A 50-year-old takes a vitamin D supplement of 2,000 IU/day and consumes fortified milk providing 1,200 IU/day. The Institute's UL for vitamin D is 4,000 IU/day. Is the person currently within safe limits, and what would be an appropriate recommendation?

• A. No — because fortified milk counts as negligible, only the supplement counts and 2,000 IU by itself is above the UL for vitamin D so immediate cessation is required.
• B. Yes — any intake below 5,000 IU/day is universally considered optimal and there is no need to monitor additions from other sources.
• C. Yes — total 3,200 IU/day is below the 4,000 IU/day UL; continue current supplementation but avoid adding other high-dose vitamin D products without professional guidance.
• D. No — 3,200 IU/day exceeds safety limits for all adults and the supplement should be stopped immediately with emergency treatment for overdose.

Answer: (C)