphylaxis in people in whom no evidence of IgE-mediated allergy can be demonstrated.

Anaphylaxis is a serious allergic reaction that is rapid in onset and may cause death. Signs and symptoms can occur within minutes of exposure to an allergen. In rarer cases, the time frame can vary up to several hours after exposure. The ways that these symptoms occur may vary from person to person and even from episode to episode in the same person. An anaphylactic reaction can involve any of the following symptoms: (skin) hives, swelling, itching, warmth, redness, rash, (respiratory)coughing, wheezing, shortness of breath, chest pain/tightness, throat tightness, hoarse voice, nasal congestion or hay fever-like symptoms (runny, itchy nose and watery eyes, sneezing), trouble swallowing, (gastrointestinal) nausea, pain/cramps, vomiting, diarrhea, (cardiovascular) pale/blue colour, weak pulse, passing out, dizzy/lightheaded, shock, (other) anxiety, feeling of “impending doom”, headache, uterine cramps in females. These symptoms may appear alone or in any combination regardless of the triggering allergen.

An anchor statement is intended to provide context to individuals by helping them understand the relationship between the caloric content of a menu item and the total amount of energy individuals should consume in one day.

Androgenic alopecia is a gradual decrease of scalp hair due to a familial increased susceptibility of hair follicles to androgen secretion following puberty. This condition is referred to as male pattern baldness and female pattern baldness.

Angioedema is swelling similar to urticaria (hives), but the swelling occurs beneath the skin instead of on the surface. Angioedema is characterized by deep swelling around the eyes and lips and sometimes of the hands and feet.

An antibody is a protein, also called an immunoglobulin (Ig), that is manufactured by lymphocytes to neutralize an antigen. Humans make five types of antibodies - IgA, IgD, IgE, IgG,and IgM.

An antigen is a substance that can trigger an immune response, resulting in production of an antibody as part of the body''s defense against infection and disease. Many antigens are foreign proteins (those not found naturally in the body). Bacteria, viruses and other microorganisms commonly contain many antigens, as do pollens, dust mites, molds, foods, and other substances.

An antigen presenting cell is a white blood cell that engulfs and degrades foreign proteins and displays the individual molecules on surface receptors for recognition by T helper cells.

Antigen processing is the display of antigens on the surface of a macrophage that has engulfed and partially degraded them, a preconditioning for recognition and a protective response by T cells.

Antigenicity is the ability of an antigen to trigger an immune response.

Antigen-specifc IgE is an IgE antibody that is formed against a specific antigen.

An antioxidant is a natural compound found in foods that significantly decreases the adverse effects of reactive species, such as reactive oxygen and nitrogen, on normal physiological function in humans.

Apolipoprotein E epsilon4 is the only fully established susceptibility allele for Alzheimer''''s disease. It is an allele of apolipoprotein E, a mediator of plasma lipoprotein metabolism and is a known cardiovascular risk factor for elevated cholesterol, atherosclerosis, myocardial infarction, and a suspected risk factor for dementia.

Apoptosis is programmed cell death.

Asthenospermia is the loss or reduction of motility of the spermatozoa which is frequently associated with infertility.

Asthenozoospermia is the loss or reduction of mobility of the spermatozoa which is frequently associated with infertility.

Asthma is a condition marked by recurrent episodes of breathing difficulty with wheezing due to spasmodic contraction of the bronchi.

Atopic dermatitis, also called atopic eczema, chronic inflammatory skin disorder seen in individuals with a hereditary predisposition to a lowered cutaneous threshold to pruritus, often accompanied by allergic rhinitis, hay fever, and asthma, and principally characterized by extreme itching, leading to scratching and rubbing that in turn results in the typical lesions of eczema.

Atopic disease is a genetic predisposition toward the development of immediate (Type I) hypersensitivity reactions against common environmental allergens (atopic allergy). The most common clinical manifestations are allergic rhinitis, bronchial asthma, atopic dermatitis, and food allergy occurring less frequently.

Atopy is a personal or familial tendency to produce IgE antibodies in response allergens, and to develop typical symptoms such as asthma, rhinoconjunctivitis or eczema/dermatitis.

Autonomic symptoms are symptoms manifested by activation of the autonomic nervous system: trembling, palpitations, sweating, anxiety, hunger, nausea and tingling.

Average Daily Intake refers to the average intake of a particular nutrient over time.

Average Requirement is the nutrient intake value that is estimated to meet the requirement defined by a specified indicator of adequacy in 50% of the individuals in a life stage and gender group. At this level of intake, the remaining 50% of the specified group would not meet their nutrient needs.