Which statement best describes RDA and UL for vitamin A?

• A. RDA provides daily intake sufficient for most individuals; UL is the maximum daily intake unlikely to cause toxicity; excessive vitamin A can cause toxicity, especially from supplements or liver.
• B. UL is the daily requirement for most individuals
• C. RDA is the maximum daily intake
• D. Vitamin A toxicity is impossible with supplements

Answer: (D)

The main idea is understanding what RDA and UL mean for vitamin A. The RDA is the daily amount that will meet the needs of most healthy people and help prevent deficiency, while the UL is the upper limit unlikely to cause adverse effects; amounts above the UL raise the risk of toxicity. For vitamin A, toxicity is a real concern with too much preformed vitamin A, especially from supplements or high liver intake, though beta-carotene from plant sources is less likely to cause this toxicity because the body controls its conversion to vitamin A. So the best statement is that the RDA provides daily intake sufficient for most individuals; UL is the maximum daily intake unlikely to cause toxicity; excessive vitamin A can cause toxicity, especially from supplements or liver. The other options mix up the roles—UL is not the daily requirement, RDA is not the maximum, and toxicity can occur with supplements.