Vitamin B12 deficiency is widespread in India and often goes undiagnosed despite its effects on long term neurological, cognitive, and physical health. Experts say its subtle symptoms: persistent fatigue, numbness, or poor concentration: are frequently misattributed to stress, ageing or other conditions, delaying diagnosis and treatment. Studies suggest that while this is often viewed purely as a nutritional problem, it goes beyond inadequate intake alone.
Dietary patterns and habits
Experts emphasise that diet remains the primary driver of B12 deficiency in India due to a complex interplay of cultural habits, socio-economic factors, and lifestyle choices.
S. Krishnamoorthy, senior consultant, Kauvery Hospital, Chennai, explains, “B12 is naturally found almost exclusively in animal‑based foods, which makes vegetarians and near-vegetarians particularly vulnerable.” Vijayashree N., chief dietician at MGM Healthcare, Chennai, elaborates, “Limited access to animal-source food can compound the problem”. Even when these foods are available, certain traditional cooking methods such as prolonged heating can reduce the already small amounts of B12 present, leaving many individuals at risk without realising it.
The impact of these dietary patterns is not uniform across the population. Vinitha Krishnan, chief clinical dietician, SIMS Hospital, Chennai, points out that children, young adults, pregnant women, and older adults are particularly susceptible, as their bodies require higher levels of the vitamin to support growth, reproduction, and neurological health.
Vishnu Abishek Raju, medical gastroenterologist at Apollo Hospitals, Chennai notes a paradox: while middle-class vegans may unknowingly avoid fortified foods and face higher deficiency risk, some low-income groups may inadvertently receive trace amounts of B12 from naturally occurring bacterial flora in traditional diets; socio-economic contexts can therefore shape outcomes.
Beyond individual dietary choices, broader socio-cultural practices and urban lifestyle changes influence intake. Nanda Kumar R., senior consultant, general medicine, SRM Global Hospital, Chennai, points out that the increasing reliance on processed foods and plant-based diets pursued for weight management or lifestyle reasons can unintentionally reduce B12 intake, particularly in urban households where professional dietary guidance is limited.
Absorption too, is crucial
Absorption is an equally crucial factor. Dr. Krishnamoorthy explains that conditions such as chronic gastritis, Helicobacter pylori infection, celiac disease and other intestinal disorders can impair B12 uptake. Dr. Krishnan notes ‘functional absorption issues,’ where standard blood tests may show adequate B12 even when the body is not properly utilising it.
Certain medications can exacerbate the problem. Long‑term use of metformin for diabetes and acid‑suppressing drugs can deplete B12 stores over time, Dr. Kumar says. Age‑related reductions in stomach acid, common among older adults, further limit absorption. Dr. Raju adds that structural intestinal defects, tropical sprue and post‑infection gut damage can also be significant contributors to deficiency.
Why is it under diagnosed
Vitamin B12 deficiency often manifests subtly. It usually starts with patients reporting persistent fatigue, weakness, tingling or numbness, poor concentration or mood changes. According to Dr. Krishnamoorthy, neurological symptoms can emerge even in the absence of anaemia, allowing the deficiency to progress undetected. Dr. Krishnan adds that such overlapping symptoms with iron‑deficiency anaemia, thyroid disorders, stress or depression contribute to frequent misdiagnosis in clinical settings.
In the case of children — they may show reduced energy, delayed growth or learning difficulties, while pregnant and lactating women are at increased risk of fatigue and complications affecting foetal development. Dr. Kumar highlights that in older adults, nerve damage and impaired balance can increase fall risk, further threatening independence and quality of life.
Long‑term health consequences
Prolonged B12 deficiency can have serious lasting effects. Dr. Krishnamoorthy warns that untreated cases may lead to irreversible nerve damage, cognitive decline or gait disturbances. In children, insufficient B12 can affect brain development, attention and muscle strength. Ms. Vijayashree notes that deficiencies in pregnant women may contribute to recurrent miscarriages, preterm delivery and low birth weight infants, with potential lifelong implications.
Among older adults, Dr. Krishnan says peripheral neuropathy, memory loss, confusion and increased cardiovascular risk are commonly observed. Dr. Raju adds that severe cases may also present with anaemia‑related cardiac strain, such as shortness of breath and leg swelling.
Public health interventions
Experts highlight that Vitamin B12 deficiency is largely preventable with timely screening, awareness and dietary strategies. They suggest routine testing for high‑risk groups such as children, pregnant and lactating women, strict vegetarians and the elderly, rather than waiting for severe symptoms to manifest. They also stress the need for medically guided supplementation to prevent long‑term complications. Fortification of commonly consumed staple foods such as milk, cereals and flours is viewed as a practical population‑level strategy.
Vitamin B12 deficiency in India reflects a complex interplay of diet, cultural practices, socio‑economic factors and biological vulnerabilities. While its symptoms are often subtle and easily misattributed, early detection and intervention can prevent irreversible neurological damage, improve quality of life, and support healthier growth and development across generations. Experts emphasise a combined approach of awareness, fortification, screening and supplementation to tackle this often overlooked but significant public health issue.
