Each is a physiologic role of vitamin D, except one. Which is the exception?

Correct Answer: A

Rationale: The correct answer is A, Hematopoiesis. Vitamin D plays a crucial role in regulating serum calcium levels, which is essential for maintaining cardiac and neuromuscular function. Additionally, vitamin D is involved in modulating immune responses. However, hematopoiesis, the formation of red blood cells, is not a direct physiologic role of vitamin D. Therefore, hematopoiesis is the exception among the listed functions of vitamin D.

Correct Answer: A

Rationale: The correct answer is A, Beans. Beans are known to be a good source of protein compared to the other options provided. While red peppers, asparagus, and celery are nutritious vegetables, they do not contain as much protein as beans do. Red peppers are high in vitamin C, asparagus is rich in vitamins and minerals, and celery is low in calories and a good source of fiber, but they are not significant sources of protein.

Correct Answer: D

Rationale: Iron, fiber, and B vitamins are most likely to become insufficient when carbohydrates are eliminated from the diet to lose weight. Carbohydrates are a primary source of B vitamins and fiber in the diet. Iron can also be obtained from plant-based sources like legumes and whole grains, which are often eliminated when carbohydrates are restricted. Choices A, B, and C are incorrect because protein, vitamin K, vitamin A, and vitamin C are not primarily sourced from carbohydrates and are less likely to become insufficient solely due to carbohydrate elimination.

Correct Answer: D

Rationale: The first statement is false because increasing the variety of foods actually helps prevent nutrient excesses and toxicities. The second statement is true because making a dietary change to eliminate or increase the intake of a specific food or nutrient often leads to alterations in the intake of other nutrients. Choice A is incorrect because the first statement is false. Choice B is incorrect because the second statement is true. Choice C is incorrect because the first statement is false, even though the second statement is true.

Correct Answer: D

Rationale: The oral cavity is indeed the site of various systemic disease manifestations due to multiple factors. Firstly, the rapid cellular turnover in the oral mucosa makes it susceptible to diseases. Secondly, the constant presence of microorganisms in the oral cavity contributes to the development of systemic diseases. Finally, the oral cavity being a trauma-intense environment further increases the risk of systemic manifestations. Therefore, all the provided options - rapid cellular turnover, constant attack by microorganisms, and a trauma-intense environment - play a role in making the oral cavity a site for various systemic diseases. Hence, the correct answer is 'All of the above.' Choices A, B, and C are incorrect individually as they each represent only one aspect of why the oral cavity is prone to systemic disease manifestations, whereas the correct answer encompasses all these factors.

Correct Answer: C

Rationale: Vitamin C plays a crucial role in protecting the integrity of cellular membranes. It is essential for collagen synthesis, which is important for wound healing and maintaining skin, blood vessels, and other tissues. Choice A is incorrect as the transcription of DNA to RNA is facilitated by vitamin A. Choice B is incorrect as calcium absorption and regulation are functions of vitamin D. Choice D is incorrect as vitamin K serves as a catalyst for the synthesis of blood-clotting factors, not vitamin C.

Correct Answer: C

Rationale: The correct answer is C. DRIs do not specifically address individuals with disease states; they are intended for the general healthy population. Choice A is correct because DRIs indeed replace the older recommended daily allowances. Choice B is correct as current DRIs aim to estimate required nutrients to enhance long-term health. Choice D is accurate as DRIs also attempt to establish maximum safe levels of tolerance for nutrients.

Correct Answer: A

Rationale: Both the statement and the reason are correct and related. Inadequate intake of vitamin A in lower socioeconomic groups is due to a lack of resources to purchase and consume vegetables and fruits. This is supported by the fact that the average intake in the United States meets the Recommended Dietary Allowance (RDA) for vitamin A intake, except in lower socioeconomic groups. These individuals often lack the financial means to buy, prepare, and eat a variety of fruits and vegetables, leading to deficiencies. It's important to note that because vitamin A can be stored in the liver, most adults have sufficient quantities to maintain health. Choices B, C, and D are incorrect because the statement and reason are both accurate and logically connected, as the lack of resources directly impacts the ability to obtain necessary sources of vitamin A.

Correct Answer: A

Rationale: Both statements are true. The effect of vitamin A on the growth of soft tissues and bones naturally extends to the teeth and surrounding structures. Enamel hypoplasia, involving defective enamel matrix and incomplete calcification of enamel and dentin, can be due to vitamin A deficiency. The effect of this vitamin upon surrounding bone directly affects spacing patterns of the teeth within the bone and dentition. Choice A is correct because both statements accurately describe the influence of vitamin A on tooth development. Choices B, C, and D are incorrect as they do not reflect the accuracy of the statements provided.