Vitamin B2 (Riboflavin USP)

What is Riboflavin?

Vitamin B2, or Riboflavin, is an essential water-soluble vitamin that plays a key role in energy maintenance, production, and metabolic function (5,6,7). It’s naturally present in various foods, added to fortified products like bread, milk, and cereals (2,6), and available in supplement form. Unlike fat-soluble vitamins that can be stored long-term, riboflavin is water-soluble, meaning our bodies don’t retain large amounts, and we must consume it daily.

Riboflavin plays an essential role in activating or converting other nutrients – particularly iron and B6 (11) – into bioactive forms that can be used by the body (1). It’s also the vitamin that causes your urine to turn bright, bright yellow.

Why Do Outdoor Adventurers Need Riboflavin?

Riboflavin is a powerhouse when it comes to the maintenance of energy (7). It helps convert carbohydrates, fats, and proteins into ATP (energy), which is crucial for endurance and stamina on the trail (1). It also plays a role in red blood cell production and antioxidant activity, helping to reduce oxidative stress caused by intense physical exertion – although more human research is needed in this area (9).

Since hikers and endurance athletes generate more free radicals through high-energy output, riboflavin’s antioxidant properties become even more important for muscle recovery and reducing fatigue (8). We know that inadequate riboflavin intake can lead to reduced aerobic capacity and energy metabolism efficiency, which is bad news when tackling steep inclines (10).

Additionally, riboflavin is essential for iron metabolism, ensuring oxygen is efficiently transported through the bloodstream (11). Without enough B2, physical performance and energy levels will drop. 

B2 is also showing promise as a means of reducing the frequency of migraine headaches (6), although research is ongoing and currently quite balanced in terms of both proving and disproving this effect (11,15). The Canadian Headache Society (yes, this is a real organisation!), has ruled that it ‘probably’ is beneficial for migraine sufferers, but dosages need to be in excess of 400mg according to research so far (12,15). 

Dietary Sources of Riboflavin?

Riboflavin is found in a variety of foods, including eggs, dairy, lean meats, green vegetables, and whole grains but most Australians get their quote from fortified milk (2). It is also added to cereals and bread to help the average person meet their daily intake requirements (1). 

While obtaining riboflavin off-trail is pretty easy, finding high-riboflavin foods that are lightweight and shelf-stable for hiking can be a challenge.

What’s the Best Form of Riboflavin For Hikers?

Riboflavin exists in multiple forms, including riboflavin-5’-phosphate (the active coenzyme form) and synthetic riboflavin, which is the most commonly used in fortified foods and supplements (11).

The synthetic form of riboflavin is widely used in supplements due to its stability, and proven bioavailability. When consumed, the body converts it into its active forms (flavin mononucleotide and flavin adenine dinucleotide), which are immediately available for metabolic functions (11,13).

The coenzyme form, riboflavin-5’-phosphate, is already activated and theoretically more readily available for use in the body. However, research suggests that regular riboflavin is still highly bioavailable, making both forms effective (11).

Because excess riboflavin is excreted in urine (hello, neon yellow pee!), toxicity is virtually unheard of, even at very high doses (6).

Key Information About Riboflavin

Deficiency Stats

While riboflavin deficiency is rare in developed countries due to fortified foods, it can still occur, particularly in individuals with high energy demands (like hikers), those on restrictive diets, or people with malabsorption conditions.

According to data from the Australian Bureau of Statistics data, 8% of males and 19% of females have inadequate riboflavin intake (2). In the US, approximately 6% of adults fall short (3). Early signs of deficiency include fatigue, cracked lips, sore throat, and light sensitivity (3).

Why Optiventure Has 3mg of Vitamin B2 – Riboflavin USP

The optimal intake of riboflavin remains uncertain, with the RDI set at 1.3mg for adult men and 1.1mg for women (3,4). However, research suggests that individuals engaged in endurance sports may benefit from a higher intake due to increased metabolic turnover and oxidative stress (10).

Since excess riboflavin is excreted rather than stored, there’s minimal risk of overconsumption. Studies show that the body absorbs little riboflavin from a single dose above 27mg (3), and many studies on migraines are using dosages of 400mg or more without adverse effects (10, 11,15).

While riboflavin-5-phosphate has slightly superior bioavailability to Riboflavin, at a small dosage of 3g, the difference is indistinguishable between the two, and you’ll find both forms used in commonly available supplements (14). The USP in the form of Riboflavin we chose for Optiventure refers to ‘United States Pharmacopeia’ and means it meets the standards of quality, purity, strength, and consistency set by the nonprofit regulatory organisation.

By including 3mg of riboflavin in Optiventure, we ensure hikers and adventurers receive 231% (men) and 273% (women) of their daily intake, supporting sustained energy and recovery without unnecessary excess.

References

1. National Health and Medical Research Council & New Zealand Ministry of Health. (2006). Nutrient reference values for Australia and New Zealand. Retrieved fromhttp://www.nrv.gov.au/nutrients/riboflavin
2. Australian Bureau of Statistics. (2015). Australian health survey: Usual nutrient intakes, 2011-12. Retrieved fromhttps://www.abs.gov.au/statistics/health/health-conditions-and-risks/australian-health-survey-usual-nutrient-intakes
3. National Institutes of Health. (n.d.). Riboflavin: Fact sheet for health professionals. Office of Dietary Supplements. Retrieved March 5, 2025, fromhttps://ods.od.nih.gov/factsheets/Riboflavin-HealthProfessional/
4. National Health and Medical Research Council. (2006). Nutrient reference values for Australia and New Zealand, including recommended dietary intakes: Riboflavin. Retrieved fromhttps://www.eatforhealth.gov.au/nutrient-reference-values/nutrients/riboflavin
5. Cardoso, D. R., Libardi, S. H., & Skibsted, L. H. (2012). Riboflavin as a photosensitizer: Effects on human health and food quality. Food & Function, 3, 487–502.
6. Buehler, B. A. (2011). Vitamin B2: Riboflavin. Journal of Evidence-Based Complementary & Alternative Medicine, 16(2), 88–90.https://doi.org/10.1177/1533210110392943
7. Da Silva-Araújo, E. R., Toscano, A. E., Silva, P. B. P., dos Santos Junior, J. P., Gouveia, H. J. C. B., da Silva, M. M., Souza, V. S., de Freitas Silva, S. R., & Manhães-de-Castro, R. (2025). Effects of deficiency or supplementation of riboflavin on energy metabolism: A systematic review with preclinical studies. Nutrition Reviews, 83(2), e332–e342.https://doi.org/10.1093/nutrit/nuae041
8. Hoffman, M. D., Valentino, T. R., Stuempfle, K. J., & Hassid, B. V. (2017). A placebo-controlled trial of riboflavin for enhancement of ultramarathon recovery. Sports Medicine - Open, 3(1), Article 8.https://doi.org/10.1186/s40798-017-0081-4
9. Olfat, N., Ashoori, M., & Saedisomeolia, A. (2022). Riboflavin is an antioxidant: A review update. British Journal of Nutrition, 128(10), 1887-1895. https://doi.org/10.1017/S0007114521005031
10. Pinto, J. T., Zempleni, J., & Rucker, R. B. (2020). The role of riboflavin in nutrition and human health. International Journal of Molecular Sciences, 21(11), 3847.https://doi.org/10.3390/ijms21113847
11. Linus Pauling Institute. (n.d.). Riboflavin. Oregon State University. Retrieved March 5, 2025, fromhttps://lpi.oregonstate.edu/mic/vitamins/riboflavin
12. Pringsheim, T., Davenport, W., Mackie, G., Worthington, I., Aubé, M., Christie, S. N., et al. (2012). Canadian Headache Society guideline for migraine prophylaxis. Canadian Journal of Neurological Sciences, 39(S1), S1-59.
13. National Institutes of Health. (n.d.). Riboflavin: Fact sheet for health professionals. Office of Dietary Supplements. Retrieved March 5, 2025, fromhttps://ods.od.nih.gov/factsheets/Riboflavin-HealthProfessional/
14. Hendler, S., & Rorvik, D. (Eds.). (2001). PDR for nutritional supplements. Medical Economics Company, Inc.
15. Chen, Y. S., Lee, H. F., Tsai, C. H., Hsu, Y. Y., Fang, C. J., Chen, C. J., Hung, Y. H., & Hu, F. W. (2022). Effect of vitamin B2 supplementation on migraine prophylaxis: A systematic review and meta-analysis. Nutritional Neuroscience, 25(9), 1801-1812. https://doi.org/10.1080/1028415X.2021.1904542
16. Hanna, M., Jaqua, E., Nguyen, V., & Clay, J. (2022). B vitamins: Functions and uses in medicine. The Permanente Journal, 26(2), 89. https://doi.org/10.7812/TPP/21.204