GS-III · Science & Technology · Biology · Nutrition
Nutrients — Carbohydrates, Proteins, Fats, Vitamins & Minerals 🥗
Complete UPSC Notes — Five essential nutrient groups, their functions, sources, deficiency diseases, and India's nutrition crisis. Covers macronutrients (carbs, proteins, fats), micronutrients (vitamins A–D, B-complex, minerals — iron, calcium, iodine), deficiency diseases, glycemic index, cholesterol, and current affairs (GHI 2024, NFHS-5, POSHAN 2.0, fortified rice, Lancet micronutrient study, Anemia Mukt Bharat).
🟠 Carbs: primary energy source | 4 kcal/g | glucose → glycogen → fat
🔵 Protein: 20 amino acids | 9 essential | 4 kcal/g | builds muscle, enzymes, antibodies
🟣 Fats: 9 kcal/g | fat-soluble vitamins (A,D,E,K) | LDL (bad) vs HDL (good)
🟢 Vitamins: fat-soluble (A,D,E,K) vs water-soluble (B-complex, C)
🔴 India GHI 2024: 105th/127 countries | 35.5% stunted | 18.7% wasted (world's highest)
📚 Legacy IAS — Civil Services Coaching, Bangalore · Updated: April 2026 · All Facts Verified
Section 01 — Foundation
🍽️ What Are Nutrients — The Big Picture
💡 Think of Your Body as a Factory
Carbohydrates = fuel/electricity for the factory (primary energy). Proteins = workers and machinery (build and repair everything). Fats = insulation, lubricants, and long-term fuel reserve. Vitamins = oil for the machines (tiny amounts, huge effects — without them, machines break down). Minerals = nuts, bolts, and structural steel (calcium for bones, iron for blood, iodine for thyroid). Water = the factory's transport system. Remove any one of these and the factory breaks down — each has unique, irreplaceable functions.
📌 Two Categories: Macronutrients — needed in large amounts, provide energy: Carbohydrates (4 kcal/g), Proteins (4 kcal/g), Fats (9 kcal/g). Micronutrients — needed in tiny amounts but critical: Vitamins and Minerals. Neither provide energy but their absence causes severe diseases. Water is indispensable but not classified as a nutrient.
🍚
Carbohydrates
Primary fuel | 4 kcal/g | Glucose → Glycogen
🥩
Proteins
Build & repair | 4 kcal/g | 9 essential AAs
🫒
Fats / Lipids
Energy store | 9 kcal/g | Vitamins A,D,E,K
🍊
Vitamins
No energy | Regulate metabolism | 13 types
🦴
Minerals
No energy | Structural + regulatory | 20+ types
🔄 How Nutrients Flow Through the Body
🍽️
FOOD
Carbs · Protein
Fats · Vitamins
🦠
GUT / SI
Absorption
into bloodstream
🫁
LIVER
→ Glucose synthesis
→ Glycogen store
→ Lipid processing
⚡
ENERGY (ATP)
Immediate use
🫗
FAT STORE
Surplus → adipose
⏩ Fasting:
Glycogen reserves broken down → Glucose released → Energy. Liver glycogen (~100g) lasts ~12–18 hrs.
⚠️ Prolonged fast:
Glycogen depleted → Fat burned (ketosis). If fat also depleted → Protein catabolism → Kidney strain + harmful byproducts.
Section 02 — Macronutrient 1
🍚 Carbohydrates — The Body's Preferred Fuel
📌 Definition: Carbohydrates (carbs) are organic compounds made of Carbon (C), Hydrogen (H), and Oxygen (O) in a 1:2:1 ratio — general formula (CH₂O)n. They are the body's primary and preferred energy source, especially for the brain and red blood cells. Energy yield: 4 kcal per gram.
🟠 Simple Carbohydrates (Sugars)
Monosaccharides (single sugar units): Glucose (blood sugar, primary cellular fuel), Fructose (fruit sugar), Galactose (milk sugar). Directly absorbed — no digestion needed.
Disaccharides (two sugar units): Sucrose (table sugar = glucose + fructose), Lactose (milk sugar = glucose + galactose), Maltose (malt sugar = glucose + glucose).
Characteristics: Rapidly digested and absorbed → causes quick blood sugar spike → high glycemic index. Found in: fruits, dairy, table sugar, candy, soft drinks, syrups, honey.
UPSC TRAP: Fructose is a simple sugar but has a low glycemic index (metabolised in liver, not directly absorbed into blood) — despite being "simple." Lactose intolerance = lack of enzyme lactase to break down lactose.
🟢 Complex Carbohydrates
Oligosaccharides (3–10 units): Raffinose, Stachyose (in beans — cause gas because humans lack enzyme to digest them; gut bacteria ferment them).
Polysaccharides (many units):
• Starch (plant storage carb): amylose + amylopectin. Found in rice, wheat, potatoes, corn, legumes.
• Glycogen (animal storage carb): highly branched; stored in liver (100–120g) and muscles (~250–400g). Broken down to glucose during fasting.
• Cellulose (dietary fibre): humans cannot digest it → forms bulk, aids bowel movement, reduces cholesterol absorption.
Characteristics: Slow digestion → gradual blood sugar rise → low glycemic index → preferred for diabetes/hypertension patients. Found in: whole grains, legumes, potatoes, beets, cereals.
📌 Glycemic Index (GI) — UPSC Important: A measure of how quickly a food raises blood sugar. Low GI (<55): oats, lentils, beans, brown rice — slow release, preferred for diabetes, PCOS, heart disease. High GI (>70): white bread, white rice, glucose, corn flakes — rapid blood sugar spike. The WHO and ICMR recommend low-GI diets to prevent and manage Type 2 diabetes, which affects over 101 million Indians (IDF 2023).
⚡ Functions of Carbs
- Primary energy: 4 kcal/g; brain uses ~120g glucose/day exclusively
- Protein-sparing: when carbs adequate, protein used for building (not energy)
- Glycogen storage: liver + muscles = ~400–500g total
- Dietary fibre: prevents constipation, lowers cholesterol, feeds gut bacteria
- Part of nucleic acids: ribose (RNA) and deoxyribose (DNA) are 5-carbon sugars
- Cell recognition: glycoproteins on cell surfaces
🏥 Carb Metabolism — Key Points
- Digestion starts in mouth (salivary amylase)
- Main absorption in small intestine
- All sugars converted to glucose in liver
- Surplus → glycogen (liver, muscle) → then fat
- Insulin: allows cells to absorb glucose; deficiency = diabetes
- During fasting: glucagon breaks glycogen → glucose
- If glycogen depleted: body burns fat → ketosis
- If fat also depleted: protein catabolism → kidney strain
⚠️ Disorders & Issues
- Diabetes mellitus: Type 1 (no insulin) or Type 2 (insulin resistance) — high blood glucose
- Hypoglycaemia: low blood glucose — dizziness, fainting
- Kwashiorkor: protein-energy malnutrition when carbs available but protein deficient
- Obesity: excess carb → fat storage
- Lactose intolerance: lactase deficiency — bloating, diarrhoea
- Celiac disease: gluten (in wheat) triggers immune response → gut damage
Section 03 — Macronutrient 2
🥩 Proteins — The Body's Workers
📌 Definition: Proteins are large biological molecules made of chains of amino acids. There are 20 amino acids used by the human body. 9 are essential (cannot be synthesised by body — must come from food): Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, Valine. Mnemonic: HILL MTV P (Histidine, Isoleucine, Leucine, Lysine, Methionine, Threonine, Valine, Phenylalanine). Energy: 4 kcal/g. Proteins are the most versatile molecules in the body.
🔵 Functions of Proteins
- Structural: collagen (skin, tendons, bones), keratin (hair, nails), actin/myosin (muscle)
- Enzymatic: ALL enzymes are proteins (amylase, pepsin, DNA polymerase)
- Hormonal: insulin, glucagon, growth hormone, FSH, LH are protein hormones
- Transport: haemoglobin (carries O₂), albumin (transports drugs, fatty acids in blood)
- Immune: antibodies (immunoglobulins) are proteins — fight infections
- Energy: last resort when carbs/fats depleted (4 kcal/g)
- Fluid balance: plasma proteins maintain osmotic pressure — prevents oedema
- Clotting: fibrinogen, thrombin — blood coagulation proteins
🥚 Sources & Quality
Complete proteins (contain all 9 essential AAs): Meat, fish, eggs, dairy, soy (only complete plant protein). Animal proteins have higher biological value.
Incomplete proteins (missing 1+ essential AAs): Most plant proteins — legumes, cereals, nuts, seeds. Can be combined to complement each other (rice + lentils = complete protein — the principle behind India's dal-chawal!).
Key facts:
• Breast milk: perfectly balanced amino acid profile for infants
• Soya bean: highest quality plant protein (~36% protein content)
• Egg protein (albumin): reference standard (biological value = 100)
• Protein deficiency → Kwashiorkor (children) — oedema, bloated belly, hair changes, skin lesions
• Severe energy-protein deficiency → Marasmus — severe wasting, muscle loss
Section 04 — Macronutrient 3
🫒 Fats / Lipids — Energy Reserve & More
📌 Definition: Lipids are organic compounds insoluble in water but soluble in organic solvents. Include fats (solid at room temperature), oils (liquid), waxes, phospholipids, and sterols (cholesterol). Highest energy density: 9 kcal per gram — more than twice the energy of carbs or proteins. Essential for fat-soluble vitamin absorption (A, D, E, K).
🟣 Saturated vs Unsaturated Fats
Saturated fatty acids (SFAs): No double bonds in carbon chain. Solid at room temperature. Sources: animal fats (butter, lard, ghee), palm oil, coconut oil. Raise LDL ("bad cholesterol") → risk of atherosclerosis, heart disease.
Monounsaturated (MUFAs): One double bond. Olive oil, avocado, nuts. Neutral to LDL; raise HDL — heart-protective.
Polyunsaturated (PUFAs): Multiple double bonds. Sunflower, soybean, fish oils. Include essential fatty acids: Omega-3 (α-linolenic acid — anti-inflammatory, brain health) and Omega-6 (linoleic acid). Raise HDL, lower LDL.
Trans fats: Artificially hydrogenated oils (vanaspati, margarine). Worst — raise LDL AND lower HDL. FSSAI banned trans fats >2% in foods from 2022.
🩸 Cholesterol — LDL vs HDL
Cholesterol is not all bad — it is essential: builds cell membranes, precursor to steroid hormones (testosterone, cortisol, oestrogen), precursor to Vitamin D, component of bile acids.
LDL (Low-Density Lipoprotein) = "Bad cholesterol." Carries cholesterol FROM liver TO tissues. If excess → deposits in arterial walls → atherosclerosis → heart attack, stroke.
HDL (High-Density Lipoprotein) = "Good cholesterol." Carries cholesterol FROM tissues BACK TO liver for disposal. Higher HDL = lower heart disease risk.
VLDL: Carries triglycerides from liver. High levels linked to heart disease.
Memory: LDL = Lethal (bad). HDL = Healthy (good). Saturated fats ↑ LDL. Unsaturated fats ↑ HDL. Trans fats = worst (↑ LDL + ↓ HDL).
⚙️ Functions of Fats
- Energy store (9 kcal/g)
- Absorb fat-soluble vitamins A, D, E, K
- Insulation (subcutaneous fat)
- Organ protection (cushions kidneys, heart)
- Cell membrane component (phospholipids)
- Hormone production (steroid hormones)
- Brain development (~60% of brain is fat)
- Improves food palatability
🥗 Sources
- Healthy: Olive oil, mustard oil, groundnut oil, fish (omega-3), nuts, seeds, avocado
- Moderate: Dairy, eggs, lean meat, coconut oil
- Unhealthy: Butter, lard, palm oil (high SFA); vanaspati, margarine (trans fats)
- Oily seeds: Sesame, sunflower, flaxseed (good omega-3 source)
- FSSAI advice: limit saturated fat <10% of energy; avoid trans fats
🏥 Disorders
- Atherosclerosis: plaque in arteries → heart attack, stroke
- Obesity: excess fat storage
- Hypercholesterolaemia: high blood cholesterol
- NAFLD: Non-alcoholic fatty liver disease (rising in India)
- Essential FA deficiency: skin problems, poor wound healing, brain issues
- Fat deficiency: malabsorption of vitamins A, D, E, K → deficiency diseases
Section 05 — Micronutrient 1
🍊 Vitamins — The Regulatory Micronutrients
📌 Definition: Vitamins are organic compounds required in tiny amounts that the body cannot synthesise (or cannot make enough of) and must obtain from diet. They do NOT provide energy but are essential co-enzymes and co-factors for metabolic reactions. Discovered in early 20th century — Casimir Funk coined the term "vitamine" (1912). Two types: Fat-soluble (A, D, E, K — stored in body fat; risk of toxicity if excess) and Water-soluble (B-complex, C — not stored, excreted in urine; must consume daily).
| Vitamin | Type | Key Function | Sources | Deficiency Disease / Symptom |
|---|
| A (Retinol) | Fat-soluble | Vision (especially night vision); skin; immune function; epithelial tissue maintenance | Liver, eggs, dairy, carrots, sweet potato, yellow/red fruits (β-carotene — provitamin A) | Xerophthalmia → blindness; Night blindness; growth retardation; increased infections |
| D (Calciferol) | Fat-soluble | Calcium & phosphorus absorption; bone mineralisation; immune regulation | Fish liver oil, eggs, milk; synthesised in skin by sunlight (UV-B) | Rickets (children — soft, deformed bones); Osteomalacia (adults — soft bones); Osteoporosis |
| E (Tocopherol) | Fat-soluble | Antioxidant — protects cell membranes from oxidative damage; immune function; skin | Nuts, seeds, wheat germ oil, sunflower oil, green vegetables | Rare; peripheral neuropathy, haemolytic anaemia in infants, infertility |
| K (Phylloquinone) | Fat-soluble | Blood clotting (synthesis of clotting factors II, VII, IX, X — prothrombin); bone health | Dark green leafy vegetables (spinach, kale, broccoli); also made by gut bacteria | Bleeding disorder (haemorrhage) — prolonged clotting time; in newborns: Vitamin K deficiency bleeding (VKDB) |
| B1 (Thiamine) | Water-soluble | Carbohydrate metabolism; nerve function | Whole grains, legumes, pork, nuts | Beriberi — peripheral neuropathy (dry beriberi), heart failure (wet beriberi); Wernicke encephalopathy (alcoholics) |
| B2 (Riboflavin) | Water-soluble | Energy metabolism (FAD/FMN co-enzyme); tissue repair | Dairy, eggs, meat, green vegetables | Ariboflavinosis — cracked lips (cheilosis), swollen tongue (glossitis), eye sensitivity |
| B3 (Niacin / PP) | Water-soluble | Energy metabolism (NAD/NADP co-enzyme); DNA repair; skin | Meat, fish, poultry, peanuts, whole grains | Pellagra — 4 Ds: Dermatitis, Diarrhoea, Dementia, Death |
| B6 (Pyridoxine) | Water-soluble | Amino acid metabolism; neurotransmitter synthesis (serotonin, dopamine); immune function | Meat, fish, potatoes, bananas, chickpeas | Peripheral neuropathy, dermatitis, anaemia, depression |
| B9 (Folic acid / Folate) | Water-soluble | DNA synthesis; cell division; red blood cell formation; fetal neural tube development | Dark green vegetables, legumes, fortified cereals, liver | Neural tube defects (spina bifida, anencephaly) in fetus; Megaloblastic anaemia |
| B12 (Cobalamin) | Water-soluble | DNA synthesis; nerve function (myelin sheath); red blood cell formation; requires intrinsic factor for absorption | Animal products ONLY (meat, fish, eggs, dairy); NOT in plants | Pernicious anaemia; subacute combined degeneration of spinal cord; vegans at high risk |
| C (Ascorbic acid) | Water-soluble | Collagen synthesis (connective tissue); iron absorption; antioxidant; immune function; wound healing | Citrus fruits, guava, amla (highest source!), bell peppers, broccoli, tomatoes | Scurvy — bleeding gums, poor wound healing, perifollicular haemorrhages, joint pain |
📌 Key UPSC Facts on Vitamins:
• Vitamin D: Only vitamin synthesised in the body (via sunlight). Urban India has high Vitamin D deficiency due to indoor lifestyle, pollution blocking UV-B.
• Vitamin B12: Only vitamin not found in any plant food — strict vegans need supplements. India's vegetarian majority is at risk.
• Vitamin K: Newborns given Vitamin K injection at birth to prevent VKDB (Vitamin K Deficiency Bleeding).
• Folic acid (B9): All pregnant women advised 400 mcg/day supplementation — prevents neural tube defects (NTDs). India has one of the highest NTD rates globally.
• Amla (Indian gooseberry): Richest natural source of Vitamin C (~600 mg/100g — 10x orange).
• Fat-soluble vitamins (A, D, E, K): Excess accumulates in liver → toxicity (hypervitaminosis A, D especially dangerous). Water-soluble vitamins (B, C) are excreted in urine — overdose rare.
Section 06 — Micronutrient 2
🦴 Minerals — The Structural & Regulatory Elements
📌 Definition: Minerals are inorganic elements required by the body in small amounts for structural and regulatory functions. Macrominerals (needed >100 mg/day): Calcium, Phosphorus, Magnesium, Sodium, Potassium, Chloride, Sulphur. Trace minerals/microminerals (needed <100 mg/day): Iron, Iodine, Zinc, Fluoride, Selenium, Copper, Chromium.
🩸 Iron (Fe)
Functions: Component of haemoglobin (carries O₂ in red blood cells — iron gives blood its red colour) and myoglobin (oxygen store in muscles). Also part of oxidative enzymes (cytochromes).
Absorption: Haem iron (from meat/fish — Fe²⁺) is much better absorbed (15–35%) than non-haem iron (from plants — Fe³⁺, absorbed only 2–10%). Vitamin C enhances non-haem iron absorption. Tannins (tea, coffee) and phytates (cereals) inhibit iron absorption.
Sources: Red meat, organ meats (liver), fish, dark leafy greens (spinach), legumes, fortified cereals.
Deficiency → Iron Deficiency Anaemia (IDA): Most common nutritional deficiency globally and in India. Symptoms: fatigue, pallor, breathlessness, impaired cognition, low birth weight, reduced immunity.
India data: NFHS-5: 57% of women aged 15-49 anaemic; 67% children under 5 anaemic. Anemia Mukt Bharat (2018) aims to reduce anaemia 3% annually.
🦷 Calcium (Ca) & Phosphorus (P)
Functions of Calcium:
• Forms bones and teeth (99% of body calcium is in bones)
• Muscle contraction (including heart muscle)
• Nerve transmission
• Blood coagulation (clotting)
• Absorption of Vitamin B12
• Pancreatic enzyme activity
Functions of Phosphorus:
• Bones and teeth (85% in skeleton)
• ATP (energy currency) — adenosine triphosphate
• DNA and RNA backbone (phosphodiester bonds)
• Buffers blood pH
Calcium:Phosphorus ratio matters: Imbalance → calcium leaches from bones → Rickets (children) and Osteoporosis (adults).
Sources: Milk and dairy (best balanced Ca:P source), dark leafy greens, sesame seeds, ragi (finger millet — highest plant Ca source).
🫶 Iodine (I)
Functions: Essential component of thyroid hormones (T3 — triiodothyronine and T4 — thyroxine), which regulate:
• Metabolic rate
• Growth and development
• Brain development (critical in fetus and infants)
Deficiency diseases:
• Goitre — enlarged thyroid gland (swollen neck)
• Cretinism — severe intellectual disability, stunted growth in babies (if mother is iodine-deficient during pregnancy)
• Hypothyroidism — slow metabolism, weight gain, fatigue
• Fetal iodine deficiency: increased prenatal & postnatal mortality; intellectual impairment
Sources: Seafood, iodine-rich soil foods, seaweed.
India policy: Mandatory iodisation of all table salt (Universal Salt Iodisation — USI) — one of India's most successful public health interventions.
🦠 Zinc (Zn) & Other Key Minerals
Zinc: Immune function, wound healing, protein synthesis, enzyme co-factor, taste and smell, growth. Deficiency → growth retardation, diarrhoea (leading cause of child death), poor immunity. ORS (Oral Rehydration Salt) now includes zinc supplementation (WHO/UNICEF recommendation).
Sodium (Na): Fluid balance, nerve impulse, blood pressure. Excess → hypertension. RDA: <5g salt/day (WHO). India has high sodium intake from pickles, processed foods.
Potassium (K): Counteracts sodium — lowers blood pressure. Sources: bananas, potatoes, tomatoes. High-K diet protective against hypertension and stroke.
Fluoride (F): Strengthens tooth enamel, prevents dental caries. Excess → fluorosis (mottled teeth, skeletal deformities). Excess fluoride in groundwater is a problem in Rajasthan, Gujarat, Andhra Pradesh, and other states in India.
| Nutrient | Deficiency Disease/Condition | Key Sign/Symptom | Affected Group |
|---|
| Carbohydrate+Protein (severe) | Marasmus (energy deficiency) | Severe muscle wasting, wrinkled skin, "old man face", no oedema | Infants <1 year |
| Protein (with some calories) | Kwashiorkor | Oedema (swollen belly), fatty liver, hair changes, skin lesions, apathy | Children 1–3 years |
| Iron | Iron Deficiency Anaemia (IDA) | Pallor, fatigue, low haemoglobin (<12g/dL women, <13 men), spoon-shaped nails (koilonychia) | Women, children, pregnant |
| Vitamin A | Xerophthalmia; Night blindness | Dry eyes, Bitot's spots, corneal ulcers → blindness | Children <5 years |
| Vitamin B1 (Thiamine) | Beriberi | Dry: peripheral neuritis; Wet: heart failure, oedema; Wernicke encephalopathy (alcoholics) | Rice-eating populations; alcoholics |
| Vitamin B3 (Niacin) | Pellagra | 4 Ds: Dermatitis (sun-sensitive skin rash), Diarrhoea, Dementia, Death | Corn/sorghum-based diets |
| Vitamin B9 (Folic Acid) | Neural tube defects (NTD); megaloblastic anaemia | Spina bifida, anencephaly in fetus; large abnormal RBCs | Pregnant women; fetuses |
| Vitamin B12 | Pernicious anaemia; nerve damage | Megaloblastic anaemia + subacute combined degeneration (posterior/lateral spinal cord) | Vegans; elderly (↓ intrinsic factor) |
| Vitamin C | Scurvy | Bleeding gums (first sign), poor wound healing, perifollicular haemorrhages, joint pain | Diets low in fresh fruits/vegetables |
| Vitamin D | Rickets (children); Osteomalacia (adults) | Soft bones, bow legs, delayed teeth, bony deformities (rickets); bone pain, muscle weakness (osteomalacia) | Children (rickets); adults (osteomalacia) |
| Vitamin K | Haemorrhagic disease / VKDB | Prolonged bleeding, inability to clot; in newborns: internal bleeding | Newborns; those on antibiotics (kill gut bacteria) |
| Iodine | Goitre; Cretinism; Hypothyroidism | Enlarged thyroid (neck swelling); intellectual disability, stunting (cretinism) | Populations in iodine-poor areas; pregnant women |
| Calcium | Rickets; Osteoporosis; Tetany | Bone deformities (rickets); fractures (osteoporosis); muscle cramps/spasms (tetany) | Children; post-menopausal women; elderly |
| Zinc | Growth retardation; poor immunity | Dwarfism, diarrhoea, skin lesions, poor wound healing, anosmia (loss of smell) | Children; severe malnutrition |
Section 07 — Current Affairs
📰 Current Affairs 2024–2026 (Fact-Verified)
2024 — 🌍 GLOBAL
Global Hunger Index 2024 — India ranks 105th out of 127 nations
📊 India's rank:105th out of 127 countries in GHI 2024, score of 27.3 — classified as "Serious" hunger level. Worse than Bangladesh (84th), Nepal (68th), and Sri Lanka (56th).
🧒 Children:Child stunting: 35.5% (low height for age — chronic undernutrition). Child wasting: 18.7% — highest wasting rate in the world (acute undernutrition; low weight for height). Over 21 million wasted children under 5 in India.
👩 Women:Over 53.7% of women aged 15–49 are anaemic (NFHS-5 / SOFI 2025). India has ~203 million anaemic women. Despite Anemia Mukt Bharat, anaemia rates remain stubbornly high.
🤔 GHI controversy:Indian government contests GHI methodology — argues child-centric indicators (wasting, stunting) don't represent overall hunger; undernourishment estimate based on only 3,000 survey respondents. GHI 2025: India ranked 102nd out of 123 countries (score 25.8).
📚 UPSC angle:GHI 4 components: Undernourishment + Child stunting + Child wasting + Child mortality (under 5). India's "double burden": undernutrition + rising obesity (overweight children rose 2.7M→4.2M in 2012–2024; obese adults doubled from 33.6M to 71.4M).
2024 — 🇮🇳 INDIA POLICY
POSHAN 2.0 / Saksham Anganwadi & Fortified Rice — India's Nutrition Initiatives
🍚 Fortified rice:India achieved 100% distribution of fortified rice across all food security schemes (PDS — Public Distribution System, ICDS — Integrated Child Development Services, PM POSHAN — mid-day meals) by March 2024. Rice fortified with Iron, Folic Acid, and Vitamin B12 — targeting anaemia and micronutrient deficiencies. ~80 crore beneficiaries covered.
🌸 POSHAN 2.0:Merged schemes: Anganwadi Services + Scheme for Adolescent Girls + POSHAN Abhiyaan = Saksham Anganwadi and POSHAN 2.0 (2021). Targets children 0–6, adolescent girls, pregnant women, lactating mothers. 10+ crore beneficiaries by 2024. Real-time POSHAN Tracker for monitoring.
🩸 Anemia Mukt Bharat:Launched 2018. Aims to reduce anaemia 3 percentage points annually. Provides Iron-Folic Acid (IFA) supplementation to children, adolescent girls, pregnant/lactating women. Also includes deworming (worms cause iron loss) and dietary diversification counselling.
☀️ Vitamin A Programme:Ministry of Health: biannual Vitamin A supplementation for children aged 1–5 years under National Immunization Schedule. Prevents childhood blindness and reduces child mortality (Vitamin A deficiency increases susceptibility to infections — measles, diarrhoea).
🌾 Millets & nutrition:India declared 2023 as International Year of Millets (IYoM) — UN resolution. Millets (jowar, bajra, ragi) are rich in iron, calcium, fibre, and protein — ideal for addressing micronutrient deficiency. Ragi highest plant source of calcium (~344 mg/100g).
📚 UPSC angle:PM POSHAN; POSHAN 2.0; Saksham Anganwadi; Anemia Mukt Bharat; fortified rice (Iron + Folic Acid + B12); ICDS; PMGKAY (free foodgrains 81 crore people, extended to 2029); IYoM 2023; Universal Salt Iodisation; FSSAI trans fat ban 2022.
2023 — 🌍 LANCET STUDY
Lancet Global Health: Global Micronutrient Deficiency — A "Hidden Hunger" Crisis
📄 Study:Published in Lancet Global Health — analysed micronutrient intake in 185 countries across all age groups. Found that majority of the global population does not meet the daily recommended intake of several key micronutrients.
🔍 Most deficient:Globally, the most inadequately consumed micronutrients are: Iodine, Vitamin E (tocopherol), Calcium, Iron, Riboflavin (B2), and Folate (B9). South Asia (including India) shows particularly high deficiency in iron, zinc, calcium, and folate.
💡 Hidden hunger:"Hidden hunger" refers to micronutrient deficiency even when sufficient calories are consumed — a person may not feel hungry but is nutritionally deficient. Affects cognitive development, immunity, productivity. India has a massive hidden hunger problem — calorie intake is adequate but diet is not diverse enough for micronutrients.
📚 UPSC angle:Hidden hunger; double burden of malnutrition; Lancet Global Health; micronutrient inadequacy; dietary diversity vs calorie sufficiency; India's cereal-based diet; need for food fortification and diversification.
Section 08 — PYQs & MCQs
📝 Previous Year Questions & Practice MCQs
PYQ — Prelims 2018 Consider the following statements:
1. Vitamin B12 cannot be obtained from plant sources.
2. Folic acid deficiency during pregnancy can cause neural tube defects in the fetus.
3. Iron from animal sources (haem iron) is absorbed better than iron from plant sources (non-haem iron).
4. Vitamin C deficiency causes Pellagra.
a) 1, 2 and 3 only
b) 2 and 4 only
c) 1, 2 and 3 only (Statement 4 is wrong)
d) 1, 2, 3 and 4
Statement 1 ✓ — Vitamin B12 (cobalamin) is found ONLY in animal products — meat, fish, eggs, dairy. No plant food naturally contains B12. This is why strict vegetarians and vegans are at risk of B12 deficiency and require supplementation. Some seaweeds contain B12 analogues, but they are not bioavailable. Statement 2 ✓ — Folic acid (Vitamin B9) is essential for DNA synthesis and rapid cell division in the developing fetus. Deficiency during the first 28 days of pregnancy (neural tube closure period) causes neural tube defects: spina bifida (incomplete spinal closure) and anencephaly (absent skull/brain). All women planning pregnancy should take 400 mcg folic acid daily. Statement 3 ✓ — Haem iron (found in animal blood proteins, myoglobin, haemoglobin) is in the ferrous form (Fe²⁺) and absorbed at 15–35%. Non-haem iron (plant sources — Fe³⁺) is absorbed at only 2–10%. Vitamin C converts Fe³⁺ to Fe²⁺, enhancing non-haem iron absorption. Tannins (tea) and phytates (cereals) inhibit it. Statement 4 ✗ — Classic trap: Pellagra is caused by NIACIN (Vitamin B3) deficiency, not Vitamin C. Vitamin C deficiency causes SCURVY (bleeding gums, poor wound healing). Answer: (c).
PYQ — Prelims 2021 With reference to nutritional deficiencies in India, which of the following pairs of nutrient and deficiency disease is/are correctly matched?
1. Iron — Goitre
2. Iodine — Cretinism
3. Vitamin A — Scurvy
4. Vitamin C — Scurvy
a) 1 and 2 only
b) 2 and 3 only
c) 2 and 4 only
d) 1, 2 and 4 only
Pair 1 ✗ — Iron deficiency causes ANAEMIA (Iron Deficiency Anaemia — IDA), not goitre. Goitre is caused by IODINE deficiency. Pair 2 ✓ — Iodine deficiency causes Goitre (enlarged thyroid), Cretinism (severe intellectual disability and stunted growth in babies born to iodine-deficient mothers), and Hypothyroidism. Cretinism is the most severe consequence — iodine is essential for thyroid hormone synthesis, which is critical for fetal brain development. Pair 3 ✗ — Vitamin A deficiency causes XEROPHTHALMIA (dry eyes, corneal ulcers → blindness) and Night blindness — NOT scurvy. Also causes growth retardation and reduced immunity. Pair 4 ✓ — Vitamin C (ascorbic acid) deficiency causes SCURVY. Vitamin C is essential for collagen synthesis. Without it, collagen breaks down → bleeding gums (first sign), perifollicular haemorrhages, poor wound healing, joint pain. Answer: (c) — only pairs 2 and 4 are correctly matched.
Q1 Which of the following are fat-soluble vitamins?
a) Vitamins A, B, C and D
b) Vitamins A, D, E and K
c) Vitamins A, C, D and K
d) Vitamins B complex, D and E
Fat-soluble vitamins: A, D, E, K — these are soluble in fats/oils and stored in the body's fatty tissues and liver. Because they are stored, they are NOT required every day (unlike water-soluble vitamins). However, excess accumulation can cause toxicity — hypervitaminosis A and hypervitaminosis D are dangerous. Memory: ADEK or "All Dogs Eat Kibble." Water-soluble vitamins: B-complex (B1, B2, B3, B5, B6, B7, B9, B12) and Vitamin C — dissolve in water, excreted in urine, need daily intake, toxicity rare. Answer: (b).
Q2 Consider the following statements about India's nutrition situation:
1. India has the highest rate of child wasting (low weight for height) in the world as per 2024 data.
2. The Global Hunger Index 2024 categorises India in the "alarming" category.
3. Fortified rice distributed under PDS includes Iron, Folic Acid, and Vitamin B12.
4. POSHAN 2.0 merged several nutrition schemes including POSHAN Abhiyaan and Anganwadi Services.
a) 1, 2 and 3 only
b) 1, 3 and 4 only
c) 2, 3 and 4 only
d) 1, 2, 3 and 4
Statement 1 ✓ — As per UN SOFI 2025 report, India has 18.7% child wasting rate — the HIGHEST in the world (over 21 million wasted children under 5). This reflects acute malnutrition. Statement 2 ✗ — Key trap: GHI 2024 categorises India as "SERIOUS" (score 27.3, rank 105/127) — NOT "Alarming." GHI categories: Low (0-9.9), Moderate (10-19.9), Serious (20-34.9), Alarming (35-49.9), Extremely Alarming (≥50). Statement 3 ✓ — India's fortified rice under PDS, ICDS and PM POSHAN contains Iron, Folic Acid (B9), and Vitamin B12 — specifically targeting anaemia and micronutrient deficiencies. 100% distribution achieved March 2024. Statement 4 ✓ — POSHAN 2.0 (now Saksham Anganwadi and POSHAN 2.0, launched 2021) merged: (1) POSHAN Abhiyaan, (2) Anganwadi Services, (3) Scheme for Adolescent Girls. Targets children 0-6, adolescent girls, pregnant and lactating women. Answer: (b).
Q3 Which of the following statements about Kwashiorkor and Marasmus is correct?
a) Both Kwashiorkor and Marasmus result from carbohydrate deficiency alone
b) Marasmus is characterised by oedema (swollen belly) while Kwashiorkor shows muscle wasting
c) Kwashiorkor results from protein deficiency (with some caloric intake) and shows oedema; Marasmus results from severe energy-protein deficiency and shows wasting without oedema
d) Kwashiorkor occurs only in adults; Marasmus occurs only in infants under 6 months
Option (c) is correct. Kwashiorkor (the name comes from Ghanaian language — "disease the older child gets when next baby is born") occurs when a child receives adequate calories (usually from carbohydrates) but grossly insufficient protein. Without plasma proteins, fluid accumulates in tissues → oedema (characteristically swollen abdomen — "moon belly"). Other features: fatty liver (liver cannot make lipoproteins to export fat), skin lesions, hair changes (flag sign — alternating bands of light/dark), apathy, muscle weakness (though muscles not severely wasted due to adequate calories). Marasmus = Greek for "wasting." Results from severe deficiency of BOTH protein AND energy. Body burns all reserves — fat and muscle — leading to severe wasting, emaciated appearance ("skin and bones"), wrinkled skin, "old man face." Crucially: NO oedema (unlike Kwashiorkor), because body reduces all protein production equally, so osmotic pressure balance is maintained proportionally. Both typically affect children 6 months to 5 years. Option (b) is wrong — it's the reverse. Answer: (c).
Section 09
🧠 Memory Aid — Lock These In
🔑 Nutrients — All Critical Facts for UPSC
ENERGY
Carbs = 4 kcal/g | Protein = 4 kcal/g | Fat = 9 kcal/g (highest). Carbs = preferred fuel (especially brain). Fat = 2x+ energy density. No energy from vitamins or minerals.
CARBS
Simple (fast-absorbing, high GI): glucose, fructose, sucrose, lactose. Complex (slow, low GI): starch (plant), glycogen (animal), cellulose (fibre — not digestible). Glycogen in liver (~100g) + muscles (~400g). Surplus carbs → fat. GI <55 = low GI (preferred for diabetics).
PROTEIN
20 amino acids total; 9 ESSENTIAL (cannot make in body). Complete protein: meat, fish, eggs, dairy, SOY (only plant). Incomplete: most plants. Rice + lentils = complete. Kwashiorkor = protein deficiency (with oedema). Marasmus = energy + protein deficiency (wasting, NO oedema). All enzymes = proteins.
FATS
Saturated = animal fats, palm oil → ↑ LDL (bad). Unsaturated = plant/fish oils → ↑ HDL (good). Trans fats = worst (↑LDL + ↓HDL) — FSSAI banned >2% 2022. Essential FAs: Omega-3 (fish), Omega-6 (plant oils). Fat-soluble vitamins: A, D, E, K — need fat for absorption. LDL = Lethal. HDL = Healthy.
VITAMINS
Fat-soluble (stored, toxic if excess): A, D, E, K — mnemonic "ADEK / All Dogs Eat Kibble." Water-soluble (daily needed, excreted): B-complex + C. Vitamin D: ONLY one synthesised in body (sunlight/UV-B). Vitamin B12: NOT in any plant — vegans must supplement. Amla: richest natural Vitamin C (600mg/100g). Vitamin K: blood clotting; newborns get injection.
DEFICIENCIES
Iron → Anaemia (IDA). Iodine → Goitre / Cretinism. Vitamin A → Xerophthalmia / Night blindness. Vitamin B1 → Beriberi. Vitamin B3 → Pellagra (4Ds: Dermatitis, Diarrhoea, Dementia, Death). Vitamin B9 → Neural tube defects (NTD). Vitamin C → Scurvy (bleeding gums FIRST sign). Vitamin D → Rickets (children) / Osteomalacia (adults). Calcium → Rickets / Osteoporosis / Tetany.
TRAPS 🪤
• Pellagra = B3 deficiency (NOT Vitamin C). • Scurvy = Vitamin C (NOT B3). • Goitre = Iodine (NOT iron). • Kwashiorkor = OEDEMA (swollen belly). Marasmus = NO oedema (wasting). • Fat-soluble vitamins = stored → can be toxic if excess. • Haem iron (animal) absorbed BETTER than non-haem (plant). • Vitamin C ENHANCES non-haem iron absorption. • B12 = animal products ONLY — no plant source. • Ragi = highest plant calcium (344 mg/100g).
CURRENT AFFS
GHI 2024: India 105/127, "Serious," wasting 18.7% (world's highest). GHI 2025: India 102/123. Fortified rice 100% distributed March 2024 (Iron + Folic Acid + B12). POSHAN 2.0 (Saksham Anganwadi 2021). Anemia Mukt Bharat 2018 (IFA supplementation, deworming). IYoM 2023 — millets nutrition push. FSSAI trans fat ban 2022. Lancet: iodine, Vit E, calcium, iron, B2, folate most deficient globally.
Section 10
❓ FAQs — Concept Clarity
Why do India's urban populations have Vitamin D deficiency despite abundant sunlight?
Vitamin D is unique — it's the only vitamin primarily synthesised in the body when skin is exposed to UV-B rays from sunlight. Yet urban India paradoxically has very high Vitamin D deficiency (estimated 70-90% of urban Indians are deficient). Several factors explain this: (1) Indoor lifestyle — office work, air-conditioned environments mean minimal sun exposure during peak UV hours (10 AM–3 PM). (2) Air pollution — thick smog in cities like Delhi, Mumbai blocks UV-B radiation from reaching the skin. (3) Dark skin — higher melanin (skin pigment) in South Asians requires longer sun exposure to synthesise the same amount of Vitamin D as fair-skinned people. (4) Clothing — cultural practice of covering skin limits exposed skin area. (5) Low dietary intake — fish liver oil, eggs, and fortified milk are the main food sources; Indian diets are typically low in these. Consequence: widespread rickets in children, osteomalacia in adults, and emerging evidence linking Vitamin D deficiency to increased susceptibility to infections (including COVID-19), depression, and autoimmune diseases.
What is "double burden of malnutrition" and why is it important for India?
The "double burden of malnutrition" refers to a situation where a country simultaneously faces two types of nutritional problems: (1) Undernutrition — stunting, wasting, underweight, micronutrient deficiency. (2) Overnutrition — obesity, overweight, non-communicable diseases (diabetes, hypertension, heart disease). India's paradox: 37 million stunted children AND 71.4 million obese adults (2024 SOFI report). Between 2012-2024, overweight children rose from 2.7 million to 4.2 million. How this happens: Rural poor suffer undernutrition → move to cities → shift from traditional whole-food diet (millets, vegetables) to cheap, calorie-dense, nutrient-poor processed foods → adequate calories but micronutrient deficiency (hidden hunger) → weight gain with nutritional deficiency simultaneously. This is the "nutrition transition." For UPSC Mains: The double burden challenges policymakers because programmes addressing undernutrition (increasing calorie availability) may worsen obesity, and vice versa. Solutions: food fortification, dietary diversity promotion, millets, regulation of ultra-processed foods (India is considering a sugar/salt tax), and urban nutrition programmes beyond rural focus.
What is the difference between Rickets and Osteoporosis? Both involve bones — why do different nutrients cause them?
Rickets = bone disease in children. Caused by Vitamin D deficiency (most common), calcium deficiency, or phosphorus deficiency. Vitamin D is essential for calcium and phosphorus absorption in the intestine. Without Vitamin D, even if a child eats calcium-rich foods, the calcium cannot be absorbed properly. Result: inadequate mineral deposition in growing bones → soft, weak, deformed bones. Signs: bowed legs, knock-knees, pot belly (spinal deformity), delayed fontanelle closure, dental delay. Osteoporosis = bone disease in adults (especially post-menopausal women). Caused by long-term insufficient calcium intake, Vitamin D deficiency, oestrogen decline (after menopause), and aging. Unlike rickets (bones never mineralised properly), osteoporosis involves LOSS of previously mineralised bone mass → bones become porous, brittle, fracture-prone. Signs: hip fractures, vertebral fractures, loss of height. India has a massive and underdiagnosed osteoporosis problem — estimated 50 million affected. Osteomalacia = adult version of Rickets — soft bones due to Vitamin D deficiency in adults. Different from osteoporosis: bone matrix is present but poorly mineralised. Treatment: Vitamin D + calcium supplementation. For UPSC: Rickets = children + Vitamin D/calcium deficiency. Osteoporosis = adults + calcium loss + oestrogen decline. Osteomalacia = adult rickets (soft, not porous bones).
Section 11
🏁 Conclusion — UPSC Synthesis
🥗 Food Is Medicine — And Medicine Is Policy
India produces more milk than any other country, is the world's second-largest producer of wheat and rice, and yet 35.5% of its children are stunted and 18.7% are wasted — the highest wasting rate on Earth. This is not a food production problem; it is a nutrition, distribution, and dietary diversity problem. The country has enough calories but not enough micronutrients — a classic case of "hidden hunger" amplified by a cereal-heavy diet that is deficient in iron, zinc, calcium, Vitamin A, and B vitamins.
India's response — fortified rice, POSHAN 2.0, Anemia Mukt Bharat, millets promotion — represents the right direction. But the Lancet study reminds us that six micronutrients remain critically deficient globally. The biology of nutrients is fundamentally a public policy issue in India.
📋 Prelims Key Facts
⚡ Carbs=4 | Protein=4 | Fat=9 kcal/g
🔑 9 essential amino acids (must come from food)
🧪 ADEK = fat-soluble (stored, toxic if excess)
💧 B-complex + C = water-soluble (daily needed)
☀️ Vitamin D = ONLY one synthesised in body (sunlight)
🌿 B12 = NO plant source (vegans supplement)
🩸 LDL = bad; HDL = good; Trans fat = worst
🦷 Haem iron (animal) absorbed BETTER than non-haem
🍊 Amla = richest Vitamin C | Ragi = highest Ca (plant)
🇮🇳 GHI 2024: 105/127 "Serious" | wasting 18.7% = world's highest
🍚 Fortified rice: Fe + Folic Acid + B12 (100% by Mar 2024)
📝 Mains GS-II/III Topics
🏥 Double burden: undernutrition + obesity (India paradox)
🌾 Millets: IYoM 2023; nutritional value vs rice/wheat
👶 POSHAN 2.0 / Saksham Anganwadi — evaluate effectiveness
🩸 Anaemia in India: causes, Anemia Mukt Bharat
🍚 Food fortification: rice, salt iodisation — policy analysis
💊 Hidden hunger: dietary diversity vs calorie sufficiency
⚖️ GHI controversy: India's objections to methodology
🌍 SDG 2 Zero Hunger — India's path by 2030
👩 Women's nutrition: iron, folic acid, anaemia — maternal health
