Abstract
Vitamin D plays an indispensable role in human health, extending beyond skeletal health, influencing cardiovascular, immune, gastrointestinal, and neurocognitive functions. Vitamin D deficiency continues to be a major public health concern despite extensive research on its physiological role and supplementation strategies. Nearly half of the population being deficit or has insufficient vitamin D levels despite strategies such as sun exposure, fortification, and supplementation. Conventional interventions remain insufficient to meet population requirements, especially in limited sun exposure and vegan and vegetarian contexts. This review evaluates the physiological role of vitamin D in skeletal, cardiovascular, immune, gastrointestinal and mental health through clinical and experimental evidence. In addition, this review tries to consolidate the recent advances in nutritional sciences, biotechnology, and nanotechnology for enhancing vitamin D bioavailability and efficacy. Special focus is given to sustainable, non-animalderived sources such as plant and fungal precursors capable of producing vitamin D2/D3 on UVB exposure, and microbial biosynthesis of the vitamin using metabolic engineering. Further, nano-delivery systems are discussed for their ability to improve bioavailability, stability, and solubility of this lipophilic nutrient. All these innovations together may offer scalable and sustainable solutions to address vitamin D deficiency and help support the transition towards plant-based interventions and precise nutrition.
Keywords: Nano-delivery Systems, Plant- and Fungal-derived Vitamin D, Sustainable Vitamin D Production, Vitamin D, Vitamin D Deficiency.