Vitamin B2

What is Vitamin B2?

Vitamin B2, also known as Riboflavin is one of the 8 B vitamins which makes up the B complex family. Vitamin B2 is water-soluble which means your body does not store it and can be rapidly depleted.

One of the main functions of all the B vitamins is converting carbohydrates into glucose which helps the body produce energy. The B-complex vitamins are important for the health of skin, hair, eyes and the liver. Many of the B-complex vitamins also play an important role in keeping the nervous system healthy and the brain functioning properly.

Vitamin B2 is needed for the functioning of every single cell within your body acting as an antioxidant maintaining many functions within the body.

If you take certain B complex supplements you many notice your urine turning yellow. Vitamin B2 is one of the yellow colored B vitamins and is the one responsible for making your urine yellow.

It is important for body growth, red blood cell production, protecting skin and eye health as well as having numerous health benefits within the body. Vitamin B2 also assists with release of energy from proteins.

Riboflavin is needed to help the body convert vitamin B6 and folate into forms that can be used. It is essential for growth and red blood cell production.

Health Benefits of Vitamin B2

Riboflavin is a well-absorbed water-soluble vitamin and has an important role to play in maintaining overall health with many health benefits described below:

Migraine Headaches

Vitamin B2 in high doses may help migraine sufferers and are not often prescribed to prevent severe migraines. One study carried out in 1998 showed that a dose of 400mg had been used effectively to reduce migraines. Supplementation with Riboflavin in people suffering from Migraine Prophylaxis has shown to reduce the frequency and duration of migraine attacks without any adverse side effects. People who suffer from migraines may not have enough Vitamin B2. Alcoholics will also suffer from migraines as it depletes most the B complex vitamins. [1] [2]

Boosts Energy Production

Riboflavin plays a major role in how the body gets energy from carbohydrates, fats, and proteins. Riboflavin assists in the metabolism of these very essential macronutrients and helps boost energy production as a result.

It is essential for breaking down proteins, fats, and carbohydrates.

Increases Blood Circulation

Vitamin B2 is essential for the growth and production of red blood cells and antibodies. This new growth of red blood cells and antibodies increases blood circulation and increases oxygen levels to circulate to various organs of the body.

Promotes Growth & Development

Vitamin B2 is essential for normal growth as it helps to break down some of the essential macronutrients which includes carbohydrates, fats and proteins.

Riboflavin contributes to proper growth and development of the reproductive organs, and the growth of body tissues such as the skin, connective tissue, eyes, mucous membranes, nervous system and the immune system. It plays a key role in healthy skin, nails, eyes, mouth and hair.

Regulates Thyroid Activity

Vitamin B2 is needed to regulate thyroid activity and adrenal function and a deficiency of the vitamin can be linked to thyroid disease. Vitamin B2 is also one of the most common vitamin deficiencies seen in hypothyroidism. A deficiency of riboflavin may be a causative factor in Thyroid Eye Disease.

Skin Care

Vitamin B2 is useful in preventing certain conditions of the skin such as acne, dermatitis, and eczema as it helps to improve the mucus secretion of the skin which can help to clear the skin.

Repairs Tissues and Promotes Wound Healing

Vitamin B2 plays an important role in the repair of tissues and promote the healing of wounds and other injuries to heal more quickly.

Protects Nervous System

Vitamin B2 can help in treating disorders of the nervous system such as Alzheimer’s disease, multiple sclerosis, anxiety, epilepsy and Carpal Tunnel Syndrome. These disorders are primarily helped by taking Vitamin B6 as well as other vitamins. Vitamin B2 is needed by the body to convert vitamin B6 and folate into forms it can use.

Patients suffering from neurological conditions have been linked to certain vitamin B deficiencies which includes vitamin B2. [3] [4]

Protects Vision

Vitamin B2 along with other essential nutrients plays a major role in ensuring healthy eyes and clear vision.

Some studies suggest that vitamin B2 is also helpful in cataract and glaucoma prevention and reduce symptoms.

In one study people who took a niacin and riboflavin supplement had fewer cataracts. [5] [6]

Prevents HIV/AIDS

A study done on a selected group of men with the HIV-1 infection have shown to have a deficiency of Vitamin B2 (Riboflavin) suggesting that various nutrients can slow down the progression of HIV and avoid the risk of progressing into the AIDS virus. Vitamin B2 has also been used for lactic acidosis brought on by treatment with medications for AIDS called NRTI drugs. [7]

Prevents rheumatoid arthritis

Vitamin B2 can help to prevent rheumatoid arthritis. [8]

Boosts Vitamins and Mineral Absorption

Vitamin B2 can help in the absorption of vitamins such as B1, B3, and B6 as well as minerals such as iron, zinc and folic acid. Most of the B vitamins also work well together and are needed by the body. [9]

Protects Digestive Tract

Vitamin B2 helps the digestive system in absorbing iron which plays a major role in maintaining and protecting the mucous membranes in the digestive system. It keeps the mucous membranes in the mouth and bowels healthy and helps to speed up metabolism.

Boosts Immune System

Vitamin B2 has excellent antioxidant properties which can help to boost the immune system and strengthen antibodies which can help fight against infections. Since it also helps maintain healthy blood cells this also helps with the function of the immune system. It can help in removing free radicals and minimizes carcinogens that may play a role in cancer. This effect may also help in the prevention of heart diseases.


Vitamin B2 plays a very important role in the treatment of anemia as it has the ability to help absorb iron which is one of the main deficiencies in people with anemia. [10]


Abnormal levels of dicarboxylic acids found in the urine of autistic children can be significantly reduced with various nutrients which includes the supplementation of vitamin B2, Vitamin B6 and magnesium. [11]

Other uses for vitamin B2 include delaying the aging process, boosting athletic performance, promoting healthy reproductive function, canker sores, memory loss, alcoholism and liver disease.

Agonist / Synergist

Vitamins: A, B1, B3, B5, B6, B9, B10, B12


Vitamins: B1
Minerals: Ca, Cu, Fe, Mn, Na, Zn


Food Sources of Vitamin B2

There are many foods fortified with Vitamin B2 / Riboflavin such as bread and breakfast cereals.

Although most packaged food such as cereals are fortified with this vitamin it is best to derive the vitamin from a natural food source. The following are natural whole foods that contain Vitamin B2 / Riboflavin:

  • Meat - Grass-Fed Beef (or Lamb)
  • Dairy products (cheese, eggs, milk
  • Green leafy vegetables (seaweed)
  • Organ Meat (such as liver from lamb, beef, veal, turkey, or chicken and kidneys from beef and lamb)
  • Mollusks/ Cuttlefish
  • Mackerel Fish
  • Nuts and Seeds (Almonds, Sesame Seed / Tahini)
  • Tempeh – Fermented Soy
  • Beans and Legumes

The amounts recommended for vitamins and minerals are different for each country which can be found on the government website of host country. The nutritional data for each country are based on scientific research which are presented by the scientific academies in each country to help advise governmental departments for food and human nutrition.

Below is a list of some of the countries and the EU for which nutritional guidelines are available found on corresponding official government website (including the national academy of science website for the USA).


The  2015–2020 Dietary Guidelines for Americans -  Dietary Reference Intakes

Recommended Dietary Allowances and Adequate Intakes from Food and Nutrition Board, Institute of Medicine, National Academies

Dietary Reference Intakes (DRIs) Food and Nutrition Board, Institute of Medicine, National Academies

Dietary Reference Intakes (DRIs): Tolerable Upper Intake Levels (UL)


Dietary Reference Intakes includes Tolerable Upper Intake Levels


Nutrition Requirements

Safe Upper Levels (SULs) for Vitamins and Minerals

Australia and New Zealand

Nutrient Reference Values (NRVs) and Upper Level Intake 


Dietary Reference Values for nutrients

Tolerable Upper Intake Levels For Vitamins and Minerals

Vitamin B2 Supplementation

As a supplement it is used to treat and prevent thiamine deficiency and disorders associated with it. It is taken by mouth and is available in capsule or powder form as well as tablets. Riboflavin is a water soluble vitamin like all B vitamins which is excreted rapidly through the urine. Because the body does not store this vitamin it is important for a daily intake through a healthy diet in or to avoid a riboflavin deficiency. Riboflavin is destroyed by exposure to light. Any supplements or foods with riboflavin should not be stored in clear containers and exposed to light.

Riboflavin supplements can increase iron absorption which may help those suffering from anemia.

Taking riboflavin supplements with food can increase absorption of this vitamin.

Riboflavin facilitates copper metabolism and therefore slows the thyroid. Supplementation of riboflavin without copper may deplete copper and can promote hyperthyroidism.

Deficiency Symptoms of Vitamin B2

There are many packaged foods fortified with Vitamin B2 / Riboflavin that now contain various amounts that most people usually do not suffer a deficiency of this vitamin.

Vitamin B2 deficiency is not common in developed countries as many refined carbohydrates are fortified this vitamin. Many of the food sources of vitamin B2 are also common in most nations such as eggs and meat.

The following symptoms are signs of a Vitamin B2 deficiency:

  • Anemia
  • Fatigue
  • Impaired nerve function
  • A sluggish metabolism
  • Mouth or lip sores or cracks
  • Skin inflammation and skin disorders, especially around the nose and face
  • Inflamed mouth and tongue
  • Sore throat
  • Swollen tongue
  • Swelling of mucus membranes
  • Changes in mood, such as increased anxiety and signs of depression
  • Itchy eyes and eyelids
  • Bloodshot eyes
  • High sensitivity to light
  • Burning sensation in the eyes
  • Parched lips
  • Dull or oily hair
  • Premature wrinkles
  • Split nails
  • Seborrheic dermatitis
  • Dandruff
  • Low Blood Count
  • Lips and corner of mouth chipping
  • Dizziness
  • Hair loss
  • Loss of sleep
  • Poor digestion
  • Slowed mental responses

In healthy individuals vitamin B2 is continuously excreted which means it is important to get the recommended daily dietary intake. Vitamin B2 is also common with other nutrients which also includes most of the B vitamins.

Conditions and diseases linked to Vitamin B2 deficiency

People with Hepatitis, Cirrhosis and Billary obstruction are likely to be deficient in Vitamin B2 as absorption of the vitamin is decreased in these conditions.

Deficiency is also likely, in the elderly, people with eating disorders, chronic alcoholism, HIV, inflammatory bowel disease, diabetes, chronic heart disease and in women taking oral contraceptives. Vitamin B2 deficiency could also lead to malfunctioning of the adrenal glands which have been linked to various conditions such as anemia, chronic fatigue syndrome and cataracts. Vitamin B2 deficiency is also a major cause of preeclampsia in pregnant women. People who smoke are also likely to be deficient in Vitamin B2.

People on a gluten free diet may also be deficient in vitamin B2 due to excluding foods made from wheat that have been enriched with the vitamin such as bread, pasta, cereals. Infants who are being treated with jaundice using Phototherapy may also show signs of deficiency.

Riboflavin is one of the main B vitamins which can cause urine to appear yellow to orange with brightness of color depending on intake of the amount of riboflavin. If your urine is not yellow or the color is too clear you may not be getting enough B-2.

Psyllium reduces absorption of riboflavin from supplements in healthy people. [12]

Boric acid which is a form of boron can reduce the solubility of riboflavin in water. This may reduce the absorption of riboflavin.

People with Methylenetetrahydrofolate Reductase (MTHFR) deficiency taking folic acid may have a deficiency of Riboflavin as Folic acid is likely to lower blood levels of Riboflavin In people with MTHFR.

Toxicity Symptoms of Vitamin B2

Vitamin B2 / Riboflavin toxicity is highly unlikely through diet as you would need to eat large quantities of food containing the vitamin which would be stomach wrenching and impossible. It is possible to get toxicity symptoms through oral supplementation or injections. However it is very rare as the body rapidly excretes the vitamin since it is a water soluble vitamin which the body does not store.

Any vitamins in extremely high doses can be potentially toxic and act as a poison to the entire system and at the very least cause a nutritional imbalance.

When taken in high doses it can cause diarrhea and increase urination.

Side effects have been reported from taking more than 10mg of Riboflavin per day. The side effects include eye damage from sun light, itching, numbing sensations and deep orange urine. It is recommended that people with cataracts shouldn’t take more than 10 mg of Riboflavin per day.

Precautions & warnings for Vitamin B2

It is always important to check with your doctor before taking high doses of vitamin B2 supplements to see if it may interact with any medications causing problems.

Some research has shown that riboflavin is safe when taken at a dose of 15 mg once every 2 weeks for 10 weeks.

Currently many information on warnings are not provided on Riboflavin / Vitamin B2 supplements and its use for migraine sufferers is fairly new. Other nutrients that are agonists for Vitamin B2 should also be maintained as their efficacy are likely to be dependent on sufficient levels.

Birth control pills can deplete the body of various vitamins which includes Riboflavin. Riboflavin can also be decreased if you smoke or drink alcoholic beverages. Taking Riboflavin with certain Tetracycline antibiotics can decrease the effectiveness of these drugs. It is recommended that Riboflavin is taken 2 hours before or 4 hours after taking these types of antibiotics. Certain Tricyclic antidepressants can decrease the amount of riboflavin in the body and likely to be a problem only with large amounts of the medication.

Certain drying medications known as anticholinergic drugs can increase the amount of riboflavin absorbed in the body and caution should be exercised so as not to intake an excessive amount of Riboflavin.

The medication known as probenecid has shown to decrease absorption of riboflavin. []

Phenobarbital might increase the speed at which riboflavin is broken down in the body.