Hidden hunger, also known as micronutrient deficiencies, remains an important global public health issue despite improvements in overall food security. Among essential micronutrients, vitamin D and zinc have important roles in immune regulation, skeletal development, and metabolic functions. But deficiencies in these nutrients are prevalent particularly among vulnerable groups such as children, pregnant women, and the elderly. This review examines the physiological functions, deficiency epidemiology, health consequences, dietary sources, and the necessity of food fortification with vitamin D and zinc. Furthermore, it discusses the synergistic effects of vitamin D and zinc, and technological methods and challenges for fortifing foods with both vitamin D and zinc. Future research should focus on developing new encapsulation technologies, optimizing nutrient delivery systems, and undertaking long-term clinical trials to validate the health benefits of new co-fortified foods.