Core ConceptRead this first — the foundation of the topic
Core Concept
Diseases can be classified into two main types - nutritional deficiency diseases and infectious diseases. Nutritional diseases occur when the body lacks essential nutrients like vitamins, minerals, proteins, or carbohydrates. Infectious diseases are caused by pathogens like bacteria, viruses, fungi, or parasites
Key Rules for Deficiency Diseases
Each vitamin and mineral has specific deficiency symptoms. Vitamin deficiencies are categorized into fat-soluble (A, D, E, K) and water-soluble (B-complex, C) vitamins. Fat-soluble vitamins are stored in the body, while water-soluble vitamins need daily replenishment.
Formula BlockMemorise — at least one formula appears in every paper
• BMI = Weight (kg) / Height (m)²
• Daily Calorie Need = BMR × Activity Factor
• Protein Requirement = 1g per kg body weight (adults)
• Water Requirement = 35ml per kg body weight
Exam PatternsWhat examiners ask — read before attempting PYQs
SSC CGL consistently asks 2-3 questions on this topic. Common question types include vitamin deficiency diseases, food sources of nutrients, infectious disease causative agents, and prevention methods. Direct fact-based questions dominate, with occasional application-based scenarios.
ShortcutsUse these to save 30–60 seconds per question
- ABCD Method for Fat-Soluble Vitamins:
A = Anti-xerophthalmia (prevents night blindness)
B = Bone health (Vitamin D)
C = Clotting (Vitamin K)
D = Defense against oxidation (Vitamin E)
Worked ExampleSolve this step-by-step before moving on
1
Step 1
Analyze symptoms - bone-related problems indicate mineral deficiency
2
Step 2
Identify specific symptoms - weak bones + bow legs = Rickets
3
Step 3
Determine cause - Vitamin D and Calcium deficiency
4
Step 4
Prevention - Sunlight exposure, milk, fish, fortified foods
Answer: Rickets caused by Vitamin D deficiency, prevented by adequate sunlight and calcium-rich foods.
Worked Example 2: Match the pathogen with disease.
Question: Which pathogen causes Tuberculosis and how is it transmitted?
1
Step 1
Recall pathogen types - TB is bacterial disease
2
Step 2
Identify specific bacteria - Mycobacterium tuberculosis
3
Step 3
Transmission mode - Airborne droplets when infected person coughs/sneezes
4
Step 4
Prevention - BCG vaccination, proper ventilation, avoiding crowded places
Answer: Mycobacterium tuberculosis causes TB, transmitted through air droplets.
Shortcut for Vitamin C Sources: Remember 'CITRUS' - Citrus fruits, Indian gooseberry (amla), Tomatoes, Raw vegetables, Uncooked fruits, Sprouted grains.
Common Trap - The #1 mistake students make: Confusing night blindness with color blindness. Night blindness (nyctalopia) is caused by Vitamin A deficiency and is curable. Color blindness is a genetic condition affecting color perception and cannot be cured through nutrition. Always read the question carefully to distinguish between these two completely different conditions.
Another frequent error is mixing up Vitamin B1 (Beriberi) with Vitamin B12 (Pernicious anemia). Remember: B1 = Beriberi (nervous system), B12 = Blood-related anemia.
Prevention strategies follow three levels: Primary (vaccination, balanced diet), Secondary (early detection, screening), and Tertiary (treatment to prevent complications). This classification often appears in exam questions about public health measures.
Key Points to Remember
Vitamin A deficiency causes night blindness (xerophthalmia), found in carrots, milk, eggs
Vitamin D deficiency leads to rickets in children and osteomalacia in adults
Vitamin C deficiency causes scurvy, prevented by citrus fruits and fresh vegetables
Iron deficiency causes anemia, sources include green leafy vegetables and meat
Protein deficiency leads to kwashiorkor in children and marasmus in severe cases
BMI formula: Weight(kg) divided by Height(m) squared - normal range 18.5-24.9
Water-soluble vitamins (B, C) need daily intake, fat-soluble (A,D,E,K) are stored
Tuberculosis caused by Mycobacterium tuberculosis, spreads through air droplets
Malaria transmitted by female Anopheles mosquito, caused by Plasmodium parasite
Balanced diet contains 60% carbs, 20% fats, 20% proteins with vitamins and minerals
Exam-Specific Tips
Vitamin B1 (Thiamine) deficiency causes Beriberi disease affecting nervous system
Iodine deficiency leads to goiter and is prevented by iodized salt consumption
Pellagra is caused by Niacin (Vitamin B3) deficiency, common in maize-eating populations
Hemoglobin normal range: Men 14-17 g/dL, Women 12-15 g/dL
Scurvy is a disease caused by deficiency of which vitamin?
Practice 2easy
Beriberi is a disease caused by the deficiency of which B vitamin?
Practice 3easy
Which of the following vitamins is primarily responsible for the absorption of calcium in the human body?
Practice 4easy
Kwashiorkor is a form of protein malnutrition that primarily affects which age group?
Practice 5easy
Which of the following is a water-soluble vitamin that acts as a coenzyme in energy metabolism?
Practice 6medium
Which disease is caused by the deficiency of Vitamin C in the human body?
Practice 7medium
Which of the following vitamins is primarily responsible for calcium absorption in the human body and is synthesized when skin is exposed to sunlight?
Practice 8medium
Which of the following vitamins is synthesized by the human body when skin is exposed to sunlight?
Practice 9medium
Beriberi is a deficiency disease caused by the lack of which vitamin?
Practice 10medium
Kwashiorkor is a severe form of malnutrition primarily caused by deficiency of which nutrient?
Practice 11hard
Scurvy is caused by deficiency of which vitamin, and which body system is primarily affected?
Practice 12hard
Kwashiorkor is a severe form of protein-energy malnutrition. Which of the following is NOT a characteristic clinical feature of Kwashiorkor?
Practice 13hard
Which vitamin deficiency causes Beriberi, a disease affecting the nervous system and heart?
Practice 14hard
Pellagra is a disease caused by deficiency of Vitamin B3 (Niacin). Which of the following is the correct sequence of the '4 Ds' classically associated with Pellagra?
Practice 15hard
Which of the following vitamins is synthesized by the human body and does NOT require dietary intake for its primary production?
Practice 16hard
Which of the following statements about Rickets is INCORRECT?
60-Second Revision — Diseases & Nutrition
Remember: ABCD for fat-soluble vitamins - A(eyes), D(bones), E(antioxidant), K(clotting)
Formula: BMI = Weight/Height² - memorize normal range 18.5-24.9
Trap: Night blindness vs color blindness - first is nutritional, second is genetic
Quick recall: Citrus fruits for Vitamin C, milk for Calcium and Vitamin D
Disease agents: TB-bacteria, Malaria-parasite, Dengue-virus, all have different transmission
Deficiency diseases are preventable through balanced diet and lifestyle changes
Water-soluble vitamins need daily intake, fat-soluble vitamins are stored in body