Question 1

Which of the following is a water-soluble vitamin that acts as a coenzyme in energy metabolism?

Accepted Answer

Vitamin B1 (thiamine) is a water-soluble vitamin that functions as a coenzyme (thiamine pyrophosphate) in carbohydrate metabolism and energy production. All B vitamins are water-soluble and play crucial roles in energy metabolism.

Question 2

Which of the following diseases is caused by a deficiency of iodine in the diet?

Accepted Answer

Goiter is caused by iodine deficiency. Iodine is essential for the synthesis of thyroid hormones (T3 and T4). When iodine intake is insufficient, the thyroid gland enlarges (becomes a goiter) in an attempt to produce adequate thyroid hormones. Iodine deficiency can also cause hypothyroidism and, in severe cases during pregnancy, cretinism in newborns.

Question 3

Scurvy is a disease caused by the deficiency of which vitamin, and what is its primary function?

Accepted Answer

Scurvy is caused by Vitamin C (ascorbic acid) deficiency. Vitamin C is essential for collagen synthesis, which is required for the structural integrity of blood vessels, skin, and connective tissues. Without adequate Vitamin C, collagen cannot be properly formed, leading to bleeding gums, poor wound healing, and weakened blood vessels.

Question 4

Beriberi is a disease caused by the deficiency of which vitamin?

Accepted Answer

Beriberi is caused by a deficiency of Vitamin B1 (thiamine). This disease was historically common in populations that consumed polished white rice as a staple food, as the thiamine-rich bran was removed during processing.

Question 5

Which of the following vitamins is synthesized by the human body when skin is exposed to sunlight?

Accepted Answer

Vitamin D is synthesized in the skin when exposed to ultraviolet B (UVB) radiation from sunlight. This is why it is often called the 'sunshine vitamin.' The synthesis occurs in the epidermis and dermis layers of the skin.

Question 6

Which of the following vitamins is synthesized by the human body and does NOT need to be obtained primarily from dietary sources?

Accepted Answer

Vitamin D is synthesized by the human body when skin is exposed to ultraviolet (UV) radiation from sunlight. The 7-dehydrocholesterol present in the skin is converted to previtamin D3, which is then converted to active vitamin D (calcitriol) in the liver and kidneys. While dietary sources exist, the body's endogenous synthesis is the primary source for most people. Vitamins A, B12, and C cannot be synthesized by the human body and must be obtained from food sources.

RRB Group D Diseases & Nutrition

Diseases & Nutrition— Rules & Concept

Key Points to Remember

Exam-Specific Tips

Diseases & Nutrition — Practice Questions

60-Second Revision — Diseases & Nutrition