About the Vitamin
Vitamin B is comprised of 8 different components, one of which is riboflavin. Riboflavin is water soluble, meaning that any excess amount of vitamin simply washes through the body. Because it is not stored in the body, eating foods each day that contain riboflavin is extremely important as the vitamins must be replaced each day.
Vitamin B2 benefits the diet by stimulating many different chemical reactions. It is primarily a coenzyme that is needed in reactions like oxidation-reduction, also known as a redox reaction. Redox reactions involve the production of energy through the transfer of electrons. Riboflavin as coenzyme FAD (flavin adenine dinucleotide) causes there to be metabolism of fats, proteins and carbohydrates.
Energy production in the body takes place through the electron transport chain. This is a movement of high energy electrons across membrane barriers in the inner part of the mitochondria to the outer compartment of the mitochondria. This process is called cellular respiration. Riboflavin in the form of coenzyme FAD is one of the transport chemicals that moves electrons and produces energy. In this chemical movement there is a release of energy that is used in glycolysis and cellular respiration.
Another derivative of riboflavin is a flavoprotein which uses a flavoenzyme. Flavoproteins are needed for the metabolism of vitamins including vitamin B6, niacin and folic acid. Consequently riboflavin deficiency can result in nutritional deficiencies of these vitamins as well as other dependent metabolic production.
One area a riboflavin coenzyme is needed is in the conversion of the amino acid, methionine that is formed from homocysteine. An increase in homocysteine may be a result of decreased B2 levels.
Vitamin B2 Deficiency
Deficiency of vitamin B2 is called arboflavinosis. This usually occurs in conjunction with other nutritional deficiencies. Symptoms of B2 deficiency can include a combination of cracked lips, bright red tongue, sore throat, inflammation of the tongue and skin, blood vessel formation in the whites of the eyes and reduction in red blood cell count. Red blood cells will appear to be normal size and have the normal amount of hemoglobin. The cell count is simply reduced due to the decrease in vitamin B2.
Pregnant woman may experience preeclampsia. This condition produces symptoms including high blood pressure, increased urine protein and swelling of extremities. This can become a very serious condition, eclampsia, where there is extreme high blood pressure, a high risk of blood loss and even death.
Due to decrease in nutritional sustenance, alcoholics are at increased risk of vitamin B2 deficiency. There may also be metabolic disorders associated with alcoholism that interfere with proper metabolism and utilization of riboflavin. Anorexia also presents with vitamin B2 deficiency due to inadequate nutrition, as do those who are lactose intolerant. Other disorders involving proper absorption of nutrients can also produce riboflavin deficiencies.
The reduction in mitochondrial oxygen metabolism seems to be connected to those with migraine headaches. Riboflavin precedes the production of flavocoenzymes needed for oxygen metabolism by mitochondria. Those with migraines have experienced reduced symptoms and lessening of pain when taking riboflavin as a supplement.
Vitamin B2 is needed for iron metabolism. A deficiency of vitamin B2 seems to inhibit iron absorption by either impeding iron use for the production of hemoglobin. Another possibility is that reduced vitamin B2 levels may increase loss of iron through the intestinal tract.
Good Food Sources
Recommended Daily Allowance:
Since vitamin B2 is a water soluble vitamin, there needs to be a daily source for riboflavin. The recommended daily allowance for riboflavin is 1.3 mg/day for men and 1.1 mg/day for women. In order to ensure adequate riboflavin levels nutritionally, many bread products sold in the United States have been enriched with riboflavin. Riboflavin can be destroyed by sunlight, so some foods are best stored in dark containers. For example, milk is best stored in a dark or opaque container to protect the amount of riboflavin present.
Good sources for vitamin B2 are:
- Fortified cereal
- Salmon or halibut
- Boiled spinach
The highest source of riboflavin is fortified cereal that contains between 0.59 mg and 2.27 mg depending on the brand of cereal. Milk contains 0.34 mg/cup and cheese contains 0.11 mg/ounce. One egg contains 0.27 mg/egg.
Since riboflavin is a water soluble vitamin there is little chance of toxicity. Excess is simply eliminated from the body. B complex vitamins can be taken to ensure adequate daily allowance of riboflavin, however, eating a diet rich in a wide variety of foods is the best way to ensure adequate amounts of vitamin B2.