Physiological Importance of riboflavin

Riboflavin, also called vitamin B-2, is one of several essential vitamins required as part of a balanced diet, as well as one of eight B-family vitamins.

Vitamin B2 is a water-soluble vitamin, so it dissolves in water. All vitamins are either water soluble or fat soluble.

Riboflavin is important for body growth. It helps in red blood cell production. It also aids in the release of energy from proteins.

Riboflavin is essential to the formation of two major coenzymes, flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD). Vitamin B-2 helps human body break down the three macronutrients -- protein, carbohydrate, and fat. Riboflavin, in the form of FAD, helps body break down fats and carbohydrates into fuel by contributing to the electron transport chain, a series of chemical reactions that give off usable energy for body cells.

Without an adequate amount of riboflavin, macronutrients like carbohydrates, fats, and proteins cannot be digested and maintain the body. With a healthy digestive system, the body can absorb most of the nutrients from the diet, so it is important to get most of the riboflavin from dietary sources.

Riboflavin also helps convert tryptophan to niacin, which activates vitamin B6. The conversion of vitamin B6 to the coenzyme pyridoxal 5'-phosphate requires FMN. Vitamin B-6 (pyridoxine) is important for normal brain development and for keeping the nervous system and immune system healthy.

Riboflavin (as FAD or FMN) is required for the metabolism of iron. It also plays an essential role in folate and related one-carbon metabolism, where FAD is required as a cofactor for methylenetetrahydrofolate reductase (MTHFR), a key folate-metabolizing enzyme.

Riboflavin also serves an antioxidant function due to its ability to activate antioxidant enzymes. Antioxidants protect body cells from damage caused by harmful chemicals called reactive oxygen species, or ROS.
Physiological Importance of riboflavin

Riboflavin in noodles

In the Malaysian and Filipino studies,31 the wheat flour used to make the instant noodles was fortified with two forms of iron (NaFeEDTA and ferrous fumarate) as well as folic acid, vitamin B-12, vitamin A, zinc, thiamin and riboflavin. Compounds and the fortification level were chosen according to WHO recommendations.

Instant noodles can be fortified either by fortifying the flour used to make the noodles or by fortifying the seasoning consumed along with the noodles. Micronutrients including vitamin A, B1, B2, niacin, folic acid, iron, and iodine can be added although the micronutrients and their overages will vary with each approach.

Riboflavin, chemically, is 7, 8-dimethyl-10-ribityl-isoalloxazine which consists of a flavin isoalloxazine ring bound to a sugar side chain, Ribitol. Riboflavin is also known as an essential vitamin B2, a water-soluble vitamin, is heat stable. Cooking does not lower levels of riboflavin, however exposure to light could destroy it.

Pure riboflavin was first isolated from milk in 1933 by Kuhn, Gyori and Wagner-Jauregg, working at the Kaiser Wilhelm Institute for Medical Research in Heidelberg, and it was chemically synthesized in 1934.

Riboflavin can be found in a wide variety of foods and natural sources, especially milk, organ meats—mostly in calf liver, egg, fish, nuts, certain fruits and legumes, wild rice, mushrooms, dark green leafy vegetables, yeast, beer, cheese and dietary products. Riboflavin is poorly stored by vertebrates because of its limited absorption in humans.
Riboflavin in noodles

Discovery of riboflavin

The British chemist Alexander W. Blyth in 1879 isolated from milk whey a water-soluble, yellow fluorescent compound he called lactochrome, appropriately named for its color and origin. ‘Lacto’ from the milk and ‘chrome’ meaning color because of the yellow pigment.

The search to identify these accessory food factors in milk, whole wheat, yeast, and liver began in the early 1900s.

McCollum and assistant Marguerite Davis produced three papers in 1915 which showed a diet containing 2% of wheat embryo or milk powder with polished rice, casein, salts, and butter fat provided enough of an ‘essential accessory’ to support growth of young rats.

The importance of lactochrome was not fully realized until later investigational studies by Elmer McCollum and Kennedy (1916), Emmett and Luros, and Smith and Hendrick that showed the preventive capabilities of water-soluble food extracts against beriberi, pellagra, and pellagra-like dermatitis.

Several years later, the physiological role of the yellow growth factor was shown by Warburg and Christian (1932) to be a component of a yeast “Zwischenferment,” which was designated the “old yellow enzyme.”

Joseph Goldberger in 1927 proposed there was an anti-pellagra factor in eggs, milk, etc., and it was the same substance as ‘water-soluble B’ identified by McCollum. Goldberger called the substance the pellagra-preventative or P-P dietary factor.

In 1935 Richard Kuhn at Heidelberg, and Paul Karrer at the University of Zurich eventually succeeded in synthesizing the vitamin, now termed riboflavin. They were awarded the Nobel Prize for this and other achievements in 1937 and 1938, respectively. Kuhn first proved that riboflavin is an essential growth factor, viz., vitamin B2.

Kuhn also developed a synthetic route to riboflavin which was licensed to the German company I. G. Farben.

Theorell in 1937 identified the isoalloxazine derivative from the old yellow enzyme as riboflavin-5′-phosphate, also called FMN (flavin mononucleotide). The structure of a second coenzymic form was established by Warburg and Christian (1938) as FAD (flavin adenine dinucleotide) and was shown to participate as the coenzyme of d-amino acid oxidase.
Discovery of riboflavin

Ariboflavinosis

Riboflavin is essential in the diet and the human body is unable to synthesize this vitamin. It is a water-soluble, photosensitive, crystalline pigment the present of which can be determined by fluorometric as well as micro-biological and absorptive-photometrical methods.

Riboflavin is not stored in the body, requiring people to replenish supply daily from the diet. Food sources of riboflavin include: beef liver, dairy products, eggs, meat, wheat germ and tuna fish.

Riboflavin deficiency causes ariboflavinosis, a common nutritional deficiency disease.

In man the syndrome is said to consist of cheilosis, perlèche -like erosions, seborrhea of the face, vascularization of corneo and keratitis.

The facial and labial lesions of ariboflavinosis contribute largely to the typical facies of classic pellagra and with glossitis constitute the picture of "pellagra sine pellagra."

Photophobia, burning and itching of the eyes, a sensation of eyestrain or rapid visual fatigue, poor distant vision and blurred vision in poor light or twilight are specific symptoms.

Red blood cell glutathione reductase activity can be measured for evidence of deficiency, but usually clinical findings are sufficient to consider deficiency.
Ariboflavinosis

Riboflavin: Water soluble vitamin

Riboflavin is a water-soluble member of the B-vitamin family. It was first documented in 1879 by Alexander W. Blyth as a yellow pigment found in milk. Riboflavin, chemically, is 7, 8-dimethyl-10-ribityl-isoalloxazine which consists of a flavin isoalloxazine ring bound to a sugar side chain, Ribitol.

Riboflavin is the precursor to the coenzymes, flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD). FMN and FAD serve as coenzymes for flavoproteins involved in a wide variety of oxidation–reduction reactions in intermediary metabolism.

A shortage of this vitamin may manifest itself as weakness, fatigue, cracks and sores at the corners of the mouth, eye disorders, inflammation of the mouth and tongue, and skin lesions. More advanced deficiency may result in cheilosis, angular stomatitis, dermatitis, corneal vascularisation, anemia and brain dysfunction.

Food sources of riboflavin: legumes, including chick peas, lentils, red and black gram, soya bean, beef, mutton, chicken, duck, fishes, egg yolk.

The estimated average requirement and RDA for riboflavin that cover men and women between the ages of 19 and 70 years old are 0.9–1.1 and 1.1–1.3 mg/d, respectively.
Riboflavin: Water soluble vitamin

Milk: Excellent source of vitamin B

Milk contains both water-soluble and fat-soluble vitamins. The nonfat portion of milk is especially plentiful in the B vitamin riboflavin, a greenish fluorescent-colored vitamin. It acts as a photosynthesizer and is readily destroyed upon exposure to sunlight.

Dairy milk contains more vitamin B than soy milk. It has 8 types of vitamin B, compared to soy milk which contains 7 types but lacking in vitamin B12.

Vitamin B12

Vitamin B12 is necessary for growth, maintenance of nerve tissues and normal blood formation, Milk provides 0.44 μg vitamin B12/100 g. Three glasses of milk would furnish all of the 2.4 μg vitamin B12 recommended for most adults.

Vitamin B12 content was measured in milk samples of 544 Dutch Holstein Friesian cows: content was 4.4 μg/L on average and varied between 1.0 and 12.9 μg/L. This variation between cows could to large extend be attributed to genetic factors.

Riboflavin or B2 vitamin is a yellow-green fluorescent compound and in addition to its role as a vitamin, it is responsible for the colour of milk serum.
Milk: Excellent source of vitamin B 

Pantothenic acid

Pantothenic acid
Pantothenic acid, a vitamin required for normal growth, nerve development and normal skin is a component of enzyme systems involved in metabolism (e.g., acetylation processes). It is believes and there is evidence, that Pantothenic acid is intimately related to riboflavin in human nutrition.
Deficiencies symptoms can be successfully treated with either compound. Deficiencies of this vitamin cause degeneration of nerve tissues with resulting muscular weakness, numbness and malaise.

Scaling skin and dermatitis, diarrhea with bloody stools, and ulceration of the intestine are also deficiency symptoms. The organs of animals (liver, heart, kidneys) and eggs, whole wheat products and peanuts are excellent sources of Pantothenic acid. The muscular tissue of animals, cheese, beans, cauliflower, broccoli, mushrooms and salmons are very good sources of this vitamin.
Pantothenic acid

B Vitamins – Thiamin and Riboflavin

B Vitamins – Thiamin and Riboflavin
Thiamin
The B vitamins are water soluble. Thiamin – vitamin B1 is involved in all bodily oxidations that lead to the formation of carbon dioxide. It is necessary for nerve function, appetite, and normal digestion. It is also required for growth, fertility, and lactation. The symptoms of vitamin deficiency are retardation of growth, palpitation and enlargement of the heart, hypertension, and beriberi. The various effects of a disturbance of the nerve centers such as forgetfulness or difficulty in thinking are other manifestations of vitamin B1 deficiency. The vitamin is often lacking in the diet because much of the naturally occurring amounts of it in food are destroyed during the processing of the food. The adult requirement of vitamin B1 is related to the food (calorie) intake. Fresh pork is an excellent source of vitamin B1 and the heart, liver, and kidneys of pork, beef and lamb are fair sources.

Riboflavin
Riboflavin – vitamin B2 is water soluble. This vitamin makes up a part of enzyme systems involved in the oxidation and reduction of different materials in the body. Deficiency of riboflavin generally results in growth retardation and may result in vision impairment, sealing of the skin, and lesions on mucous tissue. Neuritis is another deficiency effect. The minimum intake of riboflavin for an adult is about 2.0mg per day. The liver and kidney of pork, beef, and lamb are excellent sources of riboflavin, and the heart of these animals is a good source. Fair amounts of riboflavin are found in the muscular tissues of pork, beef, and lamb, while more is found in veal.
B Vitamins – Thiamin and Riboflavin