Correct Answer: C

Rationale: Fat-soluble vitamins are not stored in the pancreas; they are stored in the liver and fatty tissues. Choice A is correct as fat-soluble vitamins are fairly stable to heat. Choice B is also correct as fat-soluble vitamins contain carbon. Choice D is correct as fat-soluble vitamins are absorbed in the intestine along with fats and lipids in food.

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: 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: B

Rationale: Tocopherol, Choice B, is not a form of vitamin K; it is another name for vitamin E. Phylloquinone (Choice A), menaquinone (Choice C), and menadione (Choice D) are all forms of vitamin K. Phylloquinone is vitamin K1 found in green plants, menaquinone is vitamin K2 produced in the large intestine and found in animal tissues, and menadione is a synthetic form of vitamin K. Therefore, Choice B is the correct answer because it does not belong to the vitamin K group, unlike the other options.

Correct Answer: A

Rationale: The correct answer is A: 'Blood clotting, transmission of nerve impulses, muscle contraction and relaxation.' Calcium plays a crucial role in various physiological functions such as blood clotting, transmission of nerve impulses, muscle contraction and relaxation, membrane permeability, and activation of certain enzymes. Choice B is incorrect because while calcium is involved in calcium homeostasis, it is not the only role it plays in the body. Choice C is incorrect as calcium indeed has several known metabolic functions, and it is not solely for preventing caries. Choice D is also incorrect as the functions mentioned are primarily carried out by other nutrients and not specifically by calcium.