The Role and Significance of Vitamins in Human Physiology

Vitamins are indispensable organic compounds required in small quantities to sustain normal biochemical and physiological functions in humans. Although they do not yield energy themselves, they serve as cofactors, antioxidants, regulators of gene expression, and mediators in diverse metabolic pathways. Deficiencies, excesses (hypervitaminosis), or imbalances in vitamins can provoke a spectrum of pathological states, from subclinical impairment to overt disease. This essay critically examines the classification, biochemical roles, mechanisms of action, deficiency and toxicity consequences, and current challenges in ensuring optimal vitamin status in human populations.