Which set of micronutrients correctly lists those with increased RDAs in older adults and correctly pairs them with underlying physiological reasons?

• A. Iron, folate, and vitamin K increase because older adults have higher rates of cell division and need more to sustain rapid growth.
• B. All micronutrient RDAs decrease uniformly after 50 because digestion becomes universally less efficient, requiring less intake across the board.
• C. Vitamin A, potassium, and vitamin C increase due to increased skin breakdown and immune senescence in older adults.
• D. Vitamin D (reduced skin synthesis), calcium (reduced absorption and bone density loss), and vitamin B6 (increased need for metabolic and neurologic processes) — all increase to mitigate osteoporosis and chronic disease risk.

Answer: (D)