Salt is generally not allowed for 9-month-olds and is recommended for ages one year and older. Although 9-month-old babies can eat some complementary foods, salt is generally not recommended. Because 9-month-old babies’ kidneys are not yet fully developed and their kidney function is in an imperfect condition. Eating salt in this case will increase the burden on the kidneys and aggravate the functional load of the kidneys. It may lead to swelling of the baby’s eyes, indigestion, and even affect development and calcium deficiency. Generally, babies over one year old can add a small amount of salt inside the complementary food. Because the development of kidney function of one-year-old babies is close to that of adults, eating a moderate amount of salt usually will not affect the body. Appropriate addition of some edible salt, but also conducive to the baby to maintain the balance of water and salt metabolism. Therefore, in order to avoid the impact on the growth and development of the baby, 9 months baby is not recommended to eat salt.