1. Epithelial tissue with rapid proliferation is particularly prone to malnutrition, which can cause atrophy, hyperkeratosis and muscular degeneration of pharyngeal epithelial cells, leading to dysphagia;
2. It leads to the disorder of oxidative metabolism of brain cells, leading to excitability and inattention, decreased activity of conducting nerve enzymes, and neuritis and peripheral neuritis;
3. Some patients may have pica;
4. The decrease of iron-containing enzyme activity will lead to the decrease of cellular immune function and easy infection.