Vitamin B12 deficiency is a widespread, endemic public health problem in India.

Vitamin B12

• It is a water-soluble vitamin that contains cobalt and is therefore scientifically called cobalamin.
• The body can store vitamin B12 for 2 to 5 years, and it can get rid of any excess or unwanted vitamin B12 in the urine.
• The body stores vitamin B12 in the liver. 
• It is a vitamin the body uses to make and support healthy nerve cells. 
• It’s also used to make healthy red blood cells and the genetic material inside cells called DNA. 
• Your body cannot produce B12 on its own, so it must be obtained through foods high in vitamin B12 or supplements. 
• It is naturally found in animal foods such as fish, meat, poultry, eggs, milk, and milk products. 
• It is not present in plant foods unless fortified.

• 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 homocysteine into 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.

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 vegetarian or vegan 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.
• Child Development: Childhood deficiency impairs brain development, attention, and muscle strength.

Key Government Initiatives

• 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.