All About Vitamin B2 RDA and Deficiency

vitamin B2 RDA

Vitamin B2, also known as riboflavin, is one of the eight B-complex vitamins. It is an essential nutrient that helps to build red blood cells, boosts energy levels and supports other cellular functions in the body. In fact, vitamin B2 is critical to the proper development of many things in the body, such as the lining of the digestive tract and the skin.

Maintaining the right levels of riboflavin in your body has many benefits for your overall health. It helps to prevent vitamin B2 deficiency as well as other associated nutritional deficiencies. For example, because riboflavin is involved with processing nutrients, riboflavin deficiency can lead to iron deficiency and anaemia. Learn all about vitamin B2 RDA below.


What Is the Recommended Daily Allowance for Vitamin B2?

Because it’s a water-soluble nutrient, vitamin B2 is flushed out of the body daily, which means it must be restored every day.

For adults, the vitamin B2 RDA is:

  • 3mg for adult men
  • 1mg for adult women


The Recommended Daily Allowance (RDA) of riboflavin depends on age, gender and reproductive status. Not everyone’s vitamin B2 RDA is the same and certain health conditions might require slightly larger doses of riboflavin to support healthy body functions.

  • For pregnant women, the riboflavin RDA is 1.4mg per day.
  • For lactating women, the vitamin B2 RDA is 1.6mg per day.
  • For addressing vitamin B2 deficiency, the RDA ranges between 5 and 30mg per day.
  • For treating cataracts, a combination of 3mg riboflavin and 40mg niacin daily is recommended.
  • For addressing migraine headaches, a daily dose of 400mg riboflavin for at least three months has been shown to relieve symptoms.
  • For high levels of homocysteine in the blood, the riboflavin RDA is 1.6mg per day for 12 weeks.


Children have different riboflavin intake requirements depending on age:

  • Infants up to 6 months old: 0.3mg per day
  • Infants 7-12 months old: 0.4mg per day
  • Children 1-3 years old: 0.5mg per day
  • Children 4-8 years old: 0.6mg per day
  • Children 9-13 years old: 0.9mg per day
  • Teenagers 14-18 years old: 1.3mg per day for males and 1.0mg per day for females

In cases of vitamin B2 deficiency in children, a one-time dose of 2mg followed by a daily dose of 0.5 – 1.5mg for 14 days is recommended. Alternatively, a daily dose of 5mg five days per week for up to one year might help to address riboflavin deficiency in children.


Vitamin B2 (Riboflavin) Deficiency

There are two types of riboflavin deficiency: primary and secondary. While primary riboflavin deficiency results from insufficient vitamin B2 intake, secondary riboflavin deficiency is caused by various health conditions. These include:

  • Chronic diarrhoea
  • Conditions with malabsorption, such as gluten intolerance and inflammatory bowel syndrome (IBS)
  • Chronic liver disease
  • Hemo- and peritoneal dialysis
  • Alcoholism
  • Long-term use of barbiturates


Secondary riboflavin deficiency generally appears when the body can’t absorb vitamin B2 properly, or when it can’t use it once absorbed. It can also appear if it’s excreted too rapidly.

Riboflavin deficiency is also known as ariboflavinosis. Most people with vitamin B2 deficiency are also deficient in other B vitamins. For example, you’re more likely to have vitamin B6 deficiency if you’re also riboflavin deficient.


Signs and Symptoms of Riboflavin Deficiency

Vitamin B2 deficiency can cause a wide range of symptoms, which include:

  • Stomatitis of the mouth and tongue
  • Cheilosis (chapped and/or fissured lips)
  • Visual disturbances (including night blindness)
  • Mild anaemia
  • Migraine headaches
  • Scrotal dermatitis
  • Depression
  • Itchy, watery or bloodshot eyes


Overdose and Toxicity

Vitamin B2 is generally considered safe. There is no daily Upper Intake Level (UL) for vitamin B2, which is the highest intake amount that isn’t likely to cause adverse effects. The risk of riboflavin overdose is unlikely as the body can absorb up to 27mg of vitamin B2 and it eliminates the rest through urine.

Most people will be able to take enough riboflavin from their diet. However, if you’re either vitamin B2 deficient or would like to increase your daily intake, you can choose to take riboflavin supplements. These are available in doses of 25mg to 100mg.

Sometimes, taking a vitamin B2 supplement only can result in an imbalance of B-complex vitamins in the body. To avoid this, it’s recommended to take a B-complex vitamin supplement instead.