Katie Arlinghaus
KNH 413; Matuszak
Nutrient Fact Sheet
April 24, 2014
Medical Nutrition Therapy Nutrient: Riboflavin
1. What is the nutrient?
Riboflavin (vitamin B2)
2. What is the RDA/DRI for the nutrient?
Infants (AI):

0 - 6 months: 0.3* milligrams per day (mg/day)

7 - 12 months: 0.4* mg/day
Children (RDA):

1 - 3 years: 0.5 mg/day

4 - 8 years: 0.6 mg/day

9 - 13 years: 0.9 mg/day
Adolescents and Adults (RDA):

Males age 14 and older: 1.3 mg/day

Females age 14 to 18 years: 1.0 mg/day

Females age 19 and older: 1.1 mg/day
3. How is the nutrient metabolized?
Riboflavin is absorbed in the small intestine and undergoes ATP-dependent
phosphorylation catalyzed by cytosolic flavokinase to form FMN, which is further
converted to FAD to enable it to enter the plasma. In the plasma, free riboflavin is bound
to albumin and immunoglobulins for transport. Riboflavin is important for metabolism in
the form of cofactors FMN and FAD.
4. What are food sources of the nutrient?
Riboflavin is found in:

dairy products, milk

eggs

leafy green vegetables

lean meats

legumes

nuts

fortified breads and cereals
*Riboflavin is destroyed by exposure to light. Therefore, it is important to store foods
containing riboflavin in containers that prevent light exposure (not glass).
5. What disease states alter the nutrient’s metabolism?
Riboflavin deficiency interferes with the metabolism of other B vitamins, especially B12,
B6, and folate. Promising research is being done on its role in potentially preventing
cardiovascular diseases, cancers, and impairments in vision.
6. What are the tests or procedures to assess the nutrient level in the body?
Riboflavin deficiency can be diagnosed with a test on the red blood cells that measures
the activity of glutathione reductase. A riboflavin derivative is added to the red blood
cells. In normal riboflavin levels, the stimulation from the riboflavin derivative is less
than 20%. Anything higher than 20% is considered to be characteristic of a riboflavin
deficiency.
7. What is the drug –nutrient interactions?
There are no major known drug interactions with riboflavin to be concerned about.
Minor reactions include:

Drying medications might increase the amount of riboflavin that is absorbed

Depression medications might decrease the amount of riboflavin in the body

Phenobarbital may increase the rate that riboflavin is broken down

Probenecid may increase the amount of riboflavin in the body.
8. How is the nutrient measured?
Riboflavin is measured in mg.
9. What is the Upper Tolerable Limits?
Riboflavin is a water-soluble vitamin so any excess is excreted through the urine.
Therefore, an Upper Tolerable Limit has not been established.
10.What are the physical signs of deficiency?
Deficiency symptoms include:

anemia

mouth or lip sores

skin disorders

sore throat

swelling of mucus membranes
11.What are physical signs of toxicity?
Riboflavin is a water-soluble vitamin so any excess is excreted through the urine. There is
no known toxicity of riboflavin. Urine may be yellow with excess riboflavin consumption.
Resources:
Powers, Hilary. "The American Journal of Clinical Nutrition." Riboflavin (vitamin B-2) and
health. N.p., n.d. Web. 14 Apr. 2014. <http://ajcn.nutrition.org/content/77/6/1352.full>.
"Riboflavin (Vitamin B2) Effectiveness, Safety, and Drug Interactions on RxList." RxList. N.p.,
n.d. Web. 14 Apr. 2014.
<http://www.rxlist.com/riboflavin_vitamin_b2/supplements.htm>.
"Riboflavin: MedlinePlus Medical Encyclopedia." U.S National Library of Medicine. U.S.
National Library of Medicine, n.d. Web. 13 Apr. 2014.
<http://www.nlm.nih.gov/medlineplus/ency/article/002411.htm>.