Vitamin B2 is a water-soluble vitamin, it dissolves in water and whatever is not needed passes out of the body in urine.
That is the main reason why consumption of vitamin B2 is needed every day, because the body can only store small amounts, and supplies go down rapidly.
Riboflavin occurs naturally in some foods, added to others, and it can be taken as supplements. Most of it is absorbed in the small intestine. Vitamin B2 helps break down proteins, fats, and carbohydrates. It plays a vital role in maintaining the body’s energy supply.
Function of vitamin B2
Along with vitamin A, vitamin B is essential for:
- Maintaining the mucous membranes in the digestive system
- Maintaining a healthy liver
- Converting tryptophan into niacin, an amino acid
- Keeping the eyes, nerves, muscles and skin healthy
- Absorbing and activating iron, folic acid, and vitamins B1, B3 and B6
- Hormone production by the adrenal glands
- Preventing the development of cataracts
- Fetal development, especially in areas where vitamin deficiency is common (1)
Foods rich in vitamin B2
As all other vitamins there are plenty of sources in our food for B2. Foods that are high in riboflavin B2 are yeast, liver, chicken, eggs, cheese, cilantro and more. Here is a full list of foods high in riboflavin. B2 does also come in supplements, note that for best result B vitamins should be taken together, in a B complex for best result.
“The B-vitamins comprise a group of eight water soluble vitamins that perform essential, closely inter-related roles in cellular functioning, acting as co-enzymes in a vast array of catabolic and anabolic enzymatic reactions.” (2)
Signs of deficiency
Vitamin B2 deficiency is a significant risk when diet is poor, because the human body excretes the vitamin continuously, so it is not stored. A person who has a B2 deficiency normally lacks other vitamins too.
There are two types of riboflavin deficiency:
- Primary riboflavin deficiency happens when the person’s diet is poor in vitamin B2
- Secondary riboflavin deficiency happens for another reason, maybe because the intestines cannot absorb the vitamin properly, or the body cannot use it, or because it is being excreted too rapidly
Riboflavin deficiency is also known as ariboflavinosis.
Signs and symptoms of deficiency include:
A lack of vitamin B2 can lead to mouth ulcers and other complaints.
- Angular cheilitis, or cracks at the corners of the mouth
- Cracked lips
- Dry skin
- Inflammation of the lining of the mouth
- Inflammation of the tongue
- Mouth ulcers
- Red lips
- Sore throat
- Scrotal dermatitis
- Fluid in mucous membranes
- Iron-deficiency anemia
- Eyes may be sensitive to bright light, and they may be itchy, watery, or bloodshot
People who drink excessive amounts of alcohol are at greater risk of vitamin B deficiency. Women taking birth control pills, pregnant or lactating need more B2. Those who eat little or no milk, cheese or meat should consider supplementing B2. All stress calls for more vitamin B2 and other vitamins in the B family.
Signs of excess
Normally, vitamin B2 is considered safe. An overdose is unlikely, as the body can absorb up to around 27 milligrams of riboflavin, and it expels any additional amounts in the urine.
However, it is important to talk to a physician before taking any supplements, especially as these can interfere with other medications.
Supplements can interact with other medications, and B2 supplements may impact the effectiveness of some drugs, such as anticholinergic medications and tetracycline.
Sometimes a doctor may recommend supplementation, for example, if a patient is using a drug that can interfere with the absorption of riboflavin.
Drugs that may interfere with riboflavin levels in the body include:
- Tricyclic antidepressants, such as imipramine, or Tofranil
- Some antipsychotic drugs, such as chlorpromazine, or Thorazine
- Methotrexate, used for cancer and autoimmune diseases, such as rheumatoid arthritis
- Phenytoin, or Dilantin, used to control seizures
- Probenecid, for gout
- Thiazide diuretics, or water pills
Doxorubicin, a drug used in cancer therapy, may deplete levels of riboflavin, and riboflavin may affect how doxorubicin works.
The University of Maryland Medical Center (UMM) note that very high amounts of vitamin B2 may lead to itching, numbness, burning or prickling, yellow or orange urine and sensitivity to light. To prevent an imbalance of B vitamins, they suggest using a B-complex vitamin if supplementation is needed.(3)
Recommended daily dosage
7-10 years 1 mg
men 1,8 mg
women 1,6 mg
pregnant women and lactating 1,8 mg