The correct option is (d).
Explanation
Vitamin A is a fat-soluble vitamin critical for maintaining healthy vision, immune function, and cell growth. In the diet, it exists in two primary forms: Preformed Vitamin A (Retinol), found in animal products, and Provitamin A Carotenoids (such as beta-carotene), found in plant-based foods, which the body converts into Vitamin A.
Analysis of Food Items:
- 1. Raw carrots: Correct. Carrots are a rich source of beta-carotene, a provitamin A carotenoid. The body converts beta-carotene into retinol, which is essential for the formation of rhodopsin, a pigment in the retina necessary for low-light vision.
- 2. Spinach: Correct. Dark green leafy vegetables like spinach contain high levels of beta-carotene and other carotenoids (lutein and zeaxanthin), which are beneficial for eye health and serve as a source of Vitamin A.
- 3. Cod liver oil: Correct. This is one of the most concentrated sources of preformed Vitamin A (retinol) and Vitamin D. It is derived from the liver of cod fish and has been historically used to treat Vitamin A deficiency.
- 4. Eggs: Correct. Egg yolks are a significant source of preformed Vitamin A (retinol), along with other nutrients like lutein and zeaxanthin that support eye health.
Key Takeaway:
Vitamin A is obtained from both animal sources (as Retinol in liver, eggs, dairy) and plant sources (as Carotenoids in carrots, spinach, pumpkin). Both forms are essential for preventing night blindness and maintaining corneal health.