Problem 45 - Arihant Objective Approach to Organic Chemistry for IIT JEE and NEET all Medical Entrances Part 4

Question

Deficiency of vitamin-D causes: (a) night blindness (b) rickets (c) scurvy (d) loss of appetite

Step-by-Step Solution

Answer

Deficiency of vitamin-D causes rickets (option b).

Step 1: Understanding Vitamin-D Deficiency

Vitamin-D deficiency primarily affects bone health and development. The main function of vitamin-D is to promote the absorption of calcium and phosphorus in the body, which are essential for the development of strong and healthy bones.

Step 2: Analyze Each Option

Let's examine each provided option: (a) Night blindness: This is typically associated with vitamin A deficiency, not vitamin D. (b) Rickets: This condition is directly associated with vitamin D deficiency. Rickets leads to softening and weakening of bones in children due to impaired mineralization. (c) Scurvy: This condition is caused by vitamin C deficiency. (d) Loss of appetite: Although it can be a symptom of vitamin D deficiency in severe cases, it is not a primary or common result of it.

Step 3: Identify the Correct Condition

Based on the analysis of the options, rickets is the condition most directly caused by a deficiency in vitamin D. This aligns with the symptoms and function of vitamin D related to bone health.

Key Concepts

Bone Health

Vitamin D plays a vital role in maintaining bone health. This essential nutrient helps regulate calcium and phosphorus in our body, which are critical components in bone formation. Without sufficient vitamin D, the body struggles to maintain bone density and firmness.

Healthy bones are vital for:

• Support and structure: Bones protect internal organs and provide a framework for muscles, enabling movement.
• Mineral storage: Bones store essential minerals, such as calcium, which can be released into the bloodstream as needed.
• Blood cell production: Bone marrow is responsible for producing red and white blood cells, crucial for transporting oxygen and fighting infections.

Understanding the importance of bone health underscores the necessity of adequate vitamin D intake for overall well-being and physical development.

Calcium Absorption

Vitamin D is indispensable for efficient calcium absorption in the intestines. When you intake calcium through food, vitamin D ensures that it gets absorbed into your bloodstream effectively, rather than being excreted.

Reasons why calcium absorption is vital include:

• Building strong bones and teeth: Calcium strengthens bone structures and tooth enamel.
• Muscle function: This mineral facilitates muscle contractions, helping in movement and coordination.
• Nerve transmission: Calcium is crucial for transmitting signals between the brain and other parts of the body.

Without sufficient vitamin D, the body cannot absorb calcium adequately, leading to weakened bones and potential bone disorders like osteoporosis.

Rickets

Rickets is a condition arising from vitamin D deficiency that predominantly affects young children. It leads to the softening and weakening of bones, often resulting in skeletal deformities. This occurs because insufficient vitamin D impairs bone mineralization, a process essential for replacing old bone tissue with new tissue.

Key characteristics of rickets include:

• Bowed legs: Young children with rickets often develop bow-shaped legs due to weakened bones.
• Delayed growth: Affected children may exhibit slower growth patterns and shorter stature.
• Painful bones: Tenderness or pain when moving is common, due to soft bone structures.
• Dental issues: Rickets can lead to poor tooth development and increased risk of cavities.

Preventing rickets involves ensuring adequate vitamin D intake through diet, supplements, and sun exposure, which supports healthy bone development and growth.