A nutrient lacks sufficient evidence for an RDA but has an AI set. Which inference is most accurate about the certainty and intended use of the AI compared with an RDA?

• A. AI is equivalent to the EAR but uses a different name when nutrients have no known toxicity, and it should be used interchangeably with the RDA in public health surveys.
• B. AI represents a minimum threshold that prevents deficiency in all individuals, while RDA indicates an upper bound beyond which toxicity will occur.
• C. AI is strictly more precise than an RDA because it is derived from a broad consensus rather than statistical modeling, and therefore should always be preferred for clinical prescriptions.
• D. AI is a best-estimate intake assumed to be adequate based on limited evidence or observed intakes, and it carries more uncertainty than an RDA, which is statistically derived to cover ≈97–98% of individual needs.

Answer: (D)