Which of the following foods are a good source of preformed vitamins A (e.g. retinol)?

• A. Liver, milk, eggs.
• B. Carrots, spinach, sweet potatoes.
• C. Kale, spinach, lettuce.
• D. All of the above.

Answer: (A)

Verified step by step guidance

1. Understand the difference between preformed vitamin A and provitamin A: Preformed vitamin A (e.g., retinol) is found in animal-based foods, while provitamin A (e.g., beta-carotene) is found in plant-based foods and must be converted into retinol in the body.
2. Identify the food sources of preformed vitamin A: These are typically animal-derived foods such as liver, milk, and eggs, which contain retinol directly.
3. Recognize that plant-based foods like carrots, spinach, and sweet potatoes are rich in beta-carotene, a provitamin A, not preformed vitamin A.
4. Evaluate the options provided: Determine which options include foods that are sources of preformed vitamin A (animal-based) and which include provitamin A (plant-based).
5. Conclude that the correct answer is the one that includes all relevant sources of vitamin A, both preformed and provitamin A, as the question asks for a comprehensive understanding of vitamin A sources.