Ariboflavinosis
Encyclopedia
Ariboflavinosis is the medical condition caused by deficiency of riboflavin
Riboflavin
Riboflavin, also known as vitamin B2 or additive E101, is an easily absorbed micronutrient with a key role in maintaining health in humans and animals. It is the central component of the cofactors FAD and FMN, and is therefore required by all flavoproteins. As such, vitamin B2 is required for a...

 (vitamin B2). Ariboflavinosis is most often seen in association with protein-energy malnutrition
Protein-energy malnutrition
Protein-energy malnutrition refers to a form of malnutrition where there is inadequate protein intake.Types include:* Kwashiorkor...

, and also in cases of alcoholism
Alcoholism
Alcoholism is a broad term for problems with alcohol, and is generally used to mean compulsive and uncontrolled consumption of alcoholic beverages, usually to the detriment of the drinker's health, personal relationships, and social standing...

.

It was originally known as pellagra sin pellagra (pellagra without pellagra), as it exhibits certain similarities to the niacin
Niacin
"Niacin" redirects here. For the neo-fusion band, see Niacin .Niacin is an organic compound with the formula and, depending on the definition used, one of the forty to eighty essential human nutrients.Niacin is one of five vitamins associated with a pandemic deficiency disease: niacin deficiency...

 deficiency pellagra
Pellagra
Pellagra is a vitamin deficiency disease most commonly caused by a chronic lack of niacin in the diet. It can be caused by decreased intake of niacin or tryptophan, and possibly by excessive intake of leucine. It may also result from alterations in protein metabolism in disorders such as carcinoid...

.

The US Recommended Daily Allowance (RDA) for riboflavin ranges from 1.1 to 1.3 milligrams per day for healthy adults to as high as 1.6 mg/day for pregnant or nursing women.

Causes

The most common cause of riboflavin deficiency is an inadequate diet; thus, it occurs most frequently in populations consuming limited quantities of riboflavin-containing foods such as meat
Meat
Meat is animal flesh that is used as food. Most often, this means the skeletal muscle and associated fat and other tissues, but it may also describe other edible tissues such as organs and offal...

s, egg
Egg (food)
Eggs are laid by females of many different species, including birds, reptiles, amphibians, and fish, and have probably been eaten by mankind for millennia. Bird and reptile eggs consist of a protective eggshell, albumen , and vitellus , contained within various thin membranes...

s, milk
Milk
Milk is a white liquid produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals before they are able to digest other types of food. Early-lactation milk contains colostrum, which carries the mother's antibodies to the baby and can reduce the risk of many...

, cheese
Cheese
Cheese is a generic term for a diverse group of milk-based food products. Cheese is produced throughout the world in wide-ranging flavors, textures, and forms....

, yogurt, leafy green vegetables and whole grain
Whole grain
Whole grains are cereal grains that contain cereal germ, endosperm, and bran, in contrast to refined grains, which retain only the endosperm. Whole grains can generally be sprouted while refined grains generally will not sprout. Whole-meal products are made by grinding whole grains in order to make...

s. Riboflavin deficiency can also occur in those with impaired liver
Liver
The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...

 function, which prevents proper use of the vitamin. Borderline riboflavin deficiency as a consequence of certain anti-retroviral medications has also been known to cause acute lactic acidosis
Lactic acidosis
Lactic acidosis is a physiological condition characterized by low pH in body tissues and blood accompanied by the buildup of lactate especially D-lactate, and is considered a distinct form of metabolic acidosis. The condition typically occurs when cells receive too little oxygen , for example...

.

An animal model of riboflavin kinase
Riboflavin kinase
In enzymology, a riboflavin kinase is an enzyme that catalyzes the chemical reactionThus, the two substrates of this enzyme are ATP and riboflavin, whereas its two products are ADP and FMN....

 deficiency has been identified.

Presentation

The signs and symptoms of riboflavin deficiency typically include sore throat with redness and swelling of the mouth and throat mucosa, cheilosis and angular stomatitis
Stomatitis
Stomatitis is an inflammation of the mucous lining of any of the structures in the mouth, which may involve the cheeks, gums, tongue, lips, throat, and roof or floor of the mouth...

 (cracking of the lips and corners of the mouth), glossitis
Glossitis
Glossitis is inflammation of the tongue. It causes the tongue to swell and change color. Finger-like projections on the surface of the tongue may be lost, causing the tongue to appear smooth....

 (magenta tongue with atrophy), seborrheic dermatitis or pseudo-syphilis (moist, scaly skin particularly affecting the scrotum
Scrotum
In some male mammals the scrotum is a dual-chambered protuberance of skin and muscle containing the testicles and divided by a septum. It is an extension of the perineum, and is located between the penis and anus. In humans and some other mammals, the base of the scrotum becomes covered with curly...

 or labia majora
Labia majora
The labia majora are two prominent longitudinal cutaneous folds that extend downward and backward from the mons pubis to the perineum and form the lateral boundaries of the pudendal cleft, which contains the labia minora, interlabial sulci, clitoral hood, clitoral glans, frenulum clitoridis, the...

 and the nasolabial folds), and a decreased red blood cell count with normal cell size and hemoglobin
Hemoglobin
Hemoglobin is the iron-containing oxygen-transport metalloprotein in the red blood cells of all vertebrates, with the exception of the fish family Channichthyidae, as well as the tissues of some invertebrates...

 content (normochromic normocytic anemia
Anemia
Anemia is a decrease in number of red blood cells or less than the normal quantity of hemoglobin in the blood. However, it can include decreased oxygen-binding ability of each hemoglobin molecule due to deformity or lack in numerical development as in some other types of hemoglobin...

).

Riboflavin deficiency is usually found together with other nutrient deficiencies, particularly of the other water-soluble vitamin
Vitamin
A vitamin is an organic compound required as a nutrient in tiny amounts by an organism. In other words, an organic chemical compound is called a vitamin when it cannot be synthesized in sufficient quantities by an organism, and must be obtained from the diet. Thus, the term is conditional both on...

s. Phototherapy to treat jaundice
Jaundice
Jaundice is a yellowish pigmentation of the skin, the conjunctival membranes over the sclerae , and other mucous membranes caused by hyperbilirubinemia . This hyperbilirubinemia subsequently causes increased levels of bilirubin in the extracellular fluid...

 in infants can cause increased degradation of riboflavin, leading to deficiency if not monitored closely. Persons with chronic alcoholism can have impaired absorption of riboflavin and other vitamins such as thiamine
Thiamine
Thiamine or thiamin or vitamin B1 , named as the "thio-vitamine" is a water-soluble vitamin of the B complex. First named aneurin for the detrimental neurological effects if not present in the diet, it was eventually assigned the generic descriptor name vitamin B1. Its phosphate derivatives are...

 (see Wernicke's encephalopathy
Wernicke's encephalopathy
Wernicke encephalopathy is a syndrome characterised by ataxia, ophthalmoplegia, confusion, and impairment of short-term memory.It is caused by lesions in the medial thalamic nuclei, mammillary bodies, periaqueductal and periventricular brainstem nuclei, and superior cerebellar vermis, often...

).

Studies of the Turkoman
Iraqi Turkmen
The Iraqi Turkmen are an ethnic group who mainly reside in northern Iraq. Estimates of their numbers vary dramatically, in accordance with Iraq's assimilation policies no realistic and independent census results have been revealed regarding the Iraqi Turkmen population...

 people of Iran
Iran
Iran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia...

, who have a significantly increased incidence of esophageal cancer
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...

, have shown some relationship between chronic riboflavin deficiency and the onset of esophageal malignancies.

One study of pregnant women has found that riboflavin-deficient women were 4.7 times more likely to develop preeclampsia, though the mechanism for this is not known.

USMLE step 1 book indicates that corneal vascularization is also a presentation for B2 deficiency.

Treatment

Treatment involves a diet which includes an adequate amount of riboflavin. In cases related to weakened liver function, intravenous supplementation may be required.

External links

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