Introduction of Vitamin-B12
Table of Contents
Vitamin B12 is naturally present in animal foods like fish, meat, poultry, egg, milk, and other dairy product. It is also available in foods or supplements. It requires the formation of red blood cells (RBCs) and DNA which play a key role in the function and development of brain and nerve cells. Vitamin B12 binds to the protein in the foods we are eating. It is essential for protein and DNA synthesis to keep our body’s nerves, brain, and blood cells healthy and to prevent megaloblastic anemia.
Vitamin-B12 Level- Test Result, Unit, Normal Range, Test Method, and Clinical Significance

Keynotes on Vitamin-B12
- Vitamin B12 is also called cobalamin.
- Sources of Vitamin B12 are food sources, liver, fish, shellfish, egg, red meat, poultry, dairy products such as milk, cheese, and yogurt, fortified nutritional yeast, fortified breakfast cereals, and enriched soy or rice milk.
- Signs of Vitamin-B12 deficiency may include anemia (Megaloblastic and Pernicious), fatigue, weakness, nerve damage with numbness, and tingling in the hands and legs, memory loss, confusion, dementia, depression, and even seizures.
- Factors that may cause vitamin B12 deficiency are avoiding animal products, lack of intrinsic factor, inadequate stomach acid or medications that cause decreased stomach acid, and intestinal surgeries or digestive disorders that cause malabsorption.
- The recommended dietary intake of this vitamin is as follows-
S. No | Age group | Daily-Dose (micrograms (mcg) |
1. | 14 years and older men/women | 2.4 |
2. | Pregnancy | 2.6 |
3. | Lactation | 2.8 |
- It is estimated that up to 15% of the general population is suffering from vitamin B12 deficiency.
- There is no major invasive medical procedure required for this assay. Only the blood is drawn for this test.
- This test is essential in clinical conditions like anemia (Megaloblastic and Pernicious), fatigue, weakness, nerve damage with numbness, and tingling in the hands and legs, memory loss, confusion, dementia, depression, and even seizures.