Intrinsic factor from the stomach is needed for the absorption of which vitamin?

Correct Answer: A

Rationale: The correct answer is A: vitamin B12. Intrinsic factor is a glycoprotein produced by the stomach that is necessary for the absorption of vitamin B12 in the small intestine. Vitamin B12 binds to intrinsic factor in the stomach, forming a complex that is then absorbed in the ileum. This absorption process is crucial for preventing vitamin B12 deficiency. Choices B, C, and D are incorrect because they do not require intrinsic factor for absorption. Folate is absorbed in the small intestine through a different mechanism, niacin can be absorbed in the small intestine without the need for intrinsic factor, and vitamin B6 does not rely on intrinsic factor for absorption.

Correct Answer: C

Rationale: The correct answer is vitamin E. Vitamin E is the major antioxidant found in cell membranes, where it plays a crucial role in protecting them from oxidative damage. Although B12, beta-carotene, and vitamin A are important nutrients with specific functions in the body, they are not the primary antioxidants found in cell membranes. Vitamin E specifically localizes in cell membranes to neutralize free radicals and prevent lipid peroxidation, making it an essential antioxidant for cellular health.

Correct Answer: A

Rationale: Salmon is the correct answer as it is a rich source of omega-3 fatty acids, specifically EPA and DHA, which are known to be beneficial for heart health. Chicken, spinach, and eggs do not contain significant levels of omega-3 fatty acids compared to salmon. While eggs do contain some omega-3s, the amount is considerably lower than what is found in fatty fish like salmon.

Correct Answer: B

Rationale: The correct answer is B: Avoid gluten. Patients with celiac disease have an immune reaction to gluten, a protein found in wheat, barley, and rye. Therefore, it is crucial for individuals with celiac disease to avoid gluten-containing products. Increasing protein intake (Choice A) is not specifically necessary for celiac disease management. Increasing dairy intake (Choice C) is unrelated to the dietary requirements of individuals with celiac disease. Avoiding lactose (Choice D) is relevant for individuals with lactose intolerance, not celiac disease. Therefore, the only necessary modification for a patient with celiac disease is to avoid gluten.

Correct Answer: C

Rationale: The correct answer is Vitamin D. Vitamin D is synthesized in the skin when it is exposed to sunlight. This process allows the body to produce Vitamin D naturally. Vitamin A (Choice A) is found in foods like liver and carrots and is not primarily obtained from sunlight. Vitamin C (Choice B) is commonly found in fruits and vegetables. Vitamin E (Choice D) is present in foods like nuts and seeds and is not primarily obtained from sunlight.