MCQ on Vitamins

🟢 Easy Level (1–20)

1. Which vitamin is also known as ascorbic acid?
   A) Vitamin A
   B) Vitamin B12
   C) Vitamin C ✅
   D) Vitamin D
   Explanation: Vitamin C is commonly known as ascorbic acid and is essential for immune function and collagen synthesis.
2. Which vitamin is primarily responsible for vision?
   A) Vitamin A ✅
   B) Vitamin D
   C) Vitamin B6
   D) Vitamin E
   Explanation: Vitamin A is essential for the maintenance of vision and eye health.
3. Which vitamin helps in blood clotting?
   A) Vitamin C
   B) Vitamin D
   C) Vitamin K ✅
   D) Vitamin B1
   Explanation: Vitamin K is crucial for the synthesis of clotting factors.
4. Which vitamin is synthesized by sunlight exposure?
   A) Vitamin A
   B) Vitamin D ✅
   C) Vitamin K
   D) Vitamin C
   Explanation: Vitamin D is produced in the skin upon exposure to UVB rays from sunlight.
5. Which vitamin deficiency causes scurvy?
   A) Vitamin B1
   B) Vitamin C ✅
   C) Vitamin A
   D) Vitamin D
   Explanation: Scurvy results from a deficiency of vitamin C, affecting collagen production.
6. Which is a fat-soluble vitamin?
   A) Vitamin C
   B) Vitamin B12
   C) Vitamin D ✅
   D) Vitamin B2
   Explanation: Fat-soluble vitamins include A, D, E, and K.
7. Vitamin B12 is mainly found in:
   A) Fruits
   B) Vegetables
   C) Animal products ✅
   D) Nuts
   Explanation: Vitamin B12 is predominantly found in meat, eggs, and dairy.
8. Beriberi is caused by deficiency of:
   A) Vitamin B6
   B) Vitamin B1 ✅
   C) Vitamin B2
   D) Vitamin C
   Explanation: Thiamine (B1) deficiency leads to beriberi.
9. Which vitamin acts as an antioxidant?
   A) Vitamin K
   B) Vitamin E ✅
   C) Vitamin D
   D) Vitamin B1
   Explanation: Vitamin E protects cells from oxidative damage.
10. Which vitamin is essential for calcium absorption?
    A) Vitamin A
    B) Vitamin C
    C) Vitamin D ✅
    D) Vitamin K
    Explanation: Vitamin D enhances intestinal absorption of calcium.
11. Pellagra is caused by deficiency of:
    A) Vitamin B3 ✅
    B) Vitamin B6
    C) Vitamin B12
    D) Vitamin A
    Explanation: Pellagra results from a deficiency of niacin (B3).
12. Which vitamin is important for red blood cell formation?
    A) Vitamin D
    B) Vitamin B12 ✅
    C) Vitamin K
    D) Vitamin E
    Explanation: B12 is necessary for RBC formation in the bone marrow.
13. Vitamin A deficiency causes:
    A) Night blindness ✅
    B) Rickets
    C) Scurvy
    D) Pellagra
    Explanation: Lack of vitamin A leads to impaired night vision.
14. Which vitamin helps prevent neural tube defects during pregnancy?
    A) Vitamin C
    B) Folic acid ✅
    C) Vitamin D
    D) Vitamin K
    Explanation: Folic acid (B9) is essential in early pregnancy for fetal neural development.
15. Which vitamin helps in energy metabolism?
    A) Vitamin A
    B) Vitamin D
    C) Vitamin B-complex ✅
    D) Vitamin K
    Explanation: B vitamins play a key role in converting food into energy.
16. Which of the following is a water-soluble vitamin?
    A) Vitamin A
    B) Vitamin C ✅
    C) Vitamin D
    D) Vitamin E
    Explanation: Vitamin C and all B-complex vitamins are water-soluble.
17. What does vitamin D prevent?
    A) Scurvy
    B) Rickets ✅
    C) Pellagra
    D) Night blindness
    Explanation: Vitamin D is vital for bone health and prevents rickets.
18. Vitamin E is also known as:
    A) Retinol
    B) Ascorbic acid
    C) Tocopherol ✅
    D) Niacin
    Explanation: Tocopherol is another name for vitamin E.
19. Vitamin B9 is also called:
    A) Niacin
    B) Thiamine
    C) Folic acid ✅
    D) Riboflavin
    Explanation: Vitamin B9 is essential in DNA synthesis and cell growth.
20. Which vitamin is essential for the immune system?
    A) Vitamin K
    B) Vitamin C ✅
    C) Vitamin B1
    D) Vitamin D
    Explanation: Vitamin C boosts immunity and helps fight infections.

🟡 Moderate Level (21–40)

21. Vitamin D deficiency in adults causes:
    A) Rickets
    B) Osteomalacia ✅
    C) Scurvy
    D) Pellagra
    Explanation: Osteomalacia is softening of bones due to low vitamin D.
22. Vitamin B2 is also called:
    A) Riboflavin ✅
    B) Niacin
    C) Pyridoxine
    D) Biotin
    Explanation: Riboflavin (B2) is vital for energy metabolism.
23. Which vitamin deficiency causes bleeding gums?
    A) Vitamin D
    B) Vitamin K
    C) Vitamin C ✅
    D) Vitamin B1
    Explanation: Scurvy from vitamin C deficiency results in gum bleeding.
24. Vitamin B6 is also known as:
    A) Niacin
    B) Biotin
    C) Pyridoxine ✅
    D) Riboflavin
    Explanation: Pyridoxine helps in amino acid metabolism.
25. Which vitamin is destroyed by heat easily?
    A) Vitamin C ✅
    B) Vitamin K
    C) Vitamin D
    D) Vitamin B12
    Explanation: Vitamin C is heat-sensitive and easily destroyed during cooking.
26. Which vitamin is important for DNA synthesis?
    A) Vitamin B9 ✅
    B) Vitamin B2
    C) Vitamin E
    D) Vitamin A
    Explanation: Folic acid plays a major role in DNA synthesis and repair.
27. Excess of which vitamin causes hypervitaminosis?
    A) Vitamin B12
    B) Vitamin C
    C) Vitamin A ✅
    D) Vitamin B1
    Explanation: Fat-soluble vitamins like A can accumulate and become toxic.
28. Which vitamin is also used to treat acne?
    A) Vitamin C
    B) Vitamin A ✅
    C) Vitamin E
    D) Vitamin D
    Explanation: Retinoids (vitamin A derivatives) are used for acne treatment.
29. Which B vitamin is involved in nerve function?
    A) Vitamin B1 ✅
    B) Vitamin B2
    C) Vitamin B5
    D) Vitamin B7
    Explanation: Thiamine supports nerve health and function.
30. Which vitamin is needed to form collagen?
    A) Vitamin K
    B) Vitamin A
    C) Vitamin C ✅
    D) Vitamin D
    Explanation: Vitamin C is crucial for collagen production.
31. Which vitamin deficiency causes megaloblastic anemia?
    A) Vitamin A
    B) Vitamin B12 ✅
    C) Vitamin D
    D) Vitamin E
    Explanation: B12 and folate deficiencies lead to abnormal RBCs.
32. Which vitamin is a coenzyme in carboxylation reactions?
    A) Vitamin K ✅
    B) Vitamin A
    C) Vitamin C
    D) Vitamin B6
    Explanation: Vitamin K is needed for carboxylation of clotting factors.
33. Which vitamin is necessary for the synthesis of neurotransmitters?
    A) Vitamin B6 ✅
    B) Vitamin C
    C) Vitamin A
    D) Vitamin D
    Explanation: Pyridoxine helps in neurotransmitter synthesis.
34. Which vitamin prevents oxidative stress?
    A) Vitamin E ✅
    B) Vitamin A
    C) Vitamin D
    D) Vitamin K
    Explanation: Vitamin E acts as a major antioxidant.
35. Which vitamin is essential for hair and nail health?
    A) Vitamin D
    B) Biotin ✅
    C) Niacin
    D) Riboflavin
    Explanation: Biotin (B7) promotes hair and nail growth.
36. Vitamin A is stored in the:
    A) Kidney
    B) Liver ✅
    C) Brain
    D) Lungs
    Explanation: The liver stores vitamin A in the form of retinyl esters.
37. Which vitamin is found in yellow and orange vegetables?
    A) Vitamin K
    B) Vitamin A (beta-carotene) ✅
    C) Vitamin B12
    D) Vitamin E
    Explanation: Beta-carotene, a precursor of vitamin A, is abundant in colored veggies.
38. Which vitamin is also known as anti-sterility vitamin?
    A) Vitamin A
    B) Vitamin E ✅
    C) Vitamin D
    D) Vitamin K
    Explanation: Vitamin E maintains reproductive health in animals.
39. Which vitamin deficiency can lead to depression?
    A) Vitamin B12 ✅
    B) Vitamin K
    C) Vitamin D
    D) Vitamin A
    Explanation: B12 is linked with neurological and psychological functions.
40. Which vitamin is added to milk to prevent rickets?
    A) Vitamin C
    B) Vitamin D ✅
    C) Vitamin K
    D) Vitamin B2
    Explanation: Fortified milk contains vitamin D to prevent bone diseases.

🔴 Hard Level (41–50)

41. Which vitamin is essential for carnitine synthesis?
    A) Vitamin B12
    B) Vitamin C ✅
    C) Vitamin D
    D) Vitamin E
    Explanation: Vitamin C aids in carnitine synthesis, crucial for energy metabolism.
42. The deficiency of which vitamin is rare but can cause hemorrhagic disease in newborns?
    A) Vitamin D
    B) Vitamin C
    C) Vitamin K ✅
    D) Vitamin A
    Explanation: Newborns may lack vitamin K, affecting clotting.
43. Which vitamin is most likely to cause toxicity symptoms if taken in excess?
    A) Vitamin C
    B) Vitamin D ✅
    C) Vitamin B1
    D) Folic acid
    Explanation: Vitamin D toxicity can lead to hypercalcemia.
44. Biotin is a coenzyme for:
    A) Dehydrogenases
    B) Carboxylases ✅
    C) Decarboxylases
    D) Kinases
    Explanation: Biotin functions as a coenzyme for carboxylation reactions.
45. What is the active form of vitamin D?
    A) Cholecalciferol
    B) Ergocalciferol
    C) Calcitriol ✅
    D) Retinol
    Explanation: Calcitriol is the hormonally active form of vitamin D.
46. Which vitamin helps convert homocysteine to methionine?
    A) Vitamin B6
    B) Vitamin B12 ✅
    C) Vitamin B1
    D) Vitamin C
    Explanation: B12 is required in the remethylation of homocysteine.
47. Which vitamin helps in vision in low light?
    A) Vitamin D
    B) Vitamin A ✅
    C) Vitamin E
    D) Vitamin K
    Explanation: Vitamin A is needed for rhodopsin, a pigment in low-light vision.
48. Which vitamin regulates gene expression?
    A) Vitamin B6
    B) Vitamin D ✅
    C) Vitamin E
    D) Vitamin C
    Explanation: Vitamin D binds to receptors influencing gene transcription.
49. The coenzyme form of vitamin B1 is:
    A) TPP (Thiamine pyrophosphate) ✅
    B) FAD
    C) NAD
    D) FMN
    Explanation: TPP is the active coenzyme form of thiamine.
50. Which vitamin requires intrinsic factor for absorption?
    A) Vitamin C
    B) Vitamin B6
    C) Vitamin B12 ✅
    D) Vitamin K
    Explanation: Vitamin B12 binds intrinsic factor for intestinal absorption.