How Does Riboflavin (Vitamin B2) Function In The Body?

Written by Andy Mobbs
featured image for article on riboflavin vitamin b2, a seneca nootropic ingredient

In today’s article, we will be talking about Riboflavin, aka Vitamin B2, a water-soluble vitamin that is naturally present in many types of foods, including enriched food products. So, why did we add this ingredient to our Seneca Nootropic stack? Does this B vitamin have cognitive-enhancing benefits? Scroll down to find out!

What is Vitamin B2 and what is it good for?

Initially isolated from milk, Riboflavin is also called Vitamin B2 (we’ll be using these terms interchangeably throughout this article). It was the second vitamin discovered, after Thiamine aka Vitamin B1. The B complex vitamins all have important roles to play in cell metabolism, energy production, and red blood cell synthesis (1).

According to the European Food Safety Authority, Riboflavin contributes to the following:

  • Energy-yielding metabolism
  • Nervous system function
  • Normal mucous membranes
  • Normal red blood cells
  • Normal skin
  • Normal vision
  • Iron metabolism
  • Protects cells from oxidative stress
  • Reduces tiredness and fatigue

Additionally, there is also some evidence pointing to Riboflavin’s preventive effects on cataract development, lowering of homocysteine levels, and reduction in frequency of migraine attacks (2, 3).

Vitamin B2 sources: Where can you find Riboflavin?

Food sources of Vitamin B2 include (4):

  • Milk
  • Eggs
  • Oatmeal
  • Yogurt
  • Mushrooms
  • Broccoli
  • Spinach
  • Almonds
  • Organ meat
  • Fortified cereals
  • Fortified grain products

If you can’t get B2 from food, you’ll find it readily available in supplement form. In fact, most brands of multivitamins include the complete lineup of B complex vitamins.

With that being said, another excellent source of Riboflavin in supplement form is our nootropic, Seneca Nootropic Complex. Each serving of Seneca contains 1.3mg of B2 (this is equivalent to 100% of the recommended daily value) in Riboflavin-5-Phosphate form.

Related article: What are nootropics?

Why do we use the form Riboflavin-5-Phosphate in Seneca?

Riboflavin-5-Phosphate aka Flavin Mononucleotide (FMN) is the active form of Vitamin B2, and so is a more bioavailable form than Riboflavin, which is the inactive form. As you’ve learned in the previous section, Riboflavin is an incredibly important vitamin that participates in many biological functions. But for this article, however, we’ll focus on the main Riboflavin-5-Phosphate benefits that made us choose this particular form for Seneca. These are (5):

  • Energy production
  • Antioxidant defense
  • Helps produce the active forms of Folate (B9), Vitamin B6, and Vitamin B3

We’ll cover these benefits more closely in the next section.

How does Riboflavin function in the body?

Here are some of B2’s most important functions that influenced our decision to add B2 (specifically in Riboflavin-5-Phosphate form) to Seneca:

Function #1 – Energy Production

Riboflavin-5-Phosphate or FMN itself is part of Complex 1 in the electron transport chain. The electron transport chain is the most important part of energy production where ATP is finally made in significant amounts. The chain itself is made of 4 major complexes and is a little like a game of ‘hot potatoes’ as electrons are passed down the chain to a place where they can be safely combined with oxygen and antioxidants to produce carbon dioxide and water.

The electron transport chain takes place in the inner membrane of the mitochondria, the powerhouses of our cells. In complex 1, FMN takes an electron from NADH and passes it on to an iron-sulfur cluster, which then passes it on to CoQ10.

Complex 2 of the chain also uses B2 in the form of flavin adenine dinucleotide (or FADH2), another active form of B2. FADH2 is produced in the Krebs or Citric Acid Cycle, which is the preceding part of the energy production cycle to the electron transport chain that also takes place in the mitochondria.

B2 is also one of the cofactors needed for the enzymes pyruvate dehydrogenase complex and α-Ketoglutarate dehydrogenase complex that is also used in the Krebs cycle along with vitamins B1, B3, B5, and lipoic acid (5).

electron transport chain and krebs cycle

Function #2 – Antioxidant Function

Riboflavin is a cofactor for the enzyme glutathione reductase, and glutathione is considered the master antioxidant in the human body (6). However, once it donates its electron to quench free radicals, glutathione itself becomes oxidized. Glutathione reductase catalyzes the reaction which takes an electron from NADPH and gives it to glutathione to reduce it again, so it can continue its function as an antioxidant.

The body needs to keep a ratio of about 90% reduced glutathione (i.e ready to antioxidize, reduction is gaining an electron) to 10% oxidized glutathione (oxidation is losing an electron), so glutathione reductase is hugely important for antioxidant function.

In the example below, glutathione with the enzyme glutathione peroxidase (which also needs selenium) turns hydrogen peroxide into water. Hydrogen peroxide, aka household bleach, is one of the main oxidants found in the human body. It is produced during energy production and is also used by the immune system to kill invaders.

glutathione reductase

However, riboflavin is not just vital for glutathione production. It is also needed to help recycle the antioxidant thioredoxin as a cofactor for the enzyme thioredoxin reductase and for the enzyme NADH peroxidase, which turns hydrogen peroxide and NADH into NAD+ and water. This is in a similar way as glutathione turns hydrogen peroxide into water, but as there is so much hydrogen peroxide used, we need more than one antioxidant that can deal with it.

Function #3 – Active Vitamin Production

Research shows that B2 also helps with active vitamin production, specifically vitamins B3, B6, and B9 Folate (5):

  • B2 is needed for the production of vitamin B3 through a biochemical pathway known as the kynurenine pathway.
  • It’s also needed for the PNPO enzyme that’s involved in turning the inactive form of B6 Pyridoxine into the active form of B6 (P5P).
  • B2 is also needed for the MTHFR enzyme in the Folate cycle that leads to the production of 5 MTHF which is used to turn homocysteine back into methionine.

Riboflavin deficiency symptoms

Riboflavin deficiency is rare in developed countries, but it’s a different story in developing countries, especially in Africa and Asia. Some groups of people have a greater risk of falling deficient to B2, such as vegans, alcoholics, older people, and women who take birth control pills. Deficiency doesn’t happen overnight. After several months of inadequate B2 intake, the following signs of deficiency start showing up (7): 

  • Sores at corner of mouth
  • Lesions and inflammation of lips
  • Inflammation of tongue and oral cavity
  • Anemia
  • Neuropathy
  • Seborrheic dermatitis

What’s the right dosage for Riboflavin?

To avoid experiencing any of the riboflavin deficiency symptoms above, follow these average daily recommended amounts (in mg):

0 to 6 months0.3mg0.3mg
Infants (7-12 months)0.4mg0.4mg
Children (1-3 years)0.5mg0.5mg
Children (4-8 years)0.6mg0.6mg
Children (9-13 years)0.9mg0.9mg
Teenager (14-18 years)1.3mg1.0mg
Pregnant teens and womenn/a1.4mg
Breastfeeding teens and womenn/a1.6mg
Source: National Institutes of Health

Can you overdose on Riboflavin?

Fortunately, the answer is no. There is no upper intake levels for B2. Since this vitamin is water-soluble, any excess B2 you take via food or supplements gets excreted in urine.


In terms of food sources and supplement choices, Riboflavin is a readily available nutrient. With its antioxidant and energy-boosting properties, as well as its contribution to active vitamin production, making sure you meet B2’s recommended daily allowance (see table above) is definitely a must!


(1) “Vitamin B2 (Riboflavin).” Mount Sinai Health System, 2021,

(2) “Riboflavin: MedlinePlus Supplements.” Medline Plus, 2020,

(3) Namazi, Nazli et al. “Supplementation with Riboflavin (Vitamin B2) for Migraine Prophylaxis in Adults and Children: A Review.” International journal for vitamin and nutrition research. Internationale Zeitschrift fur Vitamin- und Ernahrungsforschung. Journal international de vitaminologie et de nutrition vol. 85,1-2 (2015): 79-87. doi:10.1024/0300-9831/a000225

(4) “Office of Dietary Supplements – Riboflavin.” NIH-ODS, 2021,

(5) Saedisomeolia, Ahmad, and Marziyeh Ashoori. “Riboflavin in Human Health: A Review of Current Evidences.” Advances in food and nutrition research vol. 83 (2018): 57-81. doi:10.1016/bs.afnr.2017.11.002

(6) Alfonso Pompella, Athanase Visvikisa, Aldo Paolicchi, Vincenzo De Tata, Alessandro F.Casini, The changing faces of glutathione, a cellular protagonist, Biochemical Pharmacology, Volume 66, Issue 8, 15 October 2003, Pages 1499-1503

(7) Mahabadi N, Bhusal A, Banks SW. Riboflavin Deficiency. [Updated 2020 Jul 21]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: