Riboflavin

Riboflavin is a type of B vitamin naturally produced by the body. It is commonly known as vitamin B2. Working with other B vitamins, it is important for cell growth and repair, normal reproduction, tissue health, and metabolism. Like iron, riboflavin is vital for producing red blood cells and for the transportation of oxygen throughout the body. It bolsters the immune system and helps maintain healthy skin and hair. Along with other B vitamins, riboflavin helps to maintain healthy vision, helps protect the nervous system, and is necessary for a healthy liver.

A water-soluble nutrient, riboflavin is disposed of through the urine and must therefore be replenished in the body every day. Natural sources of riboflavin include milk, meat, eggs, legumes, green vegetables, mushrooms, enriched flour, and almonds. While a vitamin B2 deficiency is rare, it can lead to multiple significant complications. Treatment involves a diet with sufficient riboflavin-containing foods and vitamin supplements containing the recommended daily value for vitamin B2.

Background

Riboflavin is pronounced "RIE bow flay vin" and was formerly known as vitamin G. Alternative names for riboflavin, in addition to vitamin B2, include B2-400 and B Complex Vitamin. In its chemical form, riboflavin is yellow-orange with poor solubility. It appears bright yellow in the urine when taken in excess and is colorless in its reduced form.

Riboflavin is often used in combination with other B vitamins in the vitamin B complex that includes vitamin B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B12 (cyanocobalamin), and folic acid. All B vitamins help the body convert carbohydrates into glucose to produce energy and aid in metabolizing fats and protein. All B complex vitamins are also water soluble and are not stored by the body.

Riboflavin also works as an antioxidant, fighting injurious particles called free radicals. These free radicals can damage cells, contribute to the development of conditions such as heart disease and cancer, and speed up the aging process. By fighting free radicals, riboflavin can reduce or help prevent some of the damage they cause.

In particular, vitamin B2 has been shown to be important for normal vision. Early studies indicate that riboflavin might help prevent damage to the lens of the eye, cataracts, and glaucoma. Taking riboflavin has also shown potential to reduce migraine headaches and to treat hyperhomocysteinemia (overly high amounts of homocysteine in the blood), though research is not conclusive. The only condition for which riboflavin is proven effective is riboflavin deficiency, which can cause anemia, skin disorders, mouth sores, and other symptoms. In tandem with other B vitamins, riboflavin has also been investigated in treating the following: red cell aplasia; hyperhomocysteinemia; sickle cell anemia; canker sores; cervical cancer; acne, dermatitis, eczema, and rosacea; carpal tunnel syndrome; eye fatigue; cataracts; glaucoma; liver disease; alcoholism; memory loss; Alzheimer’s disease; anxiety; epilepsy; multiple sclerosis; ulcers; burns. However, more research is required in these areas.

Riboflavin is available in multivitamins and B-complex vitamins and also comes in 25 mg, 50 mg, and 100 mg tablets. Since the recommended dose of riboflavin varies per person and medical condition, it is essential to consult with a health-care professional to determine the proper dose.

Overview

Recommended daily intakes for riboflavin and other nutrients are developed by the Food and Nutrition Board at the Institute of Medicine. The board’s recommended dietary allowances (RDAs) for riboflavin are:

Males 14 years or older: 1.3 mg/day

Females 14 to 18 years: 1.0 mg/day

Females 19 years or older: 1.1 mg/day

Breastfeeding women: 1.6 mg/day

Pregnant women: 1.4 mg/day

Infants 0–6 months: 0.3 mg/day

Infants 7–12 months: 0.4 mg/day

Children 1–3 years: 0.5 mg/day

Children 4–8 years: 0.6 mg/day

Children 9–13 years: 0.9 mg/day

Since the processing of grains results in significant loss of vitamin B2, white flour, bread, and breakfast cereals are often enriched or fortified with riboflavin in the United States. Riboflavin is also added to pastas, baby foods, and meal replacement products and used as a food coloring agent. In whole brown rice, riboflavin is mostly retained, while free riboflavin is also naturally present in whole milk, egg whites, and egg yolks.

Most healthy people eating a well-balanced diet receive sufficient riboflavin. Some of the best dietary sources of riboflavin include: milk, eggs, organ meats, soy beans, spinach, broccoli, mushrooms, wild rice, whole grains, wheat germ, almonds, and brewer’s yeast. Riboflavin is destroyed by exposure to light; hence to protect riboflavin content, foods should be stored away from light and in nonclear containers. Since the vitamin can also be depleted in water, steaming foods preserves more riboflavin than boiling, soaking, or frying.

Riboflavin does not usually cause side effects; when ingested in high doses, however, riboflavin may cause diarrhea, excess urine, and yellow-orange urine.

Since riboflavin is plentiful in the food supply of the Western world, a deficiency of riboflavin (vitamin B2 deficiency) is uncommon. However, low riboflavin may result when dietary intake is insufficient (a primary deficiency) or when the body suffers from a condition that does not allow it to be absorbed or used (a secondary deficiency). Riboflavin deficiencies often occur in tandem with deficiencies in other water-soluble vitamins, as well as in the elderly and individuals with chronic alcoholism, liver disease, eating disorders, diabetes, and inflammatory bowel disease. According to the Celiac Disease Foundation, people following a gluten-free diet (i.e., do not eat enriched wheat foods) may suffer riboflavin deficiency. The cure for jaundiced babies has also been found to cause degradation of riboflavin and must be closely monitored.

Possible complications arising from a vitamin B2 deficiency include: sore or inflamed throat; mouth or lip sores; cracks at the corners of the mouth; red, sore, or burning tongue; complications in metabolism; itchy, burning, or bloodshot eyes; light sensitivity; cataracts; itchy, dry, peeling skin; wrinkled arms and face; split fingernails and toenails; anemia; impaired nervous system function; weakness or fatigue.

Treatment for a vitamin B2 deficiency involves consuming a diet with an adequate amount of riboflavin-containing foods and taking vitamin supplements with the recommended daily value for one’s age.

Bibliography

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Kuzniarz, M., et al. "Use of Vitamin Supplements and Cataract: The Blue Mountains Eye Study." American Journal of Ophthalmology. 132:1. (2001). Print.

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