Correct Answer: C

Rationale: The correct answer is C. DRIs are intended for the general population and do not specifically address disease states, which are managed with different clinical guidelines. Choice A is correct as DRIs have replaced the older recommended daily allowances. Choice B is correct as current DRIs aim to estimate the required nutrients for long-term health. Choice D is correct as DRIs also attempt to establish maximum safe levels of tolerance for nutrients.

Correct Answer: B

Rationale: Coenzyme Q10 is often recommended for patients on statins because it may help reduce muscle pain, a common side effect of these medications. Iron (Choice A) is not typically recommended for patients taking statins to lower cholesterol. Calcium (Choice C) and Magnesium (Choice D) are not specifically indicated for addressing muscle pain associated with statin use, making them less suitable choices in this scenario.

Correct Answer: B

Rationale: The correct term for diseases of the heart and blood vessels is cardiovascular disease. While coronary artery disease (Choice A) specifically involves the narrowing of coronary arteries, it is just one type of cardiovascular disease. Coronary heart disease (Choice C) is also a specific condition related to the heart's blood vessels. Choice D, coronary vessel disease, is not a commonly used term to describe diseases of the heart and blood vessels. Therefore, Choice B, cardiovascular disease, is the most inclusive and appropriate term to refer to these conditions.

Correct Answer: B

Rationale: Muscle weakness is a common sign of vitamin D deficiency. Vitamin D is essential for calcium absorption and bone health, and its deficiency can lead to muscle weakness. Brittle nails (Choice A) are not typically associated with vitamin D deficiency. Night blindness (Choice C) is related to vitamin A deficiency, not vitamin D deficiency. Hair loss (Choice D) can be linked to various factors, but it is not a common sign of vitamin D deficiency.

Correct Answer: A

Rationale: The correct answer is A: Iron. Iron is an essential nutrient needed by the body to make hemoglobin, the protein in red blood cells that carries oxygen. While other nutrients like vitamin B12, niacin, and folate are important for various bodily functions, they are not directly involved in the production of hemoglobin. Vitamin B12 is essential for nerve function and DNA synthesis, niacin is important for metabolism, and folate is crucial for cell division and DNA synthesis. Therefore, only iron is specifically required for hemoglobin production.