食盐自古以来是人们沿用的佐餐调料,它的主要成分是氯化钠。十九世纪发现钠元素及钠在体内的代谢和生理功能后,认识到食盐不仅是一种调料而且还能供给人体必需的营养素。早期对氯化钠需要量的研究,着重于高温作业如何防止缺盐的问题。自五十年代开始发现食盐与高血压的关系以来,限制膳食食盐和补充钾盐等,又成为研究的中心课题。迄今为止,对不同劳动条件下适宜的食盐需要量还在研究中。一、钠的代谢钠是细胞外液中主要的阳离子,它的主要生理功能是维持人体渗透压和体液平衡。钠离子和氯离子、碳酸氢根结合又有维持酸、碱平衡的作用。钠在维持肌肉收缩和神经传导的应激性中也是一个主要的因素。人体钠的测定方法有化学分析法、同位素稀释法、中子活化法。成人总体 Salt since ancient times, people continue to use spices, its main ingredient is sodium chloride. The 19th century found that sodium and sodium in the body after the metabolic and physiological functions, recognized that salt is not only a seasoning but also provide the necessary nutrients for the body. Early study of the need for sodium chloride, focusing on how to prevent the problem of lack of salt at high temperature. Since the 1950s, when the relationship between salt and hypertension has been found, the restriction of dietary salt and potassium supplement has become the central issue of research. To date, suitable salt requirements under different working conditions are still under study. First, the sodium metabolism Sodium is the main cation in the extracellular fluid, its main physiological function is to maintain the body’s osmotic pressure and body fluid balance. Sodium ions and chloride ions, bicarbonate has the role of acid and alkali balance. Sodium is also a major factor in maintaining muscle contraction and nerve conduction stress. Human sodium determination of chemical analysis, isotope dilution method, neutron activation method. Adults overall