It is a water-soluble vitamin that contains cobalt and is therefore scientifically called cobalamin.
It is stored in the liver for about three to fiveyears, allowing the body to use it over time.
Essential Role: It acts as a cofactor in DNA synthesis, the formation of Red Blood Cells (erythropoiesis), and the maintenance of the myelin sheath (the protective covering of nerves).
Metabolic Function: It converts homocysteineinto methionine, regulating amino-acid metabolism.
Absorption: Intestinal absorption requires binding to intrinsic factor (IF), a protein secreted by the parietal cells in the stomach lining.
Sources: It is synthesised by some bacteria and occurs naturally only in animal-derived foods (meat, fish, eggs, dairy); it is not naturally present in plant foods.
About Vitamin B12 Deficiency
Global Prevalence: In developed countries, it mainly affects the elderly, with a prevalence of 6%.
India’s Burden: In India, deficiency affects nearly 47% to 53% of the population across all age groups.
Underdiagnosis:Non-specific symptoms such as fatigue, numbness, or poor concentration, along with prolonged liver storage, delay detection until advanced deficiency.
Major Causes of Deficiency in India
Dietary Habits: The most common cause in India is a vegetarianorvegan diet lacking fortification.
Cooking Patterns: Low milk intake and prolonged boiling reduce the availability of dietary vitamin B12.
Drug Effects: Long-term use of diabetic medications (metformin) and antacids suppresses stomach acid, impairing vitamin B12 absorption.
Major Health Effects
Megaloblastic Anaemia: Impaired DNA synthesis causes RBCs to become abnormally large (megaloblasts) and immature, leading to chronic fatigue.
Demyelination: Inadequate formation of the myelin sheath leads to subacute combined degeneration of the spinal cord, causing neuropathy and gait imbalance.
Psychiatric Disorders: Severe deficiency causes depression, paranoia, and memory loss in the elderly; it can lead to dementia and cognitive decline.
Cardiovascular Risk: Low B12 raises homocysteine, damaging artery linings and increasing early heart attack and stroke risk.
Maternal Complications: Deficiency during pregnancy increases the risk of Neural Tube Defects (NTDs), causing abortions and low birth weight.
Food Fortification: The government mandates supplying fortified rice with iron, folic acid, and B12 through PDS, PM-POSHAN, and ICDS schemes.
Anaemia Mukt Bharat: A “6x6x6” strategy that focuses on six age groups; while traditionally iron-focused, it now emphasises B12 and Folate to tackle “nutritional anaemia” holistically.
Mission Poshan 2.0: A flagship programme aimed at improving maternal and child nutrition through community engagement and behaviour change.
FSSAI Standards: The +F logo on food products helps consumers identify staples like milk or oil fortified with B12 and other micronutrients.
Abhinav Kumar genetics and plant breeding