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Riboflavin is the chemical name of vitamin B2. In the early 1920's, scientists believed there were two vitamins, vitamin B1 and vitamin B2. The earlier-discovered vitamin B1 could not cure the skin disease pellagra without the action of later-discovered vitamin B2. It took 14 years for chemists to be able to isolate and synthesize vitamin B2 independently of vitamin B1.
If you have ever noticed your urine after taking riboflavin, you probably saw a fluorescent yellow. The root word "flavin" refers to yellow color. The flavin group is joined to an alcohol group called ribital made from a sugar called ribose, so the entire vitamin molecule is known as riboflavin. Many of the enzymes the body uses riboflavin to make are called metallo-flavoproteins, combining riboflavin with iron or manganese.
As you know, every cell in the human body transforms food into energy, sometimes storing that energy as a molecule called ATP. In the human body, ATP is analogous to gasoline for a car. Every cell uses glucose and oxygen to make ATP.
Cells make two of the enzymes they use to transform ADP to ATP with the help of riboflavin. Without riboflavin, not a single cell in the human body can use oxygen and glucose for energy. But making energy is not the only way the body uses riboflavin:
The most useful riboflavin foods are algae and brewer's yeast. Riboflavin is also abundant in organ meats, such as brain, tripe (menudo), intestines, spleen, kidneys, pancreas (sweetbreads), and liver. Most North Americans don't care for any of these foods, so they get nearly all of their riboflavin from the vitamin supplements added to white flour for making commercial baked goods.
Cooking a riboflavin food doesn't break down the vitamin, but riboflavin is very sensitive to light. Diary companies all over the world have replaced clear glass bottles with opaque cardboard cartons for milk in part to protect the riboflavin inside it. Any food that you eat for its riboflavin content should be stored in a dark, cool place.
|Food||Mg Riboflavin in 200-Calorie Serving|
|Red Bull Energy Drink||23|
|Fortified Breakfast Cereal||4|
|Pokeweed, Fireweed, Sourdock, Spirulina, Seaweed||3|
|Ancho Peppers, Beet Greens, Bitter Gourd, Spinach, Watercress||2|
|Baby Food, Blueberries, Mung Bean Spouts, Egg White||1|
Since these foods have been measured in 200-calorie increments, it may be necessary to eat up to 8 servings of some of the vegetables listed to get the indicated amount of riboflavin. Here is another way to evaluate riboflavin content of foods:
|Almonds||1 ounce/28 grams||0.23|
|Asparagus (boiled)||6 spears||0.13|
|Beef (cooked)||3 ounces/84 grams||0.16|
|Bread, white (enriched)||1 slice||0.08|
|Bread, whole wheat||1 slice||0.06|
|Broccoli (boiled)||1/2 cup chopped (about 60 grams)||0.10|
|Cheddar Cheese||1 ounce/30 grams||0.11|
|Chicken, dark meat (roasted)||3 ounces/84 grams||0.16|
|Chicken, light meat (roasted)||3 ounces/84 grams||0.08|
|Egg (cooked)||1 large||0.27|
|Fortified cereal||1 cup||0.59 to 2.27|
|Halibut (broiled)||3 ounces/84 grams||0.08|
|Milk (nonfat)||1 cup/240 ml||0.34|
|Salmon (cooked)||3 ounces/84 grams||0.12|
|Spinach (boiled)||1/2 cup (about 60 grams)||0.21|
What happens when you don't get enough riboflavin?
Riboflavin deficiency was once thought to cause the skin disease pellagra, but later research revealed that riboflavin supplementation merely cured a condition caused by the toxins in moldy grains. There are real riboflavin deficiency diseases, however, that occur all over the world:
Most of the conditions are caused ariboflavinosis, a simple failure to get enough riboflavin in the diet.
Riboflavin deficiency can happen to anyone, but it is most common in people who drink too much alcohol and in people who suffer anorexia. Congestive heart failure, however, is usually treated with diuretics that flush vitamin B2 out of the bloodstream, ironically, weakening the heart muscle.
Pompe's disease results from a genetic mistake that prevents the formation of the enzymes that help muscles use the sugar storage muscle glycogen. Although Pompe's disease is not a condition you should attempt to diagnose or treat on your own, riboflavin supplementation is an important part of its treatment.
In addition to these problems, riboflavin deficiency and zinc deficiency usually occur at the same time. And anyone over 50 should consider taking a riboflavin supplement as part of a nutritional program for reducing the risk of cataracts.
How can you tell you are getting enough riboflavin? If your urine is neon yellow, your body is absorbing all the riboflavin it needs and excreting the rest. No other vitamin colors the urine. If your urine is usually yellow, chances are that you are getting enough:
|Recommended Dietary Intake (RDI) for Riboflavin|
|Adults||19 years and up||1.3||1.1|
|Pregnant Women||Any age||-||1.4|
|Breast-Feeding Mothers||Any age||-||1.6|
An Australian study of 2,900 men and women found that those who consumed the most riboflavin, about 2 mg a day, were up to 51% less likely to have an eventual need for cataract surgery than those who consumed the least riboflavin, about 0.1 mg a day.
One study found that 54 men and women who took 400 mg of riboflavin a day were less likely to suffer migraine attacks, and that the effect of taking riboflavin is cumulative. It takes about three months to "kick in." Scientists believe that riboflavin reduces the frequency of migraines by building up energy reserves in the brain, which makes it suitable for use with medications that relieve migraines through different mechanisms.
I recommend riboflavin supplements for anyone over 50, especially those concerned about the risk of cataracts. A complete-B supplement providing 2 mg of riboflavin a day is ideal.
Q. Are there any riboflavin side effects or riboflavin toxicity?
A. When the Food and Nutrition Board set the recommended daily intake (RDI) in 1998, it did not set an upper limit (UL). No riboflavin side effects have been reported even among people who take 400 mg of supplemental riboflavin daily over an extended period. There are theoretical reasons to believe that high-dose riboflavin could be toxic in people who take megadoses of chromium supplements or who do metalwork with chrome, but these concerns have only a theoretical basis.
Q. Is there any value to riboflavin added to shampoo?
A. No, there is no reason hair follicles would be especially deficient in riboflavin, and the hair itself cannot take up the vitamin.
Q. Is riboflavin the vitamin used to treat conjunctivitis?
A. No, you are more likely to get a good result from taking supplemental biotin, and avoiding consumption of raw egg yolks, which contain a protein that binds biotin.
Q. Can riboflavin dissolve cataracts once they occur?
A. No, but you may be interested in the reports on L-carnosine for this purpose.
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