Vitamin B2 or Riboflavin was encountered late in the 19th century when laboratory workers observed a yellow green fluorescent pigment that formed crystals. The complex, originally named vitamin B2.
Absorption, metabolism and, excretion – absorption of vitamin B2 occurs in the small intestine. Although the greatest concentration of vitamin B2 found in the liver, kidneys, and heart, only small amounts are stored in the liver and kidneys, so daily needs must be met in the diet. The kidney excretes excess vitamin B2 so that even an intake of 1.7 milligrams of riboflavin imparts a bright yellow color to the urine. Excretion is enhanced by diabetes mellitus, stress, and trauma.
Functions of Vitamin B2
Energy production – riboflavin is an essential part of the coenzymes, flavin mononucleotide9FMN) and flavin-adenine dinucleotide (FAD). FAD and FMN play central roles in numerous metabolic pathways of carbohydrate, fatty acid, and protein metabolism.
Antioxidant action – vitamin B2 is a cofactor of glutathione reductase. This enzyme helps, recycle oxidized glutathione, maintaining tissue antioxidant defenses.
Foods with Vitamin B2
Yogurt, cheese, egg whites, liver, beef, chicken, fish, legumes, peanuts, enriched grains and fortified cereals. Body size, growth, activity excess and fat metabolism affect daily requirements. As protein intake increases need of vitamin B2 decreases.
Increased risk of Vitamin B2 Deficiency
Childhood and adolescent growths, as well as pregnancy and lactation, increases demand for riboflavin.
Malabsorption of vitamin B2 occurs in tropical sprue, celiac disease, resection of the small intestine, gastrointestinal and biliary obstructions, chronic diarrhoea, infectious enteritis, and irritable bowel syndrome.
Thyroid hormones, oral contraceptives, barbiturates, and certain antibiotics can impair vitamin B2 status.
Heavy alcohol consumption reduces absorption of vitamin b2
The increased metabolism and protein breakdown that occur during chronic illness, fever, cancer, and injury sharply increases metabolism of riboflavin.
Signs and symptoms of vitamin B2 deficiency
- Reddened, scaly, greasy, painful and itchy patches on the skin (especially around the nose, mouth, ears, the labia majora in females and the scortom in men)
- Painful fissures and cracks from the angles of the mouth (angular stomatitis) and on the lips. The tongue is smooth, purplish, and painful. Swollen, sore throat
- Redness, burning, and excessive tearing of the eyes, light sensitivity, Chronic deficiency can increase risk of developing cataract.
- Lethargy
- Depression
- Personality changes
- Anemia with decreased production of red blood cells
Stability
Vitamin B2 is relatively stable to heat but is sensitive to ultraviolet light. Thus, cardboard milk, cartons or opaque plastic bottles would be more protective of the vitamin then clear glass bottles.
Interfering factors
Iron, zinc, copper, and manganese have been shown to inhibit riboflavin absorption. Drinking alcohol impairs digestion and absorption of vitamin B2.
Use of Vitamin B2 in prevention and therapy
Detoxification – vitamin B2 helps the liver detoxify chemicals, pesticides, and other environmental toxins.
Antioxidant functions – vitamin B2 functions as an antioxidant throughout the body and may be especially important in the lenses of the eye. Ample intake of riboflavin can reduce the risk of developing cataract.
Fatigue and depression – in people with increased vitamin B2 requirements, dietary inadequacy may produce a suclinical deficiency that causes fatigue, depression, and personality changes. This may respond to vitamin B2 supplementation.
Skin and mucus membrane – ample vitamin B2 intake maintains the health of the skin and mucus membranes. It may be beneficial in stomatitis, cheilosis, and skin eruptions and rashes.
