Luca has decided to start a vegan diet, excluding all animal-based products. He should:

• A. Not worry about his cholesterol intake because his body can synthesize it naturally.
• B. Take cholesterol supplements so that he has enough in his diet.
• C. Take vitamin D & testosterone supplements because cholesterol is a precursor to the molecules.
• D. Ensure he eats enough cholesterol from plant-based products.

Answer: (A)

Verified step by step guidance

1. Understand the role of cholesterol in the body: Cholesterol is a lipid molecule that is essential for the synthesis of hormones (like testosterone and estrogen), vitamin D, and bile acids. However, the human body can synthesize cholesterol naturally in the liver, so dietary cholesterol is not strictly necessary.
2. Recognize that a vegan diet excludes all animal-based products, which are the primary dietary sources of cholesterol. Plant-based foods do not contain cholesterol, as cholesterol is only found in animal-derived products.
3. Clarify that the body’s ability to synthesize cholesterol ensures that even on a vegan diet, Luca does not need to consume cholesterol from external sources or take cholesterol supplements. The liver produces sufficient cholesterol to meet the body's needs.
4. Address the misconception about plant-based cholesterol: Plants do not contain cholesterol, but they do contain phytosterols, which are structurally similar to cholesterol but do not serve the same biological functions in humans.
5. Conclude that Luca does not need to take cholesterol supplements or worry about cholesterol intake on a vegan diet. However, he should ensure adequate intake of nutrients like vitamin D (which can be synthesized with sunlight exposure or supplemented) and vitamin B12, which is not naturally present in plant-based foods.