Which of the following statements are true about iron?

Correct Answer: C

Rationale: Choice C is correct because iron absorption is indeed increased by Vitamin C and during pregnancy. The other choices are incorrect. Choice A is wrong as there are no universally accepted percentages for the iron needs of vegans and endurance athletes. Choice B is inaccurate as iron deficiency is actually one of the most common nutritional deficiencies worldwide. Choice D is incorrect because tannic acid and calcium in milk actually inhibit iron absorption rather than increasing it.

Correct Answer: B

Rationale: The statement that the major function of vitamin E is promoting vision is incorrect. Vitamin E primarily acts as an antioxidant, protecting cells from oxidative damage. Its role is not primarily related to vision, which is a major function of vitamin A. On the other hand, the other options are true. Vitamin K deficiency does indeed lead to increased clotting time, vitamin D functions as a hormone, and carrots, sweet potatoes, and butternut squash are rich sources of beta-carotene.

Correct Answer: A

Rationale: The statement is true. Both males and females are at risk of developing osteoporosis if they do not consume enough calcium. Calcium is essential for maintaining strong bones, and inadequate intake can lead to bone density loss and increase the risk of osteoporosis. Therefore, it is crucial for individuals of all genders to ensure they have an adequate calcium intake to support bone health. Choice B is incorrect because osteoporosis is a condition that can affect both males and females.

Correct Answer: D

Rationale: The primary purpose of dietary fiber in the diet is to reduce cholesterol levels. While it does aid in digestion by promoting regular bowel movements, its main role is in lowering cholesterol. Choice A is partially correct but not the primary purpose. Choice B is incorrect as fiber is not a direct source of energy. Choice C is also incorrect as the primary role of fiber is not in the absorption of vitamins.

Correct Answer: C

Rationale: Vitamin K is essential for blood clotting as it plays a crucial role in the activation of clotting factors. Deficiency of Vitamin K can lead to impaired blood clotting, resulting in bleeding disorders. Vitamin A is more associated with vision and skin health, not blood clotting. Vitamin E is known for its antioxidant properties and role in immune function, not specifically related to bleeding disorders. Vitamin D plays a key role in calcium absorption and bone health, but it is not directly linked to blood clotting or bleeding disorders.