Revitalising Riboflavin: Unveiling Its Timeless Significance in Human Physiology and Health

Abstract

Since the early twentieth century, research on vitamins has revealed their therapeutic potential beyond their role as essential micronutrients. Riboflavin, known as vitamin B2, stands out for its unique characteristics. Despite numerous studies, riboflavin remains vital, with implications for human health. Abundantly present in various foods, riboflavin acts as a coenzyme in numerous enzymatic reactions crucial for human metabolism. Its role in energy production, erythrocyte synthesis, and vitamin metabolism underscores its importance in maintaining homeostasis. The impact of riboflavin extends to neurological function, skin health, and cardiovascular well-being, with adequate levels linked to reduced risks of various ailments. However, inadequate intake or physiological stress can lead to deficiency, a condition that poses serious health risks, including severe complications. This underscores the importance of maintaining sufficient levels of riboflavin for general wellness. The essential role of riboflavin in immune function further emphasises its significance for human health and vitality. This paper examines the diverse effects of riboflavin on health and stresses the importance of maintaining sufficient levels for overall well-being.

Keywords: coenzyme; human health; metabolic function; riboflavin; therapeutical potential.

Figure 1

Graph: “Number of publications per year collected in the PubMed database for the terms ‘Riboflavin’ and ‘Vitamin B2’ (search conducted on 9 July 2024)”.

Figure 2

The biosynthesis pathway for riboflavin uses one molecule of GTP from the purine biosynthesis route and two molecules of ribulose-5-phosphate from the pentose phosphate pathway to make one riboflavin molecule. This process occurs via a series of processes catalysed by enzymes. There are two separate parts of the process when 3,4-dihydroxy-2-butanone-4-phosphate and 5-amino-6-(5′-phosphoribitylamino) uracil come together. This reaction results in the formation of the riboflavin precursor, 6,7-dimethyl-8-ribityllumazine.

Figure 3

Metabolism and uptake of riboflavin: The gastrointestinal system primarily absorbs riboflavin (RB), with the help of riboflavin transporter 3 (RFVT3). After absorption, gastrointestinal cells can metabolise riboflavin through two pathways. Riboflavin kinase (RFK) can convert it into flavin mononucleotide (FMN), and FAD synthase (FADS) can transform it into flavin adenine dinucleotide (FAD). Alternatively, riboflavin can enter the bloodstream via riboflavin carrier protein-1 (RCP1), transporter 1 (RFVT1), and riboflavin transporter 2 (RFVT2). The circulatory system transports riboflavin to reach its target cells. The maternal circulation transports riboflavin to the foetal bloodstream with the help of RFVT1, expressed in the gastrointestinal system and placenta. RFVT2 is ubiquitously expressed throughout the body and has significant expression in the brain and endocrine organs, including the pancreas. It is also present in the liver and muscle tissue [31]. Riboflavin is used inside the target cells directly or by conversion into either FMN or FAD cofactors for several biological processes. Figure adapted from [32].

Figure 4

Main signs and symptoms of riboflavin deficiency. Figure adapted from [46].