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: 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.

Correct Answer: B

Rationale: The correct answer is B: Iron. The provided extract mentions that iodine deficiency can cause delayed tooth eruption, enlarged tongue, stillbirths, altered craniofacial growth, sensitivity to cold, dry skin, depression, and goiter. Zinc, Sodium, and Potassium are not associated with these specific symptoms. Zinc deficiency can lead to other health issues but not the ones mentioned. Sodium and Potassium imbalances do not typically result in the symptoms described in the question.

Correct Answer: D

Rationale: The correct answer is D, Aspartame. Aspartame contains phenylalanine, which is contraindicated for individuals with phenylketonuria (PKU), a genetic disorder that impairs phenylalanine metabolism. Therefore, patients with PKU should avoid aspartame. Choices A, B, and C (Cyclamate, Acesulfame-K, Saccharin) are considered safe for individuals with PKU as they do not contain phenylalanine and can be recommended as alternatives to sugar for these patients.

Correct Answer: C

Rationale: The first statement is true; the second is false. Complex carbohydrates are also called polysaccharides and contain more than 10 monosaccharides. Choice A is incorrect because the second statement is false. Choice B is incorrect because the first statement is true. Choice D is incorrect because the second statement is false.

Correct Answer: C

Rationale: Vitamin A can be stored in the liver to meet basic needs for at least 1 year. This storage capacity allows the body to have a reserve of Vitamin A to sustain its needs over an extended period. Choices A, B, and D are incorrect because they underestimate the storage capacity of Vitamin A in the liver, which can last longer than these durations.

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: C

Rationale: The correct answer is C because MyPlate actually provides more specific guidance compared to MyPyramid. MyPlate was designed to simplify the dietary recommendations for consumers by focusing on a visual representation of a plate divided into food groups, making it easier to understand and apply. Choices A, B, and D accurately describe features of MyPlate: replacing MyPyramid, providing personalized dietary guidance through an interactive website, and grouping foods with similar nutrients while emphasizing proportionality of food selections.

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.