1. Congenital defects (30%):
vitamin-dependent genetic diseases are diseases caused by the lack of specific biochemical reactions catalyzed by certain vitamins. It can only be corrected by giving specific vitamins. For example, the cause of congenital malabsorption of vitamin B12 is the lack of transport globulin after vitamin B12 absorption, and the patient is injected intramuscularly with 1 mg of vitamin B12 twice a week to maintain a normal blood count.
2. Acquired factors (25%):
(1) Physiological factors: During pregnancy and lactation, the human body's demand for various nutrients increases significantly. The basal metabolism in the first 4 months of pregnancy is not much different from that of normal people. Since 5 months, with the gradual increase of basal metabolism, the demand for heat energy has gradually increased. In order to meet the needs of fetal development, the demand for protein, calcium, phosphorus, iron and various vitamins also increases accordingly. For example, fetal iron stores increase from 80 mg to 400 mg in the last 2 months of pregnancy. Within 5 to 6 months after birth, therefore, pregnant women need to provide more iron in the later stages of pregnancy. Insufficient supply of various nutrients during pregnancy will affect the health of pregnant women and the development of the fetus.
(2) Diseases: The following diseases will significantly increase the body's demand for various nutrients: ① Malnutrition absorption caused by sprue syndrome. ② sickle cell hemolytic anemia. ③ tuberculosis and other chronic wasting febrile diseases. ④ Ulcerative colitis and other inflammatory bowel diseases.
(3) Drug-induced malnutrition: Drug-induced malnutrition develops slowly at the onset of the drug. The trend of malnutrition gradually intensified with the prolongation of drug time, leading to vitamin D and folic acid deficiency caused by long-term use of anticonvulsant drugs in epilepsy patients; oral antituberculosis drugs vitamin D and folic acid deficiency; oral antituberculosis drugs can cause folic acid pyridoxine and folic acid deficiency. Niacin deficiency, which is caused by drugs that hinder the absorption or use of vitamins more than other nutrients, followed by other vitamin deficiencies.
(4) Increased demand caused by environmental and professional factors: Humans who are often in special production or living environments, such as those who live or work in high temperature, low temperature, and high altitude environments, can make the body's normal physiological processes, Including nutrients, complex changes occur in metabolic disease examples, so the demand for certain nutrients has also increased significantly. The demand for nutrients has also increased significantly, such as temperature regulation, water, salt metabolism, and the functions of the digestive system and cardiovascular system in high-temperature operators. big change.