Who is most likely at risk of a vitamin D deficiency?

• A. A 19th century sailor who does not consume much fruit or vegetables on a long voyage at sea.
• B. Brittany, a vegetarian who lives in a sunny beachside town & spends significant time in the sun.
• C. Dave, a vegan who lives in a city that receives very little sunlight.
• D. Maya, who lives in the same city as Dave but eats fish, dairy products, & eggs.

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the role of vitamin D in the body. Vitamin D is essential for calcium absorption, bone health, and immune function. It can be obtained through dietary sources or synthesized in the skin when exposed to sunlight.
2. Step 2: Identify the primary sources of vitamin D. These include sunlight exposure, fortified foods, and animal-based products such as fish, dairy, and eggs. Plant-based sources are limited, making it harder for vegans to meet their vitamin D needs without supplementation.
3. Step 3: Analyze the risk factors for vitamin D deficiency. These include limited sunlight exposure (e.g., living in a city with little sunlight), dietary restrictions (e.g., veganism), and lack of fortified food consumption.
4. Step 4: Evaluate each individual in the problem. The 19th-century sailor is more likely at risk of scurvy (vitamin C deficiency) due to lack of fruits and vegetables. Brittany, despite being vegetarian, gets ample sunlight, reducing her risk. Maya consumes fish, dairy, and eggs, which are good sources of vitamin D, even with limited sunlight. Dave, however, is a vegan and lives in a city with little sunlight, putting him at the highest risk of vitamin D deficiency.
5. Step 5: Conclude that Dave is most likely at risk of vitamin D deficiency due to the combination of limited sunlight exposure and a vegan diet, which lacks natural sources of vitamin D.