Vitamin B2

Vitamin B2, also known as riboflavin, is an essential nutrient that plays a crucial role in maintaining overall health and well-being. This water-soluble vitamin is a key component of various metabolic processes, and its deficiency can lead to numerous health issues. 


Vitamin B2 is part of the B-complex family of vitamins, which are essential for energy production, cell growth, and the proper functioning of the nervous system. Riboflavin was first discovered in 1879 by British chemist Alexander Wynter Blyth. However, it was only in 1935 that its chemical structure was identified, and it became widely recognised as an essential vitamin.

Vitamin B2, also known as riboflavin, is an essential micronutrient that plays a critical role in various biochemical processes in the human body. Some of its primary functions include:

  • Energy production: Riboflavin is a component of two essential coenzymes, flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD). These coenzymes are involved in various cellular processes, such as the electron transport chain and the Krebs cycle, which are responsible for energy production in the form of adenosine triphosphate (ATP).
  • Antioxidant activity: Riboflavin plays a role in the body’s antioxidant defence system by contributing to the regeneration of glutathione, one of the most important antioxidants in the body. Glutathione neutralises harmful free radicals, which can cause cellular damage and contribute to aging and various diseases.
  • Metabolism of macronutrients: Vitamin B2 is essential for the metabolism of carbohydrates, fats, and proteins. It helps break down these nutrients into smaller molecules, which can then be used as building blocks for other molecules or as a source of energy.
  • Red blood cell production: Riboflavin is involved in the production of red blood cells, which transport oxygen throughout the body. It also helps maintain healthy levels of homocysteine, an amino acid that, if elevated, can increase the risk of cardiovascular disease.
  • Nervous system function: Vitamin B2 is necessary for the proper functioning of the nervous system, as it supports the synthesis and maintenance of neurotransmitters, such as serotonin and dopamine, which are essential for mood regulation and cognitive function.
  • Vision health: Riboflavin plays a role in maintaining the health of the eyes and preventing eye disorders, such as cataracts. It helps protect the eyes from oxidative stress and supports the function of other important eye nutrients, such as vitamin A.
  • Skin and mucous membrane health: Vitamin B2 contributes to the maintenance of healthy skin and mucous membranes, which form the body’s first line of defence against pathogens.

Good sources Of Vitamin B2

Vitamin B2, or riboflavin, is found in a variety of foods. Good dietary sources of vitamin B2 include:

  • Dairy products: Milk, yogurt, and cheese are rich sources of riboflavin.
  • Eggs
  • Meat and poultry: Lean meats, such as beef, chicken, and turkey, contain significant amounts of riboflavin. Organ meats, like liver and kidneys, are particularly rich in this vitamin.
  • Fish: Fish, especially oily fish like salmon, mackerel, and sardines, are good sources of vitamin B2.
  • Whole grains: Whole grain products like whole wheat bread, brown rice, quinoa, and barley provide riboflavin and other B vitamins.
  • Green leafy vegetables: Vegetables such as spinach, kale, collard greens, and broccoli are good sources of riboflavin
  • Nuts and seeds: Almonds, sunflower seeds, and chia seeds
  • Fortified cereals: Some breakfast cereals are fortified with riboflavin and other B vitamins, providing an easy way to increase your vitamin B2 intake.
  • Nutritional yeast: Nutritional yeast is a popular vegan source of riboflavin and other B vitamins. It has a cheesy, nutty flavour and can be added to a variety of dishes for a nutritional boost.

How Much Vitamin B2 Do We Need?

The recommended dietary allowance (RDA) for vitamin B2 (riboflavin) varies depending on age, sex, and life stage. The National Institutes of Health (NIH) provides the following recommended daily intakes for vitamin B2 (riboflavin):

  • Infants 0-6 months*: 0.3 mg/day (milligram)
  • Infants 7-12 months*: 0.4 mg/day
  • Children 1-3 years: 0.5 mg/day
  • Children 4-8 years: 0.6 mg/day
  • Children 9-13 years: 0.9 mg/day
  • Teens 14-18 years (males): 1.3 mg/day
  • Teens 14-18 years (females): 1.0 mg/day
  • Adults 19 years and older (males): 1.3 mg/day 
  • Adults 199 years and older (females): 1.1 mg/day
  • Pregnant women: 1.4 mg/day
  • Breastfeeding women: 1.6 mg/day

* Adequate intake (AI)

Please note that these values are for general informational purposes and may not be suitable for everyone. Always consult with a healthcare professional for personalised recommendations based on your individual needs and circumstances.

What Are The Signs of Vitamin B2 Deficiency?

Severe vitamin B2 deficiency is rare but can lead to a condition called ariboflavinosis. Some of the signs and symptoms of vitamin B2 deficiency include:

  • Fatigue and weakness: A lack of vitamin B2 can lead to feelings of fatigue, weakness, and general malaise, as it is crucial for energy production in the body.
  • Cracked and sore lips: Vitamin B2 deficiency can cause angular cheilitis, which is characterised by painful cracks and sores at the corners of the mouth.
  • Swollen, red tongue: Vitamin B2 is important for maintaining a healthy mouth, and deficiency can lead to a condition called glossitis, causing the tongue to become swollen, red, and painful.
  • Skin issues: A deficiency in vitamin B2 can result in seborrheic dermatitis, which presents as oily, scaly skin, particularly around the nose, eyebrows, and ears.
  • Sensitivity to light: Inadequate vitamin B2 levels can cause the eyes to become sensitive to light, leading to burning, itching, and tearing.
  • Anaemia: Vitamin B2 is necessary for the proper formation of red blood cells, and deficiency can contribute to anaemia, causing additional symptoms such as pale skin, dizziness, and shortness of breath.
  • Nerve dysfunction: Vitamin B2 deficiency can affect the nervous system, leading to symptoms like numbness, tingling, and burning sensations in the hands and feet.
  • Weakened immune system: A lack of vitamin B2 can impair immune function, making individuals more susceptible to infections and illnesses.
  • Slow wound healing: Vitamin B2 is essential for proper cellular growth and repair, and deficiency can lead to slow or impaired recovery from injuries.

What Happens If I Take Too Much Vitamin B2?

Vitamin B2, or riboflavin, is a water-soluble vitamin, which means that any excess intake is typically excreted through urine rather than stored in the body. As a result, the risk of toxicity from consuming too much vitamin B2 is relatively low.

However, extremely high doses of riboflavin from supplements can cause some side effects, although they are generally mild and reversible. Some potential side effects of excessive vitamin B2 intake include:

  • Yellow-orange discoloration of urine: High doses of riboflavin can cause your urine to turn a bright yellow-orange colour. This is usually harmless and goes away once you reduce your intake of the vitamin.
  • Diarrhoea: Consuming excessive amounts of riboflavin may lead to diarrhoea in some individuals.
  • Stomach discomfort: High doses of vitamin B2 can cause stomach discomfort or pain in some people.
  • Sensitivity to light: In rare cases, excessive riboflavin intake may lead to increased sensitivity to light, causing eye discomfort or pain when exposed to bright light.

It’s essential to remember that these side effects are generally associated with very high doses of riboflavin, which are usually obtained from supplements rather than food sources. Consuming a balanced diet rich in a variety of foods that provide vitamin B2 is the best way to meet your nutritional needs without risking adverse effects. If you are considering taking vitamin B2 supplements or have concerns about your riboflavin intake, consult with a healthcare professional or registered dietitian for personalised advice.