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: 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: 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: C

Rationale: The correct answer is C. Maintenance of more than 200 genes is not a function of vitamin A; instead, it is a function of Vitamin D. Vitamin A plays a crucial role in the prevention of night blindness by aiding in the production of the visual pigment rhodopsin. It also supports the growth of soft tissues and bone, as well as the integrity of body openings and their linings. Choice C is incorrect because the maintenance of genes is primarily associated with Vitamin D, not Vitamin A.

Correct Answer: D

Rationale: The correct answer is D: Potassium. Chronic potassium deficiency can lead to hypertension, heart attack, stroke, kidney stones, and osteoporosis. Patients experiencing this deficiency may feel tired, weak, and irritable without knowing the cause. Choice A (Zinc) is incorrect as zinc deficiency presents with different symptoms. Choice B (Iron) deficiency is associated with anemia symptoms, not the conditions listed. Choice C (Sodium) deficiency typically manifests as muscle cramps, weakness, and confusion, not the conditions described in the question.

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: C

Rationale: Multiple exposures of small quantities are considered most cariogenic. The total amount of dietary fermentable carbohydrate seems to matter less than the form and frequency in which it is consumed. Having multiple exposures of even small quantities of fermentable carbohydrate throughout the day promotes a highly cariogenic environment in the mouth. Choices A and B, involving single exposures, are less cariogenic as they do not sustain the fermentation process over time. Choice D suggests a beneficial practice by chewing sugarless gum after exposures, which can reduce the risk, making it less cariogenic compared to multiple exposures of small quantities.

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: The correct answer is B. Water-soluble vitamins do not develop deficiencies rapidly because the body does not store them for long periods. They must be obtained through food constantly. Choice A is correct because water-soluble vitamins often act as coenzymes in various metabolic reactions. Choice C is correct as daily intake of water-soluble vitamins is necessary since they are not stored in the body. Choice D is incorrect as water-soluble vitamins are absorbed primarily in the small intestine, particularly in the duodenum and ileum, not the jejunum.