Vitamin B2, also known as riboflavin, is an essential vitamin that participates in many biological reactions. It is commonly used as an effective supplement to treat riboflavin deficiency. In addition, research suggests it may help prevent migraine attacks, cataracts, bone loss, improve symptoms of depression, eliminate bloodborne pathogens, and provide many other health benefits.
Vitamin B2, or riboflavin, plays a vital role in the body. It is activated to produce the coenzymes flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), which are essential for many biological reactions, including those required to break down fats, proteins, and carbohydrates.
Vitamin B2 is crucial for maintaining the health of the mucous membranes, skin, eyes, liver, and nervous system.
It is also involved in the metabolism of other vitamins such as B3, B6, B9, and B12.
Major dietary sources of this vitamin include meat, poultry, fish, eggs, dairy products, broccoli, radishes, and fortified grains.
Vitamin B2 is also available in dietary supplements for people who want to take it regularly, whether to reduce migraines, prevent cataracts, or support the health of the skin, hair, and nails, among other reasons.
History of Vitamin B2
The term “riboflavin” is derived from the word “ribose,” a sugar that forms part of its structure, and “flavin,” a type of pigment that gives riboflavin its distinctive bright yellow color when oxidized.
English biochemist Alexander Wynter Blyth was the first to discover riboflavin in 1872 when he observed a yellow pigment present in milk.
However, riboflavin was not officially identified until the early 1930s by Paul Gyorgy, the same biochemist credited with discovering other B vitamins such as biotin and vitamin B6.
It wasn’t until 1939 that scientists were able to prove the importance of riboflavin-rich foods for health.
Researchers continue to explore the significance of including more vitamin B2-rich foods in the diet.
This points to its broad effects on health — from energy levels to disease prevention and beyond. Today, many foods are fortified with B vitamins to help prevent deficiencies and improve nutritional status in the general population.
How Vitamin B2 Works
Riboflavin plays a role in the metabolism of macronutrients and the production of other complex vitamins.
It is known to participate in redox (oxidation-reduction) reactions in metabolic pathways through its coenzyme forms FAD and FMN, derived from riboflavin, by acting as electron carriers.
Insufficient riboflavin intake is expected to disrupt intermediate steps of metabolism, resulting in specific functional consequences.
Vitamin B2 is also recognized for its antioxidant role, particularly in regenerating glutathione and preventing the formation of free radicals.
Additionally, it is involved in growth and development, especially during pregnancy for fetal development and during breastfeeding.
Benefits of Vitamin B2
Vitamin B2 offers numerous health benefits. It fights migraines, helps eliminate microbes and bacteria, supports cognitive function, combats cancer, and reduces seizures.
1. Eye Health
Increased dietary intake of riboflavin has been linked to a significant reduction in age-related cataracts in various studies.
There is a condition known as ectasia — a progressive thinning of the cornea — often as a side effect of laser eye surgery.
A combination of riboflavin with UVA radiation (corneal cross-linking) triggers a reaction that strengthens the cornea by producing thicker collagen fibers.
Multiple studies with follow-up periods of up to 6 years have shown disease stabilization and improvement with this treatment.
Collectively, the evidence suggests that riboflavin helps prevent cataracts and that its use with UV light helps halt the progression of keratitis and improve inflammatory eye conditions.
You may discuss with your doctor whether this strategy could be helpful in your case.
2. Fighting Migraines
Although the exact mechanism is still unclear, some scientists believe that mitochondrial defects — the cell’s energy center — in migraine sufferers may hinder energy delivery to the brain.
This might increase neuronal excitability and make the brain more responsive to migraine triggers.
Riboflavin has been suggested to reduce these mitochondrial defects.
Three studies involving over 100 adults showed that riboflavin supplementation helped prevent migraines.
Combining riboflavin with magnesium was also effective in another study involving 130 individuals.
However, two studies on 60 children found riboflavin ineffective for pediatric migraines.
Vitamin B2 supplementation appears to be a safe, low-cost, and effective method to prevent migraines in adults — though not in children.
You may consider riboflavin supplements as an addition to your treatment plan if recommended by your doctor.
3. Eliminating Microbes and Bacteria
UV-activated riboflavin (vitamin B2) damages the DNA of viruses, bacteria, and parasites, thereby reducing their growth and survival.
This technique can be applied to donated blood to prevent infection during transfusions.
Treating whole blood using this technology has reduced infections from:
Bacteria (e.g., E. coli, Staphylococcus aureus, Streptococcus pneumoniae)
Viruses (e.g., Hepatitis B, Ebola, Herpes Simplex, Poliovirus)
Parasites (e.g., Babesia microti, Leishmania donovani, Plasmodium falciparum, Trypanosoma cruzi)
In a clinical trial involving over 200 transfusion patients, this technology reduced cases of transfusion-transmitted malaria.
In another trial with 70 children undergoing frequent blood transfusions, the method reduced adverse reactions and excessive immune responses.
Importantly, this technology did not affect the survival of red blood cells and platelets.
It appears effective in killing bloodborne pathogens while preserving blood cell function.
4. Fighting Depression
In a study of 98 individuals, low blood levels of riboflavin were linked to depression.
Another study of over 6,500 adolescents found that riboflavin intake was associated with a lower incidence of depression — but only among girls.
In a clinical trial with 14 elderly individuals with depression, supplementing with vitamins B1, B2, and B6 alongside tricyclic antidepressants improved symptoms and cognitive function.
In another trial with 29 healthy young adults, mood improved after supplementing with the recommended daily allowance of 9 vitamins, including B2.
This mood enhancement was especially linked to increased blood levels of riboflavin and vitamin B6.
A study on 865 pregnant women showed that riboflavin intake was associated with lower rates of postpartum depression.
Taken together, the studies suggest that riboflavin may help prevent depression, especially in women.
You can speak with your doctor to see whether riboflavin supplementation may help — but never use it as a replacement for prescribed treatments.
5. Bone Health
In a study on individuals with high homocysteine levels, those who consumed the least riboflavin had a higher risk of bone fractures.
Similarly, another study on over 1,200 women found that those with certain genetic traits and low bone mineral density could benefit from increased vitamin B2 intake.
A study on over 5,300 older adults showed that higher dietary B2 intake was linked to greater bone mineral density in the neck.
In a very old study, feeding pregnant mice a riboflavin-deficient diet led to abnormal fetal development and skeletal deformities.
Riboflavin has also been shown to stimulate the development of osteoblasts (bone-forming cells) in lab studies.
These findings suggest that riboflavin supplementation may help prevent bone loss in at-risk individuals.
If this applies to you, speak with your doctor about whether it’s worth considering.
6. Enhancing Cognitive Function
Dietary intake of vitamin B2 was associated with improved cognitive test scores in a study involving 554 rural Kenyan schoolchildren.
Another study of 137 older adults found that higher B2 intake was linked to better mental performance.
Although the results are promising, evidence is not yet strong enough to support the use of riboflavin specifically for cognitive enhancement.
More clinical research is needed.
7. Fighting Cancer
Riboflavin intake (alongside vitamin B6) was associated with a reduced risk of colorectal cancer in a study of over 88,000 postmenopausal women.
Another study of over 6,500 people found higher B2 levels were linked to a reduced rate of proximal colon cancer but increased rates of rectal cancer in women.
A meta-analysis of 10 studies involving over 12,000 women showed a weak association between B2 intake and reduced breast cancer risk.
A study of over 41,000 individuals found that B2 intake was linked to lower lung cancer risk in smokers — but not in non-smokers or former smokers.
Similarly, another study of nearly 90,000 women found no connection between B2 levels and lung cancer.
A study on around 15,000 men found no link between B2 intake and prostate cancer or mortality.
In another study of 21 esophageal cancer cases from two regions in Iran with different cancer risk levels, daily vitamin B2 intake helped prevent cancer in most cases.
Overall, the evidence is mixed and mainly suggests that B2 may have a minor effect on cancer development.
More research is needed for conclusive results.
8 – Benefits of Vitamin B2: Reducing Cramps
Vitamin B2 (alongside other B vitamins) helped reduce the duration, intensity, and frequency of nighttime leg cramps in a clinical trial involving 28 elderly individuals.
However, a single small clinical trial is not sufficient evidence to confirm that riboflavin reduces cramps.
Larger and stronger clinical trials are needed to verify this preliminary finding.
9 – Benefits of Vitamin B2: Treating Anemia
Anemia results from various factors, including reduced red blood cell production, the inability to transport oxygen to the blood, and blood loss.
Is riboflavin good or bad for you if you have anemia?
Vitamin B2 is involved in all of these functions and helps prevent and treat cases of anemia.
Vitamin B2 is required for the synthesis of steroid hormones and the production of red blood cells.
It also helps transport oxygen to the cells and aids in iron mobilization.
When people suffer from riboflavin deficiency without enough vitamin B2 in their diet, they become more susceptible to anemia and sickle cell anemia.
Low levels of vitamin B2 are associated with poor oxygen utilization and problems in red blood cell production.
These conditions can lead to fatigue, shortness of breath, inability to exercise, and more.
Research indicates that vitamin B2 is also effective in helping to reduce high levels of homocysteine in the blood.
This condition occurs when a person is unable to convert the chemical amino acid found in the blood into amino acids that the body can use.
Vitamin B2 (riboflavin) supplements have been shown to help correct this condition and balance homocysteine levels.
10 – Benefits of Vitamin B2: Regulating Energy Levels
Riboflavin is a vital component of mitochondrial energy — the body’s energy factory.
The body uses vitamin B2 in the metabolism of food for energy and to maintain proper brain, nerve, digestive, and hormonal functions.
This is why riboflavin is very important for body growth and repair.
Without adequate levels of riboflavin, a deficiency occurs, and the molecules in foods that contain carbohydrates, fats, and proteins will not be properly digested or used to produce the energy that keeps the body functioning.
This type of physical energy is called ATP (or adenosine triphosphate), often referred to as the "currency of life." The primary role of mitochondria is to produce ATP.
Vitamin B2 is needed to break down proteins into amino acids and fats and carbohydrates into glucose.
This helps convert nutrients from food into usable physical energy, which supports a healthy metabolism.
Riboflavin is also necessary for regulating proper thyroid activity and adrenal gland function.
A deficiency in riboflavin may increase the chances of developing thyroid disease.
Additionally, riboflavin is beneficial for calming the nervous system, fighting chronic stress, and regulating hormones that control appetite, energy, mood, temperature, and more.
Foods Rich in Vitamin B2
Riboflavin can be found in many foods, but meat, eggs, and dairy products are particularly high in this vitamin. Vitamin B2 is often added to certain foods, such as cereals.
It’s good to know that a lot of the riboflavin content is lost when boiling food since vitamin B2 is water-soluble.
Therefore, it’s better to prepare it differently, for example, by grilling or steaming.
Since a balanced diet can prevent vitamin B2 deficiency diseases, here is a list of healthy foods to include in your meal plan:
1 – Beef
Beef, like all meat, is a great source of riboflavin.
Three slices of grilled tenderloin steak will provide 24% of your daily value of vitamin B2.
However, beef liver is a better option, as three slices provide 171% of your daily required amount of riboflavin.
2 – Chicken
Chicken meat is high in riboflavin.
If you eat three pieces of cooked chicken, you’ll get about 11% of your daily required amount of vitamin B2. On the other hand, three pieces of cooked chicken breast contain 6% of your daily requirement.
3 – Salmon
Three pieces of pink salmon provide 12% of your daily requirement of riboflavin.
This type of oily fish is also rich in vitamin B3.
Additionally, it’s an excellent source of vitamins B1, B5, B6, and B12.
4 – Shellfish
A 3-ounce serving of cooked clams provides 24% of your daily requirement of vitamin B2.
Being rich in iron and omega-3 fatty acids, they are very healthy — especially since they are mercury-free seafood.
Moreover, they contain other minerals and vitamins such as vitamin A, selenium, and potassium.
5 – Dairy Products
Dairy products are rich in riboflavin. One cup of plain yogurt provides 35% of your daily vitamin B2 requirement.
A cup of milk provides 29%, while 3 ounces of Swiss cheese provide 18% of the recommended daily riboflavin intake.
Dairy products are also sources of vitamin B1 and great sources of vitamin B12.
6 – Oats
Oats are rich in several vitamins and minerals, including manganese, phosphorus, and copper.
Sometimes, minerals and vitamins are added to oats.
Thus, they can be very high in some nutrients.
For example, one cup of fortified cooked oats contains 65% of your daily requirement of riboflavin.
7 – Asparagus
Asparagus is one of the foods rich in vitamin B2.
One cup of cooked asparagus provides 19% of your daily riboflavin requirement.
Being rich in vitamins A, C, K, and B9, this type of vegetable can offer several health benefits.
8 – Black-eyed Peas
Black-eyed peas contain a variety of vitamins and minerals. One cup of canned black-eyed peas provides 6% of the recommended daily riboflavin intake, making this type of legume a good source of vitamin B2.
Other nutrients they offer include vitamin B9, iron, and magnesium.
Black-eyed peas are also a rich source of protein and fiber.
9 – Foods Rich in Vitamin B2: Apples
There’s a saying: an apple a day keeps the doctor away.
There are many truths about this fruit. One large apple with its peel provides 6% of the recommended amount of vitamin B2.
Moreover, apples are rich in fiber and vitamin C.
Potassium is another healthy nutrient you get from eating apples.
10 – Foods Rich in Vitamin B2: Grapes
Just 10 grapes provide 69% of the recommended daily value of riboflavin.
So grapes are definitely foods rich in vitamin B2.
Additionally, they are packed with fiber and are a great source of manganese, an important antioxidant.
11 – Foods Rich in Vitamin B2: Avocados
Avocados are foods rich in vitamin B2.
One avocado gives you 20% of your daily requirement for this vitamin.
Besides riboflavin, avocados contain other B vitamins such as B5, B6, and B9.
They are also rich in vitamin C, vitamin E, and vitamin K.
Moreover, this fruit is an excellent source of potassium and copper.
12 – Foods Rich in Vitamin B2: Spinach
Spinach is a leafy green vegetable full of vitamins and minerals.
Besides being a rich source of vitamins A, C, and B9, it is also among the sources of vitamin B2.
One cup of raw spinach provides 6% of your daily requirement for riboflavin.
13 – Foods Rich in Vitamin B2: Mussels
Three ounces of cooked mussels provide over 20% of your daily requirement of riboflavin.
They are also rich in other B vitamins and some important minerals such as iron and magnesium.
Mussels are an excellent source of omega-3 fatty acids.
Vitamin B2 Deficiency (Riboflavin Deficiency)
Riboflavin deficiency is rare because it is widely available in a variety of food options.
However, individuals who follow diets low in milk and meat — two of the best sources of riboflavin — may be at risk.
Additionally, certain specific groups of individuals may be more prone to deficiency.
Major Sources of Riboflavin
Milk and dairy products are very rich in riboflavin.
In Western diets, dairy consumption is the main source of vitamin B2, making riboflavin deficiency uncommon among water-soluble vitamins.
However, in developed countries, there is an increasing amount of semi-skimmed milk, where the riboflavin content has been depleted.
Although riboflavin is relatively stable, it degrades easily when exposed to light. Milk stored in glass bottles can be vulnerable to nutrient loss due to light exposure.
Grain products naturally contain low levels of vitamin B2, but fortification practices have ensured that some types of bread and cereals have become sources of riboflavin.
Therefore, according to one study, high levels of riboflavin were found in those who eat cereals for breakfast.
Fatty fish are also excellent sources of riboflavin, and some fruits and vegetables — especially dark green vegetables — contain reasonably high concentrations.
Vegetarians who have access to a variety of fruits and vegetables can avoid riboflavin deficiency.
Although their intake may be lower than that of meat-eaters, elderly vegetarians are indeed at greater risk for this deficiency.
Mild riboflavin deficiencies can exceed 50% of the population in third-world countries and refugee situations.
The deficiency is uncommon in the United States and in other countries that consume bread, pasta, cornmeal, or enriched rice.
In the United States, beginning in the 1940s, flour, cornmeal, and rice were fortified with B vitamins to restore some of what was lost during milling, bleaching, and other processes.
For adults aged 20 years or older, the average intake from food and beverages is 1.8 mg/day for women and 2.5 mg/day for men.
An estimated 23% of people consume dietary supplements containing riboflavin, providing an average of 10 mg.
People at Risk of Riboflavin Deficiency
1. Vegetarian Athletes
Physical exercise causes stress on metabolic pathways that use riboflavin.
The Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine state that vegetarian athletes are at risk of riboflavin deficiency due to their increased need for this nutrient and because some vegetarian athletes exclude all animal products (including milk, cheese, and eggs), which tend to be good sources of riboflavin, from their diets.
These organizations recommend that vegetarian athletes consult a sports nutritionist to avoid this potential issue.
2. Pregnant and Breastfeeding Women
Pregnant or breastfeeding women who rarely consume meat or dairy products (such as those living in developing countries and some vegetarians in the U.S.) are at risk of riboflavin deficiency, which can have adverse effects on both maternal and child health.
Riboflavin deficiency during pregnancy, for example, may increase the risk of preeclampsia.
Riboflavin intake during pregnancy is positively associated with birth weight and length.
Mothers with riboflavin deficiency or low dietary intake (less than 1.2 mg/day) during pregnancy are at greater risk of deficiency and some birth defects (such as gastrointestinal and cardiac defects) in the fetus.
However, riboflavin intake is not related to the risk of oral clefts in infants, as some claim.
In well-nourished women, riboflavin concentrations in breast milk range from 180 to 800 micrograms/liter.
Riboflavin levels in breast milk increase over time.
In developing countries, by contrast, riboflavin levels in breast milk range from 160 to 220 micrograms/liter.
3. Vegetarians
For people who consume meat and dairy products, these foods contribute a significant portion of dietary riboflavin.
For this reason, people living in developing countries who consume limited amounts of meat and dairy are at higher risk of riboflavin deficiency.
Vegetarians and those who consume little milk in developed countries are also at risk of riboflavin deficiency.
4. People with Brown-Vialetto-Van Laere Syndrome
Brown-Vialetto-Van Laere syndrome is an extremely rare neurological disorder that can begin at any age and is associated with deafness, paralysis (motor neuron disease), and breathing difficulties.
The condition is caused by mutations in the SLC52A3 gene, which encodes the intestinal riboflavin transporter.
As a result, these patients suffer from riboflavin deficiency. Riboflavin supplements can be life-saving in this group.
Causes of Vitamin B2 Deficiency
Riboflavin is continuously excreted in the urine of healthy individuals who do not have kidney disease or other illnesses, making deficiency relatively common when daily intake does not meet the body’s needs.
Riboflavin deficiency usually coexists with deficiencies in other nutrients and vitamins, particularly water-soluble ones.
Riboflavin deficiency may be primary, due to a diet poor in riboflavin-rich foods, or secondary, due to conditions that affect absorption in the intestines, the body’s inability to use the vitamin, or increased excretion of the vitamin.
Deficiency has also been observed in women taking oral contraceptives, the elderly, individuals with eating disorders, chronic alcoholics, and those with diseases such as HIV, inflammatory bowel disease, diabetes, and chronic heart disease.
According to the Celiac Disease Foundation, following a gluten-free diet — which excludes wheat flour and bread — may be low in riboflavin (and other nutrients), as enriched wheat flour and wheat-based foods (bread, pasta, cereals, etc.) are major contributors to riboflavin intake.
Phototherapy used to treat jaundice in infants can lead to increased riboflavin degradation, resulting in deficiency if not carefully monitored.
Symptoms of Vitamin B2 Deficiency
Riboflavin deficiency (also called ariboflavinosis) leads to inflammation of the mouth, including a painful red tongue, sore throat, cracked lips, and inflammation of the corners of the mouth (angular stomatitis).
There may be a scaly rash on the scrotum, vulva, lip covering, or nasolabial folds.
The eyes may become red, watery, bloodshot, and sensitive to light.
Due to impaired iron absorption, mild to moderate riboflavin deficiency causes normocytic normochromic anemia (normal-sized red blood cells and normal hemoglobin content), which differs from the anemia caused by folic acid (B9) or cyanocobalamin (B12) deficiency, where the red blood cells are large (megaloblastic anemia).
Riboflavin deficiency during pregnancy can lead to congenital defects including heart defects and limb malformations.
Prolonged riboflavin deficiency is also known to cause deterioration of the liver and nervous system.
The symptoms of stomatitis resemble those seen in pellagra, which is caused by niacin (B3) deficiency.
Treatment of Vitamin B2 Deficiency
Treatment involves a diet that includes sufficient riboflavin-containing foods.
Most multivitamin and mineral supplements contain 100% of the daily value of riboflavin and can be used by individuals with inadequate diets.
Riboflavin supplements are available over the counter in the U.S. in doses up to 100 mg, but there is no evidence that these high doses provide any additional benefit for healthy individuals.
The Role of the Medical Team in Riboflavin Deficiency
The body does not store riboflavin in large amounts; only small reserves exist in the liver, heart, and kidneys.
Most people get riboflavin from their diet, but many individuals follow restricted diets or do not consume dairy products — making them vulnerable to riboflavin deficiency.
Other risk factors for riboflavin deficiency include pregnancy, poverty, aging, depression, breastfeeding, phototherapy use, and cognitive decline.
Riboflavin deficiency can present with a wide range of clinical symptoms; thus, in light of these facts, a team of doctors and healthcare providers is required to prevent this nutritional deficiency.
Pharmacists play an important role in educating patients as they are on the front lines and can also provide dosage recommendations to prescribing physicians based on the situation at hand.
Dietitians should emphasize the importance of proper nutrition, exercise, and maintaining a healthy weight.
Nurses also play a key role in educating pregnant mothers about the risk of riboflavin deficiency during breastfeeding and the need for supplements.
Nurses caring for newborns receiving phototherapy for hyperbilirubinemia or jaundice should be aware that this treatment can also cause riboflavin deficiency, thus necessitating supplementation and physician alert.
For outpatients, a dietitian or pharmacist should be consulted to educate patients on riboflavin-rich foods.
