Health Implications of Vitamin Deficiency

Globally, vitamin deficiencies remain a major public health concern, with nearly two billion people estimated to suffer from micronutrient malnutrition, disproportionately affecting low- and middle-income countries. Vitamin D deficiency is reported worldwide as one billion individuals are estimated either with vitamin D deficient or insufficient and has been related with infectious and non-infectious diseases. Furthermore, an intervention study in 2025 involving over 1,600 adults with low baseline vitamin D levels reported that 50,000 IU vitamin D3 supplementation over two months produced measurable improvements in symptoms and clinical outcomes compared with baseline. Calcitriol is the bioactive form of vitamin D that controls calcium-phosphate homeostasis via interaction with vitamin D receptor (VDR). Vitamin D could have varied roles in conserving health through its regulation of over 200 human genes and the presence of VDR in most cells and tissues.Ultimately, the goal is to inform clinical practice and public health policy on how to identify, prevent, and manage vitamin D deficiency to mitigate its wide-ranging effects.