If you take a multivitamin that contains riboflavin, you may have noticed that your urine takes on a yellow-green glow soon after you pop the supplement. Whenever an excess of this B vitamin is excreted, you’re likely to detect that mysterious glow. Riboflavin does more than produce psychedelic urine, however. It is a key player in the body’s production of energy from fat, carbohydrates, and protein. It also helps our bodies produce glutathione, which acts as an antioxidant by protecting us from the cellular damage that can lead to cancer and heart disease.
Riboflavin is also needed to help several other B vitamins go about their work. It changes vitamin B6 into a form that the body can use, and it helps change the amino acid tryptophan into niacin, another essential B vitamin. "Even though we often focus on riboflavin’s role in energy metabolism, it plays several other important roles throughout the body," says Donald McCormick, Ph.D., chairman of the department of biochemistry at Emory University in Atlanta.
Energy Relay
Like many of the other B vitamins, riboflavin helps us generate energy. Inside the mitochondria, a cell’s tiny powerhouse, riboflavin acts as a kind of shuttle bus. It helps to move electrons derived from the foods we eat along a pathway called the electron transport chain. As the electrons are passed along, they release energy.
The energy is used to make a molecule called ATP that acts as the cell’s basic energy currency. It is used extensively throughout our bodies any time energy is needed—to move muscles, make protein, and digest food. When it’s in short supply, all body functions slow down, and we feel less energetic.
In addition, riboflavin seems to have the power to control migraines. While it’s unlikely to rival aspirin as a headache stopper, researchers have noted that people with an inherited disorder that includes migraine headaches showed improvement with the supplement. "These people have fewer, less severe headaches when they get additional riboflavin," says Marc Lenaerts, M.D., a neurologist at the University of Oklahoma Health Sciences Center in Oklahoma City.
Given the results of these studies, "we decided to study the effects of additional riboflavin in people with ‘normal’ migraines," Dr. Lenaerts says. Their first study with migraine sufferers showed a 68 percent reduction in headache symptoms among people who took riboflavin. Another study four years later included a second group that was given an inactive substance (a placebo) instead of riboflavin; it was more carefully controlled to account for a possible placebo effect. It showed 37 percent fewer migraines, plus less nausea and vomiting, in people who took 400 milligrams of riboflavin a day as one daily dose.
"This improvement is similar to what can be achieved using conventional preventive migraine drugs," Dr. Lenaerts says. He’s hoping to do more studies to confirm this benefit of riboflavin for migraine sufferers and to determine if a lower dose might be just as helpful.
SUPPLEMENT SNAPSHOT
| Riboflavin Supplement form: Riboflavin-5-phosphate; also known as vitamin B2. May help: Migraine headaches, cataracts, and sickle-cell disease. Daily Value: 1.7 milligrams. Special instructions: Since riboflavin is destroyed by light, buy milk in cardboard containers. A translucent plastic jug of milk sitting in a lighted dairy case for just one day can lose up to 70 percent of its riboflavin. Who’s at risk for deficiency: The elderly, who tend to eat fewer riboflavin-containing foods; people who are exercising and dieting; people who don’t drink milk; alcoholics; those who are undergoing dialysis or taking diuretics, antibiotics, or barbiturates; and people with intestinal problems that interfere with absorption. Good food sources: Eggs, lean meat, milk, broccoli, and enriched breads and cereals. Cautions and possible side effects: May cause photosensitivity at high dosages (more than a few milligrams a day). |
Free Radical Rounder-Upper
Riboflavin also helps our bodies make glutathione, a free radical scavenger that’s produced by cells. Some people simply can’t produce glutathione because of an inherited abnormality, and they have a marked increase in cell damage. Red blood cells break down more easily, while white blood cells and nerves are also affected. With more riboflavin to support the production of glutathione, it seems reasonable to assume that people would experience less cellular damage.
Animal research has led some scientists to believe that people who are deficient in riboflavin are more likely to develop cataracts, because glutathione helps to protect the eyes from damage by sunlight.
In one study on animal tissue, researchers found that riboflavin can help protect tissues from damage from oxygen that occurs when blood flow stops, then starts again. That stop-start pattern is exactly what develops when someone has a heart attack or stroke.
People with sickle-cell disease, in which misshapen cells occasionally clog blood vessels, may also benefit from additional riboflavin. In one study, people with sickle cell disease who were given five milligrams of supplemental riboflavin twice a day for eight weeks showed significant improvements in their health profiles.
Who Needs More?
The Daily Value for riboflavin is 1.7 milligrams, and most people get all that and more from the foods they eat, Dr. McCormick says.
The majority of people who seem to benefit from extra riboflavin, such as those with migraine headaches, may be relatively riboflavin-deficient because of the way their cells work, not because their food sources are letting them down, says Dr. Lenaerts.
Some people don’t get enough riboflavin and other B vitamins simply because they don’t eat well. These include alcoholics, elderly people who don’t eat enough calories, and people who have sworn off dairy products, eggs, or meat. The lack of dairy foods is particularly telling, since most people get about half of their daily riboflavin from milk and milk products. Vegans (strict vegetarians) can obtain ample riboflavin in their diets, especially if they include dark green vegetables. They can also get additional riboflavin from nutritional yeast, which is another good source.
People with intestinal problems that interfere with absorption and people undergoing dialysis may show symptoms of riboflavin deficiency.
Long-term use of some antibiotics can increase riboflavin excretion, and a class of psychiatric drugs called phenothiazines, which includes Thorazine, can interfere with the body’s ability to use riboflavin, Dr. McCormick says. People who are taking these drugs may need supplementation.
Classic deficiency symptoms include cracks and redness at the corners of the mouth; a painful, smooth, purplish-red tongue; inflamed eyelids and sensitivity to light; and an unsightly skin rash called seborrheic dermatitis.
Shortages of other B vitamins can also cause these symptoms, and riboflavin deficiency can cause shortages of other B vitamins, notably B6. If you suspect that you have a riboflavin deficiency, it’s best to make sure that you’re getting enough of all the B vitamins, Dr. McCormick says. If you do have a deficiency, your doctor may advise you to take supplements, he adds.
You need to be careful not to overdo it, however, since taking too much has the potential to cause photosensitivity. "If your body is saturated with riboflavin and you’re sitting out in the sun, there is the possibility of injury to your skin or eyes," Dr. McCormick says.
