Vitamin B2—Riboflavin

Posted by Blog Tuesday, March 1, 2011

 The Fat Burner
Riboflavin was discovered as a growth factor in the early nineteenth century. Riboflavin has a greenish-yellow color, which led to one of its early names, vitamin G. In 1935, riboflavin was first synthesized in the lab, and by 1938, its structure was determined. When it is taken in excess of needs, riboflavin is responsible for the bright yellow color of urine.

Riboflavin does its primary work as part of a coenzyme named Flavin Adenine Dinucleotide (FAD). Coenzymes derived from riboflavin are called flavins. Flavins are needed for the metabolism of carbohydrates, fats, and proteins. One of the ways that the thyroid gland controls metabolism is by regulating riboflavin’s coenzyme activity. FAD is needed to prepare fatty acids for energy production in the mitochondria of all cells, as seen in Figure -5

Flavins derived from riboflavin play a vital role in the metabolism and elimination of toxins, drugs, carcinogens, and steroid hormones. One flavin, the coenzyme FAD is also needed in the reduction and oxidation cycle of glutathione, as shownin Figure -6. This glutathione reduction and oxidation cycle has a major role in protecting us from free radicals such as hydrogen peroxide. When glutathione protects us from free radical oxidation, it becomes oxidized. FAD is needed to reduce (recharge) the glutathione and return the glutathione to its protective state.

 Riboflavin deficiency is associated with the increased oxidative stress that can be caused by free radicals. A deficiency of riboflavin will reduce the efficiency of glutathione, an important antioxidant. In fact, measurement of glutathione reductase activity in red blood cells is used to assess the nutritional deficiency of  riboflavin. Another coenzyme made from riboflavin is Flavin MonoNucleotide (FMN). FMN is needed for the activation of pyridoxine (vitamin B6). This is one of the

Figure -5 Riboflavin as FAD helps to prepare fats for energy production.

Figure -6 Riboflavin’s role in antioxidant protection.

reasons that it is best to take all of the B vitamins together. A deficiency of riboflavin prevents the activation of pyridoxine, so taking pyridoxine by itself is not a good idea. Riboflavin in the forms of FMN and FAD coenzymes is also required by the mitochondrial electron transport chain for energy metabolism, as seen in Figure -7. Riboflavin is also needed by the tricarboxylic acid (TCA) cycle during energy production. This cycle has also been known as the Krebs cycle.

Riboflavin Coenzyme forms are:
Flavin Adenine Dinucleotide (FAD)
Flavin MonoNucleotide (FMN)

Figure -7 Riboflavin is needed for energy production in the cell.

No specific disease is caused by riboflavin deficiency. However, riboflavin deficiency can cause inflammation of the membranes of the eyes, the mouth, the skin, and the gastrointestinal tract. This condition is called ariboflavinosis (the prefix “a-” means without and the suffix “-osis” means disease). Riboflavin deficiency also can cause sensitivity to light. Cracks on the side of the mouth are another possible sign of riboflavin deficiency.

The best sources for riboflavin are whole grains and green leafy vegetables; please refer to Graph 2. Spinach, broccoli, chard, and asparagus are all rich sources of riboflavin. Almonds and soybeans are good sources. Dairy products have large amounts of riboflavin. Nutritional yeast is high in riboflavin and many other nutrients.

Graph 2 Riboflavin amounts in some common foods

Riboflavin is found in supplements in the form of riboflavin and in the form of riboflavin monophosphate. In supplements, riboflavin is most commonly found in vitamin B-complex preparations and in multivitamins.
Summary for Riboflavin—Vitamin B2

Main function: energy metabolism.

RDA: men, 1.3 mg; women, 1.1 mg.

No toxicity reported, no upper intake level set.

Deficiency condition: ariboflavinosis.

Healthy food sources: whole grains and leafy green vegetables.

Degradation: easily destroyed by light, especially ultraviolet light.

Coenzyme forms: Flavin Adenine Dinucleotide (FAD) and Flavin MonoNucleotide (FMN).

Synthetic riboflavin used in supplements and fortified foods and drinks is very likely to have been produced using genetically modified Bacillus subtilis. These bacteria have been altered to increase the bacteria’s production of riboflavin. The genes of the bacteria may also have been altered by the addition of antibiotic resistance to ampicillin. This is one possible difference between synthetic and naturallyoccurring  riboflavin.

Heat does not normally degrade riboflavin. However, ultraviolet light and other forms of irradiation including visible light destroy riboflavin, as shown in Figure-8.

Figure -8 Riboflavin is destroyed by light and UV light.

More about B-Vitamins:

B Vitamins The Energy Vitamins


Vitamin B1—Thiamin

Vitamin B2—Riboflavin

Vitamin B3—Niacin

Vitamin B5—Pantothenic Acid

Vitamin B6—Pyridoxine

Vitamin B12—Cobalamin

How the B Vitamins Make Energy Production Possible

”Wanna B” Vitamins That Might Not Be Vitamins


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