Harm when excess or deficiency of vitamin B12

The article is professionally consulted by Master, Doctor Nguyen Thi Ngoc - General Internal Medicine - Endocrinology - Department of Examination & Internal Medicine - Vinmec Central Park International General Hospital. Doctor has more than 10 years of studying, researching and working in the field of endocrinology.

Vitamin B12 is necessary for red blood cell production and the development of the nervous system. However, taking too much vitamin B12 can also lead to many serious consequences.

Vitamin B12 is a vitamin belonging to the group of B vitamins, soluble in water and has many important roles in the body as follows:
Participates in the synthesis of DNA, so it plays an important role in the process of replication and reproduction. cells in the body. Plays a role in lipid and folic acid metabolism. Involved in the production of red blood cells Participates in the composition of the myelin sheath of nerves, thereby helping to ensure the normal functioning of the nervous system.

Vitamin B12 is an essential nutrient for the body. Vitamin B12 deficiency usually occurs when there is not enough food or the body has problems absorbing vitamin B12. People with malnutrition, cancer, the elderly, pregnant, alcoholics, etc. are also at high risk of vitamin B12 deficiency. Vitamin B12 deficiency is a fairly common condition and can manifest in neurological and hematological disorders. If the deficiency is severe, it can cause permanent nerve damage:
Vitamin B12 deficiency will lead to neurological disorders such as irritability, hallucinations, changes in natural reflexes, poor muscle function, appearance. memory problems, impaired taste and, in extreme cases, mental disturbances. For children, possible problems include slow growth, poor development, and difficulty with movement. Vitamin B12 deficiency also leads to pernicious anemia. The cause may be a disorder of vitamin B12 absorption due to a lack of intrinsic factor - an element necessary for the absorption of vitamin B12 in the intestine. Vitamin B12 deficiency can cause paresthesia or numbness of the limbs.

Vitamin B12 is water-soluble and excess in the body can be easily eliminated by the kidneys through the urine, so it is less toxic to the body. However, if supplementing with high doses of vitamin B12 for a long time, it will cause side effects for the body:
Anaphylaxis due to an allergy to vitamin B12. This reaction is rare but very dangerous because it can lead to death. Therefore, it is necessary to be cautious when supplementing with vitamin B12, especially in injectable form for people with hypersensitivity. Digestive disorders with manifestations such as loss of appetite, anorexia, nausea, diarrhea... Headache... , rash, itching Causes numbness or weakness in the arms, legs, facial muscles. Causes cardiovascular complications such as increased heart rate, shortness of breath, chest pain, high blood pressure, heart failure,... Increased risk of prostate cancer. Too much vitamin B12 can also activate the blood coagulation system, increase blood clotting, cause blood clots, cause damage to the optic nerve in people with Leber disease - congenital retinal pigment degeneration causing blindness in children.

The need for vitamin B12 with different subjects is as follows:
For adults, the recommended amount of vitamin B12 is 2 mcg/day Pregnant and lactating women are 2.6 mcg/day For children during pregnancy and lactation. Toddlers range from 0.7 mcg/day, and in adolescence up to about 2 mcg/day To provide adequate vitamin B12 for the body, it is necessary to supplement the diet with rich foods. vitamin B12. Vitamin B12 is abundant in beef, salmon, eggs, milk, cheese,... Plant foods do not have vitamin B12. In addition, there are many supplements that contain multivitamins that are high in B12. Supplementing vitamin B12 for the body needs to be very cautious and must absolutely follow the doctor's instructions, when detecting signs of vitamin B12 poisoning, it is necessary to quickly go to the nearest medical facility for emergency and treatment. timely treatment.