"How much is too much?" is a question often asked be clients who are considering taking supplements. Match the supplement with the recommended adult upper level.       Level (A-F) Vitamin or Mineral Recommended Daily Upper Level for Adults 1. Calcium A. 35 milligrams 2. Folate B. 50 micrograms 3. Niacin C. 400 milligrams 4. Vitamin C D. 1,000 micrograms 5. Vitamin D E. 1,000 milligrams 6. Vitamin E F. 2,500 milligrams