Studies suggest that leukoplakia is resolved by excess vitamin A (a fat-soluble vitamin), retinoids, and beta-carotene. Leukoplakia is a white plaque that forms on oral mucous membranes.

Correct Answer: B

Rationale: Both statements are false. Studies suggest that leukoplakia, a white plaque that forms on oral mucous membranes, can be resolved by vitamin A, retinoids, and beta-carotene. Despite the potential to resolve leukoplakia, relapse is common. Also pertinent, evidence does not indicate that any of these nutrients prevent malignant transformation. The extract provided clarifies that leukoplakia is a white plaque, not an erythematous lesion, and that vitamin A, retinoids, and beta-carotene can help resolve it.

Correct Answer: B

Rationale: A deficiency in iron can lead to various symptoms, such as microcytic anemia, fatigue, faulty digestion, blue sclerae, pale conjunctivae, and tachycardia. Iron-deficiency anemia may be caused by inadequate dietary intake; accelerated demand or losses; and inadequate absorption secondary to diarrhea, decreased acid secretions, or antacid therapy. Iron deficiency is frequently the result of postnatal feeding practices and has a serious impact on growth and mental and psychomotor development in infants and children. Choices A, C, and D are incorrect as zinc deficiency typically presents with symptoms like impaired wound healing, taste abnormalities, and hair loss; sodium deficiency can lead to symptoms such as muscle cramps, dizziness, and confusion; and potassium deficiency may cause muscle weakness, fatigue, and abnormal heart rhythms.

Correct Answer: D

Rationale: Total kilocalories have the greatest effect on body weight as they represent the overall energy intake from all macronutrients combined. While the consumption of specific macronutrients like carbohydrates, proteins, and fats can affect weight management, the total calories consumed play the most significant role in determining body weight. Therefore, choices A, B, and C are incorrect as they focus on individual macronutrients rather than the overall energy balance provided by total kilocalories.

Correct Answer: D

Rationale: The correct answer is D. Phosphorus plays a crucial role in ATP energy release, the metabolism of fats, carbohydrates, and proteins, and regulation of acid-base balance. Choices A, B, and C are incorrect. Phosphorus is not directly involved in blood clotting, transmission of nerve impulses, muscle contraction, or calcium homeostasis. It also has known metabolic functions and is not associated with caries prevention.

Correct Answer: C

Rationale: The statement is correct, but the reason is not correct. A major difference between fat-soluble and water-soluble vitamins is that the body is able to store larger amounts of fat-soluble vitamins. Vitamins A and D are stored for long periods; therefore, minor shortages might not be identified until drastic depletion has occurred. Observable signs and symptoms of a dietary deficiency are often not identified until they are in an advanced state. Water-soluble vitamins, on the other hand, are not stored in the body and are excreted in the urine if taken in excess, making it harder to reach toxic levels.

Correct Answer: D

Rationale: The correct answer is D, Triglycerides. Triglycerides are a type of fat, not a carbohydrate. Monosaccharides, disaccharides, and polysaccharides are all classifications of carbohydrates based on the number of sugar units they contain. Monosaccharides are the simplest form with one sugar unit, disaccharides contain two sugar units, and polysaccharides have multiple sugar units linked together.

Correct Answer: B

Rationale: Both statements are false. While Healthy People (HP 2020) has contributed to a reduction in deaths from cardiovascular disease, stroke, and some cancers, it did not result in decreased dental caries in children aged 2 to 4 years and adults aged 53 to 44 years. Therefore, the correct answer is B. Choice A is incorrect because the second statement is false. Choice C is incorrect as the first statement is also false. Choice D is incorrect as the second statement is false.

Correct Answer: C

Rationale: Scurvy is caused by a deficiency of vitamin C, not vitamin E. The symptoms of scurvy include spontaneous gingival hemorrhaging, perifollicular petechiae, follicular hyperkeratosis, diarrhea, fatigue, depression, and cessation of bone growth. Vitamin A (Choice A) is important for vision and immune function, Vitamin D (Choice B) is essential for bone health, and Vitamin K (Choice D) is necessary for blood clotting. However, none of these vitamins are associated with scurvy.

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.