Nutrition and Health
🟢 Lite — Quick Review (1h–1d)
Rapid summary for last-minute revision before your NEET PG exam.
Nutrition and Health — Key Facts
Macronutrients
- Carbohydrates: 4 kcal/g — Main energy source
- Proteins: 4 kcal/g — Body building
- Fats: 9 kcal/g — Dense energy, essential fatty acids
Protein-Energy Malnutrition (PEM)
Marasmus: Calories AND protein deficiency
- Severe wasting, “old man” face, NO edema
- MUAC <115 mm
Kwashiorkar: Protein deficiency (calories adequate)
- Bilateral pitting edema, fatty liver, peeling skin
- Hair changes (flag sign)
Marasmic Kwashiorkar: Both — wasting + edema
Fat-Soluble Vitamins
| Vitamin | Deficiency | Functions |
|---|---|---|
| A | Night blindness → Xerophthalmia → Keratomalacia | Vision, epithelium |
| D | Rickets (children), Osteomalacia (adults) | Calcium absorption |
| E | Hemolytic anemia, neurological | Antioxidant |
| K | Bleeding disorders (PT prolonged) | Clotting factors |
⚡ NEET PG High-Yield: Marasmus vs Kwashiorkar (edema vs no edema) is a very common question.
🟡 Standard — Regular Study (2d–2mo)
Chapter: Nutrition and Health
1.1 Nutrients and Energy
Energy
- Carbohydrates: 4 kcal/g
- Proteins: 4 kcal/g
- Fats: 9 kcal/g
ICMR Recommended Dietary Allowances (Adult Male)
- Energy: 2,320 kcal (sedentary)
- Protein: 60g/day
- Fat: 20-30g/day
- Iron: 17mg
1.2 Protein-Energy Malnutrition (PEM)
Marasmus
Definition: Severe deficiency of both calories AND protein
Clinical Features:
- Severe muscle wasting
- No subcutaneous fat
- “Old man’s face” (wrinkled)
- No edema
- MUAC <115 mm
- Severe growth retardation
Kwashiorkar
Definition: Protein deficiency with adequate calories
Clinical Features:
- Bilateral pitting edema (hallmark)
- Fatty liver (fat deposition)
- Dermatosis (peeling skin)
- Hair changes: Sparse, thin, easily pluckable, flag sign (alternating bands)
- Subcutaneous fat preserved
- Apathy, irritability
Marasmic Kwashiorkar
Both wasting + edema → Most severe form
Classification (WHO)
SAM (Severe Acute Malnutrition):
- MUAC <115 mm OR
- Weight-for-height < -3 SD OR
- Bilateral pitting edema
1.3 Vitamins — Fat Soluble
Vitamin A (Retinol) — Very Important
Functions:
- Visual pigments (rhodopsin)
- Epithelial cell maintenance
- Immune function
Deficiency (Xerophthalmia Sequence):
- XN: Night blindness
- X1A: Conjunctival xerosis (dry, non-wettable)
- X1B: Bitot’s spots (foamy, triangular, temporal conjunctiva)
- X2: Corneal xerosis (dry, opaque cornea)
- X3: Corneal ulcer/keratomalacia
- XS: Scarring (permanent)
Treatment: Oral Vitamin A 200,000 IU (immediately, next day, 2 weeks)
Prevention: Supplementation 100,000 IU (6-11 mo), 200,000 IU (12-59 mo) every 6 months
Vitamin D (Cholecalciferol) — Important
Functions: Calcium and phosphorus absorption, bone mineralization
Deficiency — Rickets (children):
- Craniotabes (soft skull)
- Frontal bossing
- Rachitic rosary (enlarged costochondral junctions)
- Bow legs (genu varum) / Knock knees (genu valgum)
- Delayed fontanelle closure
- X-ray: Cupping and fraying of metaphyses
Deficiency — Osteomalacia (adults):
- Bone pain, muscle weakness
- Waddling gait
- Pseudofractures (Looser’s zones)
Vitamin K (Phylloquinone)
- Functions: Synthesis of clotting factors II, VII, IX, X
- Deficiency: Bleeding disorders, PT prolonged (Factor VII shortest half-life)
- Newborns receive Vitamin K injection at birth
Vitamin E (Tocopherol)
- Functions: Antioxidant, protects RBC membranes
- Deficiency: Hemolytic anemia (premature infants)
1.4 Vitamins — Water Soluble
B-Complex
| Vitamin | Deficiency | Functions |
|---|---|---|
| B1 (Thiamine) | Beriberi (wet: cardiac; dry: neurological) | Energy metabolism |
| B2 (Riboflavin) | Angular stomatitis, cheilosis | FAD in ETC |
| B3 (Niacin) | Pellagra (3 Ds + Death) | NAD in redox |
| B6 (Pyridoxine) | Peripheral neuropathy | Amino acid metabolism |
| B12 (Cobalamin) | Pernicious anemia, SCD | DNA synthesis |
| Folate | Megaloblastic anemia, NTDs | DNA synthesis |
| C (Ascorbic acid) | Scurvy (bleeding gums, petechiae) | Collagen synthesis |
Pellagra (Niacin Deficiency) — 4 Ds
- Dermatitis: Casal’s necklace (around neck)
- Diarrhea: Mouth ulcers, enteritis
- Dementia: Neurological symptoms
- Death: If untreated
Scurvy (Vitamin C Deficiency)
- Gum bleeding, swollen gums
- Petechiae, ecchymoses
- Perifollicular hemorrhages
- Poor wound healing
- Treatment: Vitamin C 500 mg/day
Folate Deficiency
- Megaloblastic anemia
- Neural tube defects (spina bifida) in fetus
- Prevention: Folic acid in pregnancy (400 μg/day)
B12 Deficiency
- Pernicious anemia (autoimmune against parietal cells)
- Subacute Combined Degeneration: Posterior columns + lateral corticospinal tracts
- Treatment: Hydroxocobalamin injection
1.5 Minerals
Iron
- RDA: Male 17mg, Female 21mg
- Functions: Hemoglobin (oxygen transport)
- Deficiency: Microcytic hypochromic anemia
- India: 50% women have anemia (NFHS-5)
- Prevention: IFA tablets (Ferrous sulfate + Folic acid)
Iodine
- RDA: 150 μg/day
- Functions: Thyroid hormone synthesis (T3, T4)
- Deficiency: Goiter, Hypothyroidism, Cretinism
- Prevention: Iodized salt (USI — Universal Salt Iodization)
Calcium
- RDA: 600 mg/day (adult)
- Functions: Bones, teeth, muscle, nerve
- Deficiency: Osteoporosis, tetany, rickets
Fluoride
- Optimal: 0.7-1.2 ppm in water
- Deficiency: Dental caries
- Excess: Fluorosis (dental: white spots; skeletal: osteosclerosis)
1.6 Obesity
Definition: BMI ≥ 25 kg/m² (Asian criteria)
- Overweight: 23-24.9
- Obese I: 25-29.9
- Obese II: ≥30
Comorbidities:
- Type 2 diabetes
- Hypertension, dyslipidemia
- CAD, stroke
- Sleep apnea, osteoarthritis
1.7 National Nutrition Programs
ICDS (1975):
- Anganwadi centres (14 lakh+)
- Services: Supplementary nutrition, immunization, health check-up, preschool
POSHAN Abhiyaan (2018):
- Reduce anemia, underweight, stunting, wasting
- Use of technology (ICDS-CAS app)
Mid-Day Meal Programme (PM-Poshan):
- Free cooked meal Class 1-8
National Iron Plus Initiative (NIPI):
- Children 6-59 months: Iron drops
- Adolescents: Weekly IFA tablets
- Pregnant women: Daily IFA
1.8 NEET PG High-Yield Points
⚡ Commonly Asked:
- Marasmus: Wasting, NO edema, calories+protein deficient
- Kwashiorkar: Edema, fatty liver, protein deficient
- Vitamin A sequence: Night blindness → Bitot’s spots → Corneal xerosis → Keratomalacia
- Rachitic rosary: Enlarged costochondral junctions in rickets
- Pellagra: 3 Ds + Death (niacin)
- Scurvy: Perifollicular hemorrhages, gum bleeding
- Folate: NTDs (spina bifida)
- B12: Pernicious anemia, subacute combined degeneration
- Iron: Microcytic hypochromic anemia
- ICDS services: Supplementary nutrition, immunization, health check-up