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)
Role: Essential for maintaining good vision, boosting immunity, and promoting healthy skin.
Sources:
- Carrots
- Sweet potatoes
- Spinach
- Liver
- Eggs
Deficiency Causes:
- Poor intake of animal products and vegetables
- Chronic malnutrition
Deficiency Disease:
- Night Blindness: Inability to see in low light or at night and weakened immunity
- Xerophthalmia: Dryness of the eyes, which can lead to blindness.
Exam Tip: Vitamin A deficiency causes night blindness, a frequent competitive exam question.
2. Vitamin B1 (Thiamine)
Role: Helps convert carbohydrates into energy, crucial for the nervous system.
Sources:
- Whole grains
- Pork
- Legumes
- Nuts
- Black beans
Deficiency Causes:
- High alcohol consumption
- Diets low in whole grains
Deficiency Disease:
- Beriberi: Causes weakness, nerve damage, and cardiovascular issues (heart disorders).
- Wernicke-Korsakoff Syndrome: Neurological disorder, often related to alcoholism.
Exam Tip: Questions often appear about beriberi caused by a deficiency in vitamin B1.
3. Vitamin B2 (Riboflavin)
Role: Important for energy production and the health of skin and eyes.
Sources:
- Milk and dairy
- Eggs
- Almonds
- Leafy greens
- Whole grains
Deficiency Causes:
- Low dairy intake
- Poor absorption in the digestive system
Deficiency Disease:
- Ariboflavinosis: Symptoms include skin disorders, cracked lips, mouth and throat inflammation and sore throat, itchy and red eyes a swollen tongue.
Exam Tip: Riboflavin deficiency, also known as ariboflavinosis, can cause cheilosis.
4. Vitamin B3 (Niacin)
Role: Supports skin health, nerve function, and metabolism.
Sources:
- Poultry
- Fish
- Peanuts
- Whole grains
Deficiency Causes:
- Lack of niacin or tryptophan in the diet
- Chronic alcoholism
Deficiency Disease:
- Pellagra: Characterised by dermatitis, diarrhea, and dementia.
Exam Tip: Competitive exams often ask about pellagra, a result of vitamin B3 deficiency.
5. Vitamin B5 (Pantothenic Acid)
Role: Necessary for synthesising coenzymes for energy metabolism.
Sources:
- Avocados
- Chicken
- Mushrooms
- Broccoli
Deficiency Causes:
- Rare, but possible with severe malnutrition
- Symptoms include fatigue, irritability, and muscle cramps
Deficiency Disease:
- Fatigue, irritability, and muscle cramps: Although rare, these are symptoms linked to B5 deficiency.
Exam Tip: Vitamin B5 is also known as Pantothenic Acid
6. Vitamin B6 (Pyridoxine)
Role: Vital for brain development and function, especially for producing neurotransmitters.
Sources:
- Bananas
- Chickpeas
- Fish (salmon)
- Potatoes
Deficiency Causes:
- Alcoholism
- Certain medications (e.g., tuberculosis treatments)
Deficiency Disease:
- Anemia: Reduced production of hemoglobin, leading to tiredness and weakness.
- Depression and Confusion: Due to its role in neurotransmitter production.
Exam Tip:
- Vitamin B6 is water soluble whose deficiency causes convulsions disease.
- Vitamin B6 (Pyridoxine) is given with isoniazid (INH) because it provides the vitamin when isoniazid with natural vitamin synthesis.
7. Vitamin B7 (Biotin)
Role: Essential for healthy hair, skin, and nails, and for converting food into energy.
Sources:
- Eggs
- Almonds
- Soybeans
- Whole grains
Deficiency Causes:
- Consuming raw egg whites for prolonged periods
- Rare genetic conditions
Deficiency Disease:
- Hair Loss and Skin Rashes: Common signs of biotin deficiency.
Exam Tip: Biotin is the chemical name of Vitamin B7
8. Vitamin B9 (Folate/Folic Acid)
Role: Important for DNA synthesis and proper cell division.
Sources:
- Leafy greens
- Beans and legumes
- Citrus fruits
- Fortified cereals
Deficiency Causes:
- Insufficient intake during pregnancy
- Poor absorption due to gastrointestinal disorders
Deficiency Disease:
- Megaloblastic Anemia: Large, abnormal red blood cells leading to fatigue.
- Neural Tube Defects: Inadequate folate during pregnancy can result in birth defects like spina bifida.
Exam Tip: Questions about folic acid supplementation during pregnancy are common in exams.
9. Vitamin B12 (Cobalamin)
Role: Crucial for nerve health and red blood cell production.
Sources:
- Meat
- Dairy
- Fish
- Fortified cereals
Deficiency Causes:
- Vegan diets lacking supplementation
- Pernicious anemia (inability to absorb B12)
Deficiency Disease:
- Pernicious Anemia: Leads to fatigue, weakness, and neurological problems.
- Nerve Damage: Can cause tingling, numbness, and memory loss.
Exam Tip: B12 deficiency is a key topic in exams, often related to vegan diets.
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10. Vitamin C (Ascorbic Acid)
Role: Supports the immune system and is necessary for collagen production.
Sources:
- Oranges
- Strawberries
- Broccoli
- Bell peppers
Deficiency Causes:
- Lack of fresh fruits and vegetables
- Smoking increases the need for vitamin C
Deficiency Disease:
- Scurvy: Symptoms include bleeding gums, fatigue, and poor wound healing.
Exam Tip: Scurvy due to vitamin C deficiency is frequently tested in competitive exams.
11. Vitamin D
Role: Essential for calcium absorption, promoting healthy bones.
Sources:
- Sunlight
- Fatty fish
- Fortified milk
- Egg yolks
Deficiency Causes:
- Lack of sun exposure
- Darker skin or living in northern latitudes
Deficiency Disease:
- Rickets (Children): Leads to soft and weak bones, causing deformities.
- Osteomalacia (Adults): Softening of the bones, resulting in pain and fractures.
Exam Tip:
- Rickets is a well-known topic related to vitamin D deficiency.
- Osteomalacia disease is caused by deficiency of Vitamin D.
12. Vitamin E
Role: Acts as an antioxidant, protecting cells from oxidative damage.
Sources:
- Nuts and seeds
- Sunflower oil
- Spinach
- Almonds
Deficiency Causes:
- Fat malabsorption
- Genetic disorders
Deficiency Disease:
- Muscle Weakness: Due to oxidative damage to muscles.
- Vision Problems: Deficiency can lead to retinopathy, affecting the eyes.
Exam Tip: Deficiency of Vitamin E causes Male Infertility.
13. Vitamin K
Role: Vital for blood clotting and bone health.
Sources:
- Leafy greens (kale, spinach)
- Broccoli
- Soybeans
- Cabbage
- Fortified dairy products
Deficiency Causes:
- Long-term antibiotic use
- Malabsorption issues
Deficiency Disease:
- Excessive Bleeding: Due to impaired blood clotting.
- Bone Weakness: Associated with reduced bone density and fractures.
Exam Tip: Vitamin K is known as the Antihemorrhagic vitamin
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!
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.
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.