Correct Answer: D

Rationale: The correct answer is D. Vitamin K absorption decreases with high levels of vitamin E supplementation because in larger amounts, vitamin E acts as an anticoagulant. Vitamin K is not produced in the gut but can be obtained from food sources or supplements. Vitamin K is essential for the synthesis of blood-clotting factors and is crucial in maintaining prothrombin levels, which is vital for proper blood clotting. The incorrect choice, D, is misleading as high levels of vitamin E supplementation hinder vitamin K absorption due to its anticoagulant properties. Dental hygienists should be aware of the importance of vitamin K in blood clotting, especially when treating patients who are on anticoagulant medications for conditions like stroke prevention.

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: A

Rationale: The correct answer is A: Elderly. The other choices provided, low income, vegans, and chronic disease, alcoholics, are also at risk for nutritional deficiencies but the question specifically asks for 4 groups out of the 12 discussed. The 12 groups at risk for nutritional deficiencies include the elderly, low income individuals, vegans, chronic disease, alcoholics, smokers, periods of growth, individuals with medical conditions, physical stress, physiological stress, those on polypharmacy, and those with inadequate intake. The question focuses on identifying 4 out of these 12 groups, making 'Elderly' the correct choice.

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 statements are true. Systemic diseases can often present with oral manifestations before other systemic signs appear. Additionally, oral diseases can have systemic implications by affecting a person's overall health, such as through inflammation or compromised nutrient intake. Choice B is incorrect because both statements are true, as supported by medical literature. Choice C is incorrect because the second statement is also true. Choice D is incorrect because the first statement is true.