Cracking competitive exams often hinges on mastering foundational knowledge, and understanding vitamins is absolutely crucial. This comprehensive guide provides everything you need to know about essential vitamins – their sources, functions, and the deficiency diseases linked to them – all tailored for your exam success.
What are Vitamins?
Vitamins are organic compounds that are essential for various bodily functions. They play crucial roles in maintaining health, supporting growth and development, and aiding in metabolism. Our bodies cannot produce most vitamins, so we must obtain them from our diet.
Key Functions of Vitamins:
Vitamins are essential nutrients that help the body function properly, and their main functions include:
- Cell Growth and repair: Vitamins help the body grow and maintenance of tissues..
- Wound healing: Vitamins help the body repair and heal wounds.
- Bone health: Vitamins help maintain healthy strong bones.
- Vision health: Vitamins are vital for healthy eyesight.
- Immune system: Vitamins help the immune system function properly.
- Energy: Some vitamins help the body get energy from food.
- Blood clotting: Some vitamins help the blood clot properly.
- Nerve health: Some vitamins help keep nerves healthy.
- Infection resistance: Some vitamins help the body resist infections
Types of Vitamins:
Vitamins are classified into two main groups based on their solubility:
- Fat-soluble – dissolve in fat
- Water-soluble – dissolve in water
- Fat-soluble vitamins: Vitamins A, D, E, and K are stored in the body’s fat tissues and can build up over time.
- Water-soluble vitamins: Vitamins B1 (thiamine), B2 (riboflavin), B3 (niacin), B6, B12, folate, biotin, and vitamin C are not stored in the body and need to be replenished regularly through diet.
Vitamins and Deficiency Diseases: Essential Knowledge for Competitive Exams
Essential Vitamins Chart: Chemical Names & Deficiency Diseases Explained
| Vitamins | Chemical Name | Deficiency Disease |
|---|---|---|
| Vitamin A | Retinal | Night-blindness, Hyperkeratosis, Keratomalacia |
| Vitamin B1 | Thiamine | Beriberi, Wernicke-Korsakoff syndrome |
| Vitamin B2 | Riboflavin | Ariboflavinosis |
| Vitamin B3 | Niacin, Niacinamide | Pellagra |
| Vitamin B5 | Pantothenic acid | Paresthesia |
| Vitamin B6 | Pyridoxine, Pyridoxamine, Pyridoxal | Anaemia, Peripheral neuropathy |
| Vitamin B7 | Biotin | Dermatitis, Enteritis |
| Vitamin B9 | Folic acid, Folinic acid | Megaloblastic anaemia; birth defects like neural tube defects during pregnancy |
| Vitamin B12 | Cyanocobalamin, Hydroxycobalamin, Methylcobalamin | Megaloblastic anaemia |
| Vitamin c | Ascorbic acid | Scurvy |
| Vitamin D | Cholecalciferol | Rickets, Osteomalacia |
| Vitamin E | Tocopherols, Tocotrienols | Rare deficiency; mild hemolytic anaemia in newborns |
| Vitamin K | Phylloquinone, Menaquinones | Bleeding diathesis |
List of Vitamins, Sources, and Deficiency Causes
Below is a breakdown of essential vitamins along with their sources and deficiency causes to ensure you’re fully prepared for exam questions on this topic.
1. Vitamin A (Retinol)
Functions / Role
Vitamin A is essential for:
- Maintaining healthy vision
- Supporting the immune system
- Promoting healthy skin and mucous membranes
- Assisting in growth and development of cells and tissues
Sources of Vitamin A
- Carrots
- Sweet potatoes
- Spinach
- Liver
- Eggs
Causes of Deficiency
- Inadequate intake of animal-based foods or leafy vegetables
- Chronic malnutrition
- Fat malabsorption disorders (since Vitamin A is fat-soluble)
Deficiency Diseases
- Night Blindness
→ Difficulty seeing in low-light or at night.
Commonly tested in exams as a key symptom of Vitamin A deficiency. - Xerophthalmia
→ Progressive eye dryness that may lead to corneal damage and blindness if untreated.
Summary
Students preparing for competitive exams should remember that Vitamin A deficiency causes night blindness and xerophthalmia. These are frequently asked in Biology, Nutrition, and General Science sections of TNPSC, SSC, UPSC, and NEET.
2. Vitamin B1 (Thiamine)
Functions / Role
Vitamin B1 is important for:
- Converting carbohydrates into energy
- Supporting proper function of the nervous system and muscles
- Aiding in brain development and focus
Sources of Vitamin B1
- Whole grains
- Pork
- Legumes
- Nuts
- Black beans
Causes of Deficiency
- High alcohol consumption
- Diets lacking whole or fortified grains
- Malabsorption disorders
Deficiency Diseases
Beriberi
→ Causes weakness, nerve inflammation, and heart-related symptoms
Commonly asked in exams as a result of Vitamin B1 deficiency
Wernicke-Korsakoff Syndrome
→ A neurological disorder related to chronic alcohol use and thiamine deficiency
Summary
Vitamin B1 deficiency leads to Beriberi and Wernicke-Korsakoff Syndrome. These are commonly tested in competitive exams under nutrition and general science sections of UPSC, SSC, and TNPSC.
3. Vitamin B2 (Riboflavin)
Functions / Role
Vitamin B2 helps in:
- Energy production and fat metabolism
- Maintaining healthy skin, eyes, and nervous system
- Assisting in the conversion of B6 and folate
Sources of Vitamin B2
- Milk and dairy products
- Eggs
- Almonds
- Leafy green vegetables
- Whole grains
Causes of Deficiency
- Low intake of dairy and grains
- Malabsorption in the digestive system
- Chronic dieting or undernutrition
Deficiency Disease
Ariboflavinosis
→ Cracked lips, sore throat, swollen tongue, itchy eyes
Exam questions often link Riboflavin deficiency to cheilosis and glossitis
Summary
Vitamin B2 deficiency causes Ariboflavinosis, leading to skin and mouth symptoms. Frequently tested in TNPSC and SSC exam biology sections.
4. Vitamin B3 (Niacin)
Functions / Role
Vitamin B3 is important for:
- Supporting the health of the skin, nerves, and digestive system
- Helping convert food into usable energy
- Maintaining normal cholesterol levels
Sources of Vitamin B3
- Poultry
- Fish
- Peanuts
- Whole grains
Causes of Deficiency
- Diets lacking niacin or tryptophan
- Chronic alcoholism
- Conditions that affect tryptophan absorption (e.g., Hartnup disease)
Deficiency Disease
Pellagra
→ Characterised by the “3 D’s”: Dermatitis, Diarrhea, and Dementia
Often included in exams as a hallmark disease of Vitamin B3 deficiency
Summary
Vitamin B3 deficiency causes Pellagra, identified by dermatitis, diarrhea, and dementia. This triad is frequently asked in UPSC, SSC, and TNPSC competitive exams.
5. Vitamin B5 (Pantothenic Acid)
Functions / Role
Vitamin B5 helps with:
- The synthesis of coenzymes for energy metabolism
- Producing hormones and neurotransmitters
- Supporting healthy skin and wound healing
Sources of Vitamin B5
- Avocados
- Chicken
- Mushrooms
- Broccoli
Causes of Deficiency
- Rare, but can occur with severe malnutrition
- Digestive disorders or poor absorption
Deficiency Disease
General Symptoms
→ Fatigue, irritability, numbness, and muscle cramps
Vitamin B5 deficiency is uncommon but can appear in exam questions as Pantothenic acid deficiency
Summary
Vitamin B5 (Pantothenic acid) deficiency is rare but may cause fatigue and cramps. Remember the chemical name “Pantothenic Acid” — it’s a common MCQ keyword.
6. Vitamin B6 (Pyridoxine)
Functions / Role
Vitamin B6 is necessary for:
- Producing neurotransmitters like serotonin and dopamine
- Supporting brain development and immune function
- Assisting in the production of hemoglobin in red blood cells
Sources of Vitamin B6
- Bananas
- Chickpeas
- Potatoes
- Fish (such as salmon)
Causes of Deficiency
- Chronic alcoholism
- Certain medications (e.g., isoniazid for TB)
- Poor diet or malabsorption
Deficiency Diseases
Anemia
→ Due to reduced hemoglobin production
Neurological Symptoms
→ Depression, irritability, confusion, and convulsions
Vitamin B6 is often prescribed alongside isoniazid (INH) to prevent these symptoms
Summary
Vitamin B6 deficiency causes anemia and nerve-related symptoms. Often tested in medical and nutrition-based exams, especially in connection with isoniazid therapy.
7. Vitamin B7 (Biotin)
Functions / Role
Vitamin B7 is essential for:
- Converting carbohydrates, fats, and proteins into energy
- Maintaining healthy hair, skin, and nails
- Supporting enzyme function in metabolism
Sources of Vitamin B7
- Eggs (especially yolk)
- Almonds
- Soybeans
- Whole grains
Causes of Deficiency
- Eating raw egg whites over a long period (due to avidin binding biotin)
- Rare genetic disorders
- Long-term antibiotic use affecting gut bacteria
Deficiency Diseases
Hair Loss and Skin Rash
→ Thinning hair, scaly red rash around eyes, nose, and mouth
Biotin is sometimes referred to as the “beauty vitamin” in exam questions due to its effect on hair and skin
Summary
Vitamin B7 (Biotin) deficiency can lead to hair loss and skin problems. Questions often test the chemical name Biotin and its link to raw egg white consumption.
8. Vitamin B9 (Folic Acid / Folate)
Functions / Role
Vitamin B9 is crucial for:
- DNA synthesis and repair
- Cell division, especially during pregnancy
- Preventing neural tube defects in fetal development
Sources of Vitamin B9
- Leafy green vegetables
- Beans and legumes
- Citrus fruits
- Fortified cereals
Causes of Deficiency
- Inadequate dietary intake
- Malabsorption (e.g., celiac disease)
- Increased need during pregnancy
Deficiency Diseases
Megaloblastic Anemia
→ Formation of abnormally large red blood cells causing fatigue
Neural Tube Defects (NTDs)
→ Inadequate folate during pregnancy may cause conditions like spina bifida
Folic acid supplementation during early pregnancy is a frequent exam topic
Summary
Vitamin B9 deficiency causes megaloblastic anemia and birth defects. Competitive exams often test the importance of folic acid in pregnancy
9. Vitamin B12 (Cobalamin)
Functions / Role
Vitamin B12 is needed for:
- Formation of red blood cells
- Proper functioning of the nervous system
- DNA synthesis and brain health
Sources of Vitamin B12
- Meat
- Fish
- Eggs
- Dairy products
- Fortified cereals (for vegetarians)
Causes of Deficiency
- Vegan diets without supplementation
- Pernicious anemia (autoimmune condition affecting absorption)
- Malabsorption disorders like Crohn’s disease
Deficiency Diseases
Pernicious Anemia
→ Fatigue, pale skin, and shortness of breath
Neurological Symptoms
→ Tingling in hands/feet, memory loss, confusion
Vitamin B12 deficiency is often discussed in exams related to strict vegetarianism or gastric issues
Summary
Vitamin B12 deficiency can cause anemia and neurological damage. It’s frequently tested in exams, especially in topics related to vegan diets and pernicious anemia.
10. Vitamin C (Ascorbic Acid)
Functions / Role
Vitamin C is essential for:
- Collagen synthesis for healthy skin, gums, and connective tissue
- Supporting the immune system
- Aiding in iron absorption
- Acting as a powerful antioxidant
Sources of Vitamin C
- Oranges
- Strawberries
- Bell peppers
- Broccoli
- Guavas
- Tomatoes
Causes of Deficiency
- Diet lacking fresh fruits and vegetables
- Smoking (increases vitamin C requirement)
- Prolonged stress or infections
Deficiency Disease
Scurvy
→ Symptoms include bleeding gums, fatigue, joint pain, and delayed wound healing
Often tested as a classic historical deficiency in sailors and low-fruit diets
Summary
Vitamin C deficiency causes scurvy, a key topic in science and nutrition-related exams. Also commonly asked in connection with collagen production and immunity.
11. Vitamin D (Cholecalciferol)
Functions / Role
Vitamin D is vital for:
- Calcium and phosphorus absorption
- Bone growth and mineralization
- Supporting immune health
Sources of Vitamin D
- Sunlight (synthesized by skin)
- Fatty fish (salmon, sardines)
- Fortified milk and cereals
- Egg yolks
Causes of Deficiency
- Lack of sun exposure
- Dark skin or indoor lifestyle
- Malabsorption issues (e.g., Crohn’s disease)
Deficiency Diseases
Rickets (Children)
→ Soft bones, bow legs, and skeletal deformities
Osteomalacia (Adults)
→ Bone pain, muscle weakness, fractures
Both diseases are frequently mentioned in relation to Vitamin D deficiency
Summary
Vitamin D deficiency causes rickets in children and osteomalacia in adults. These terms appear frequently in TNPSC, UPSC, NEET, and medical-related competitive exams.
12. Vitamin E (Tocopherols / Tocotrienols)
Functions / Role
Vitamin E is important for:
- Protecting cells from oxidative stress (antioxidant role)
- Supporting immune function
- Maintaining skin and eye health
Sources of Vitamin E
- Nuts and seeds (especially sunflower seeds)
- Almonds
- Spinach
- Sunflower oil
- Avocados
Causes of Deficiency
- Fat malabsorption disorders
- Rare genetic conditions
- Premature infants with low birth weight
Deficiency Diseases
Muscle Weakness & Coordination Problems
→ Due to oxidative damage in muscle tissues
Vision Impairment & Retinopathy
→ Particularly in premature babies
Male Infertility
→ Sometimes linked to Vitamin E deficiency in exam questions
Summary
Vitamin E deficiency can lead to muscle and eye issues. Known for its antioxidant role, it’s often included in multiple-choice exams under “cell protection” and “male infertility”.
13. Vitamin K (Phylloquinone / Menaquinones)
Functions / Role
Vitamin K is crucial for:
- Blood clotting (activates clotting factors)
- Supporting bone metabolism
- Preventing excessive bleeding
Sources of Vitamin K
- Leafy green vegetables (spinach, kale, cabbage)
- Broccoli
- Soybeans
- Fermented foods (natto)
- Fortified dairy products
Causes of Deficiency
- Long-term antibiotic use (kills gut bacteria that produce Vitamin K)
- Liver disease or fat malabsorption
- Newborns (due to low placental transfer)
Deficiency Diseases
Bleeding Diathesis
→ Easy bruising, nosebleeds, prolonged bleeding
Bone Weakness
→ Associated with lower bone density and fractures
Vitamin K is also known as the “anti-hemorrhagic vitamin” in many textbook definitions
Summary
Vitamin K deficiency leads to bleeding disorders and bone weakening. It’s often tested in exams under clotting-related disorders and newborn care.
How to Use This Guide in Your Exam Preparation
- Revise regularly: Make flashcards for each vitamin’s function, sources, and deficiency-related diseases.
- Practice mock tests: Many exams include direct questions about vitamin deficiencies and sources.
- Pay attention to key deficiencies: Focus on major diseases like night blindness, scurvy, rickets, and pellagra.
By mastering the information in this guide, you can confidently tackle vitamin-related questions in competitive exams and improve your chances of success!
For detailed guidance on essential vitamins and minerals, visit the official NHS vitamins and minerals information page.
Important Questions MCQs on Vitamins and Deficiency Diseases
Multiple choice questions on vitamins and minerals:
1. Which of the following vitamins helps in blood clotting in humans?
(MPPSC State Services Prelims – GS – 2022)
- Vitamin A
- Vitamin C
- Vitamin D
- Vitamin K
Show Answer & Explanation
Correct Answer: (D) Vitamin K
Important Points for Aspirants:
Vitamin K:
- Primary Function: Essential for the synthesis of several proteins, primarily prothrombin, which are crucial for the blood clotting process (coagulation). It acts as a coenzyme for an enzyme called gamma-glutamyl carboxylase, which modifies these clotting factors.
- Types: There are two main natural forms:
- Vitamin K1 (Phylloquinone): Found in green leafy vegetables.
- Vitamin K2 (Menaquinone): Produced by bacteria in the gut.
- Deficiency: Can lead to impaired blood clotting, causing easy bruising, bleeding gums, nosebleeds, and excessive bleeding from wounds. Newborns are often given a Vitamin K injection to prevent hemorrhagic disease of the newborn.
- Sources: Green leafy vegetables (spinach, kale, broccoli), cabbage, liver, eggs.
Other Options Explained:
- Vitamin A (Retinol): Crucial for good vision (especially in low light), immune function, cell growth, and healthy skin.
- Vitamin C (Ascorbic Acid): A powerful antioxidant; essential for collagen synthesis (important for skin, bones, and blood vessels), wound healing, and iron absorption. Its deficiency leads to scurvy.
- Vitamin D (Calciferol): Regulates calcium and phosphorus levels in the body, vital for strong bones and teeth. Synthesized in the skin upon exposure to sunlight. Deficiency can cause rickets in children and osteomalacia in adults.
2. Which nutrient is not present in significant amounts in milk?
(TNPSC Department Exam – Paper II Nutrition- 2022)
- Protein
- Vitamin A
- Vitamin D
- Vitamin C
Show Answer & Explanation
Correct Answer: (D) Vitamin C
Important Points for Aspirants:
Vitamin C in Milk: Cow’s milk naturally contains very low amounts of Vitamin C. Additionally, pasteurization processes and exposure to light further reduce its already limited content. That’s why milk is generally not considered a good source of Vitamin C.
Nutrients Present in Milk:
- Protein: Milk is an excellent source of high-quality protein (casein and whey), essential for growth and repair.
- Calcium: A primary source of calcium, vital for bone health.
- Vitamin A: Present, especially in whole milk.
- Vitamin D: Often fortified in milk in many countries to aid calcium absorption and prevent deficiency.
- B Vitamins: Contains various B vitamins like B2 (riboflavin) and B12.
- Other Minerals: Contains phosphorus, potassium, and magnesium.
3. Night blindness is caused by?
(TNPSC Department Exam – Paper II Nutrition- 2022)
- Vitamin A
- Vitamin D
- Vitamin C
- Vitamin E
Show Answer & Explanation
Correct Answer: (A) Vitamin A
Important Points for Aspirants:
Vitamin A Deficiency & Night Blindness: Night blindness (Nyctalopia) is one of the earliest symptoms of Vitamin A deficiency. Vitamin A is a critical component of rhodopsin, a light-sensitive pigment found in the rod cells of the retina, which are responsible for vision in low light.
Progressive Deficiency: If Vitamin A deficiency persists, it can lead to more severe eye conditions like xerophthalmia (dry eyes) and ultimately permanent blindness.
Functions of Other Vitamins (briefly):
- Vitamin D: Bone health, immune system.
- Vitamin C: Antioxidant, collagen formation, immunity.
- Vitamin E: Powerful antioxidant, protects cell membranes. Deficiency is rare but can lead to nerve damage.
4. Which of the following is a fat-soluble vitamin?
- Vitamin B
- Vitamin C
- Vitamin B12
- Vitamin K
Show Answer & Explanation
Correct Answer: (D) Vitamin K
Important Points for Aspirants:
Fat-Soluble Vitamins: These vitamins dissolve in fats and oils and are absorbed along with dietary fats. They are stored in the body’s fatty tissues and liver, meaning they can accumulate to toxic levels if taken in excessively large amounts (hypervitaminosis).
The four fat-soluble vitamins are: Vitamin A, Vitamin D, Vitamin E, and Vitamin K (A, D, E, K).
Water-Soluble Vitamins: These vitamins dissolve in water and are not stored in the body to a significant extent. Any excess is generally excreted in urine, so regular intake is crucial. Toxicity is rare with water-soluble vitamins.
These include: All B vitamins (B1, B2, B3, B5, B6, B7, B9, B12) and Vitamin C.
Analysis of Options:
- (A) Vitamin B: Water-soluble.
- (B) Vitamin C: Water-soluble.
- (C) Vitamin B12: A specific B vitamin, hence water-soluble.
- (D) Vitamin K: Fat-soluble.
5. The term vitamin was introduced by _________?
- Dr. Casimir Funk
- Louis Pasteur
- Robert Koch
- Alexander Fleming
Show Answer & Explanation
Correct Answer: (A) Dr. Casimir Funk
Important Points for Aspirants:
Dr. Casimir Funk: In 1912, Polish biochemist Casimir Funk coined the term “vitamine” (later dropped the ‘e’ to “vitamin”). He proposed that certain diseases like beriberi, scurvy, and pellagra were caused by the lack of specific vital nutrients, which he initially thought were “vital amines.”
Other Notable Scientists and Their Contributions:
- Louis Pasteur: Famous French microbiologist and chemist. Known for pasteurization (heat treatment to kill harmful microorganisms), developing vaccines for rabies and anthrax, and disproving spontaneous generation.
- Robert Koch: German physician and microbiologist. Known for isolating the bacteria causing anthrax, tuberculosis, and cholera. Developed “Koch’s Postulates,” a set of criteria to establish a causal relationship between a microbe and a disease.
- Alexander Fleming: Scottish physician and microbiologist. Famous for his accidental discovery of penicillin in 1928, the world’s first widely effective antibiotic.
Ready to ace your exams? Start by making flashcards for each vitamin, practice with our included MCQs, and focus on the key deficiencies highlighted. Master this guide, and you’ll be well on your way to confidently answering any vitamin-related question!.
Useful Link:
Discover in-depth information on essential vitamins, their health benefits, and deficiency symptoms on MedlinePlus – a trusted source from the U.S. National Library of Medicine.
Frequently Asked Questions about Vitamins for Exams
What are the main deficiency diseases caused by lack of vitamins?
Common vitamin deficiency diseases include Night Blindness (Vitamin A), Beriberi (Vitamin B1), Pellagra (Vitamin B3), Scurvy (Vitamin C), and Rickets (Vitamin D).
Which foods are good sources of Vitamin C for competitive exams?
Excellent sources of Vitamin C include oranges, strawberries, broccoli, and bell peppers. These are often tested as common sources in exams.
What are the typical symptoms of Vitamin B complex deficiency?
Deficiency in various B vitamins can lead to a range of symptoms, including Beriberi (B1), Ariboflavinosis (B2), Pellagra (B3), Anemia (B6, B12, B9), Paresthesia (B5), and Dermatitis (B7). Symptoms often involve nerve issues, skin problems, and energy metabolism disruptions.
What is the chemical name for Vitamin K and its primary function?
The chemical name for Vitamin K is Phylloquinone (K1) and Menaquinones (K2). Its primary function is vital for blood clotting and bone health.
Which vitamin deficiency is associated with night blindness?
Night blindness is a classic symptom of Vitamin A deficiency. It is a very common question in competitive exams.
Can a vegan diet lead to a specific vitamin deficiency, and if so, which one?
Yes, individuals on a strict vegan diet are at a higher risk of Vitamin B12 deficiency because B12 is primarily found in animal products. Supplementation is often recommended for vegans.
What is the role of Vitamin D in bone health?
Vitamin D is crucial for the absorption of calcium and phosphorus, both essential minerals for building and maintaining strong bones. Its deficiency can lead to Rickets in children and Osteomalacia in adults.