Importance of Nutrient Requirements of Humans

Optimal nutrition is crucial for human health and well-being. Hence, understanding the nutrient requirements of humans is important for researchers, healthcare givers, and policymakers to tackle the problem of nutritional deficiencies and associated health issues. In general, the human body has the ability to adjust to natural fluctuations in dietary intakes by regulating the absorption and excretion of nutrients, in a process called homeostasis that help optimize the utilization of nutrients. Under healthy conditions or balance, the amount of nutrient absorbed is equal to that of its excretion. Therefore, nutrient requirements are factorially computed by summing the losses through all possible routes along with its associated variation in healthy population (specific age and physiological groups), resulting in a distribution of physiological requirements. These are adjusted for absorption/bioavailability to derive the dietary requirement distribution. The mean of this distribution is estimated average requirement (EAR) and the upper 97.5th centile is referred to as recommended dietary allowance (RDA). These metrics are applied in measuring dietary inadequacies, developing dietary guidelines and diet plans, and regulating the food industry. The goal is to achieve nutrient intakes above the EAR (for population) or RDA (for individuals) to reduce the risk of deficiencies. Nutrient requirements are important in food fortification including crop biofortification as they help in setting the target nutrient levels in foods. In this chapter an attempt was made to simplify various aspects related to nutrient homeostasis, requirements, and their applications particularly in the context of fortification.