BharatNotes What is Vitamins and Deficiency Diseases?
Vitamins are organic compounds needed in tiny amounts for the body to function, yet they cannot be made by the body in sufficient quantity (with limited exceptions like vitamin D from sunlight) and so must come from food. When intake of a particular vitamin falls short over a sustained period, a specific deficiency disease appears. Because the quantities involved are minute, these shortages are often called "hidden hunger" — a person may eat enough calories yet still lack essential micronutrients.
Classification
Vitamins fall into two broad groups based on solubility:
- Fat-soluble vitamins (A, D, E, K) dissolve in fat, are stored in the liver and adipose tissue, and can accumulate to toxic levels if grossly over-supplemented.
- Water-soluble vitamins (B-complex and C) are not stored in any significant amount, are excreted in urine, and therefore need regular dietary intake.
Key Vitamins, Chemical Names and Deficiency Diseases
The table below summarises the major vitamins, their chemical names, principal deficiency disease and common food sources.
| Vitamin | Chemical name | Deficiency disease | Common sources |
|---|---|---|---|
| A | Retinol | Night blindness, xerophthalmia | Carrots, liver, milk, green leafy vegetables |
| B1 | Thiamine | Beriberi | Whole grains, legumes |
| B3 | Niacin | Pellagra (diarrhoea, dermatitis, dementia) | Meat, fish, grains |
| B12 | Cobalamin | Pernicious (megaloblastic) anaemia | Meat, eggs, dairy |
| C | Ascorbic acid | Scurvy (bleeding gums, fatigue) | Citrus fruits, guava, tomato, amla |
| D | Calciferol / Cholecalciferol | Rickets (children), osteomalacia (adults) | Sunlight, fortified milk, fish oils |
| E | Tocopherol | Increased oxidative cell damage | Vegetable oils, nuts, seeds |
| K | Phylloquinone | Impaired clotting, haemorrhage | Green leafy vegetables |
Vitamin B12 is unique in containing the metal cobalt, and its absorption requires "intrinsic factor" secreted by the stomach — failure of this mechanism causes pernicious anaemia.
Significance and Current Status in India
Micronutrient deficiencies remain widespread in India. As per the National Family Health Survey (NFHS-5, 2019-21), 67.1% of children aged 6-59 months, 57% of women aged 15-49 years and 25% of men in the same age group were anaemic — anaemia being driven by iron, folate (vitamin B9) and vitamin B12 shortfalls.
Government interventions include:
- The National Vitamin A Prophylaxis Programme, providing biannual mega-doses to children aged 6-59 months to prevent night blindness.
- Anaemia Mukt Bharat (launched 2018), targeting a 3-percentage-point annual reduction in anaemia across a life-cycle approach.
- Food fortification — by March 2024, fortified rice (enriched with iron, folic acid and vitamin B12) covered government schemes such as TPDS, PM POSHAN and ICDS.
UPSC Angle
For Prelims, lock in the vitamin–chemical-name–disease–source mapping, as questions are usually direct matching items. For Mains, link these deficiencies to "hidden hunger", the malnutrition burden and policy responses (fortification, supplementation, POSHAN Abhiyaan). This is a foundational concept that underpins the broader public-health and food-security question families.
