Riboflavin

Daily Value: 1.7 milligrams

Good Food Sources: Poultry, fish, fortified grains and cereals, broccoli, turnip greens, asparagus, spinach, yogurt, milk, cheeses

Riboflavin will probably never bathe in the nutritional spotlight like vitamin C, magnesium and vitamin E. But a smattering of experts say that it's about time we give this nutrient, also known as vitamin B₂, its due.

"It's not fashionable per se, but you're going to be hearing more about it," says Jack M. Cooperman, Ph.D., clinical professor of community and preventive medicine at New York Medical College in Valhalla.

Emerging research shows that riboflavin can act as an antioxidant, potentially helping to prevent cancer and control cholesterol buildup by helping to tame harmful free radicals. Free radicals are naturally occurring renegade molecules that damage your body's healthy molecules by stealing electrons to balance themselves. Antioxidants neutralize free radicals by offering their own electrons and thus protect the healthy molecules from harm.

Riboflavin assists a number of important chemical processes in the body. Folate and vitamin B₆, for example, need riboflavin to undergo the chemical changes that make them useful. Amino acids are transformed by riboflavin into what are called neurotransmitters, chemicals crucial for thinking and memory. A shortage of red blood cells, which causes symptoms such as anemia, has been linked in some cases to a lack of riboflavin. "The key concept to remember here is that riboflavin is one of the essential B vitamins necessary for all sorts of chemical processes inside the body, such as helping to turn food into energy," says Dr. Cooperman.

Riboflavin deficiency can affect your vision, causing your eyes to become light-sensitive and easily fatigued. Other symptoms of deficiency include blurred vision and itching, watering, sore or bloodshot eyes. Severe dermatitis is another hallmark of riboflavin deficiency.

Fortifying cereals and flours with riboflavin began during World War II, when meats and dairy products, among the best sources of the nutrient, were rationed. But folks who choose to limit their dairy and meat consumption may still be at risk for deficiency. "We've done a study that shows there is a correlation between low milk intake and riboflavin deficiency, particularly among African-American youths," says Dr. Cooperman.

People who exercise regularly may not be getting enough riboflavin, either, since activity seems to help speed the vitamin's removal from the body.

Using Riboflavin Safely

There's no need to worry about a riboflavin overdose. Any excess of this particular vitamin is excreted from your system. And unlike most other vitamins, this one quickly lets you know that you've reached your saturation point. Two hours after taking a supplement containing riboflavin, your urine will turn bright yellow, says Dr. Cooperman.

Huge amounts of riboflavin, 2,000 times the Daily Value, have been known to cause kidney stones, but there is no reason to take this much.

Both oral contraceptives and alcohol seem to reduce your body's ability to absorb riboflavin. So if you use either, you might want to consider taking a B-complex vitamin to cover all the bases, says Dr. Cooperman.