Chapter 16 — Exercises

C1 (empty the cupboard) and C7 (write the list) are the two that matter. The second one takes four minutes and has occasionally enormous expected value.

Difficulty legend: ⭐ basic recall · ⭐⭐ applied · ⭐⭐⭐ synthesis and judgment · ⭐⭐⭐⭐ extension

Selected answers in Appendix J. Full supplement evidence grades in Appendix H.

Part A — Conceptual Understanding ⭐

A1. What is DSHEA 1994, and what four things does it change relative to drug regulation?

A2. Explain the difference between a disease claim and a structure/function claim. Why does the vocabulary on labels look the way it does?

A3. Describe the two pipelines from §16.1's diagram. Which direction does the burden of proof run in each?

A4. Name the three product categories most commonly found adulterated with undeclared pharmaceuticals, and give an example drug for each.

A5. Name four third-party certification programmes. What do they verify — and what don't they?

A6. List every ✅ and 🟢 supplement in this book, with the chapter each came from.

A7. What do all six nutritional ✅ verdicts have in common? Which two ✅/🟢 verdicts are the exception, and why?

A8. Explain the creatine phosphate mechanism. Why does creatine help a lifter and not a marathoner?

A9. What is a proprietary blend, what is "fairy dusting," and why does the chapter say to treat unassessable as unsupported?

A10. Give six items from the dangerous list, with the harm for each.

A11. Why is St John's Wort described as the most dangerous common supplement interaction?

A12. Explain biotin's interference with troponin assays. In which direction does the error run in sandwich assays, and why is that the dangerous direction?

A13. Why does creatine raise serum creatinine, and why isn't that kidney damage?

Part B — Applied Analysis ⭐⭐

B1. A label reads: "Proprietary Energy Matrix, 650 mg: green tea extract, caffeine anhydrous, L-carnitine, chromium, bitter orange." Identify every problem, including two safety concerns.

B2. Walt's troponin came back low and it was wrong. Walk through the mechanism, and say what would have happened if the junior doctor hadn't read the label.

B3. A 24-year-old competitive swimmer wants to take creatine. What do you tell her about dose, form, cost, and — critically — what must she check before buying?

B4. Someone on warfarin starts taking fish oil, vitamin E, and ginkgo for "circulation." What's the concern, and what would you do?

B5. A woman taking oral contraceptives begins St John's Wort for low mood. Explain the interaction and its consequence. Whose responsibility was it to catch this?

B6. Compare creatine ($0.15/day, hundreds of trials) with a testosterone booster ($55/month, no credible evidence). Using §16.9's six questions, show how the framework distinguishes them.

B7. Someone says "I'd rather take it just in case — it can't hurt." Give three specific counterexamples from this chapter.

B8. A patient is scheduled for a thyroid function test and takes a "hair, skin and nails" supplement. What do you advise, and how far in advance?

Part C — Skills & Practice ⭐⭐–⭐⭐⭐

C1. Empty the cupboard. The Project Checkpoint. Every bottle on the table, one row each: claim · verdict · dose vs UL · monthly cost · annual cost · keep or cut.

C2. Run the three safety checks. ⚠️ Biotin in anything? Zinc total across all products versus the ~40 mg UL? Any proprietary blends?

C3. Total the annual spend. Then compare it to §16.12's table — and to whatever Chapters 8, 11, 13 or 14 identified as your actual gap.

C4. Read five labels properly. For each: the Supplement Facts panel, doses versus UL, proprietary blends, certification marks, the claim's verb, and the disclaimer. Then score each against §16.9's six questions.

C5. Check the tainted products database. Search the FDA's database for any category you've bought from. Note what turns up.

C6. Price creatine. Find third-party certified creatine monohydrate. Calculate cost per day at 3–5 g. Compare to the most expensive thing in your cupboard.

C7. ⚠️ Write the list. Every supplement and medication, with doses, in your phone — under Medications, or in your medical ID, or on a card in your wallet. Then tell one other person it exists. (Four minutes. This is the exercise.)

C8. Ask a pharmacist. Take the list to a pharmacy and ask for an interaction review. In most systems this is free and takes ten minutes.

Part D — Synthesis & Critical Thinking ⭐⭐⭐

D1. DSHEA reversed the burden of proof, meaning safety data is generated by consumers. Construct the strongest case for that framework — access, cost, autonomy, innovation. Then say what you'd change and what it would cost.

D2. Do §16.10's exercise properly: design a supplement that would earn a ✅. Then take the three most expensive products in your cupboard and score them against your own criteria.

D3. Creatine has hundreds of trials and costs $0.15/day; it sits on a shelf beside products costing thirty times more with none. Why hasn't the market corrected? What does that tell you about how supplement purchasing decisions are actually made?

D4. The chapter says "unassessable = unsupported." Is that fair? A proprietary blend might contain effective doses. Argue against the heuristic, then defend it.

D5. Walt's outcome depended on a junior doctor reading a label at 4:30 a.m. Design a system change that wouldn't. Consider: pharmacy records, mandatory disclosure, assay redesign, labelling. What would each cost and who would resist it?

Part M — Mixed & Interleaved Practice ⭐⭐–⭐⭐⭐

M1. (With Chapters 13–15.) List every ✅ verdict in Part III. What single sentence describes what they all have in common?

M2. (With Chapter 13.) Walt's multivitamin "masked" his B12 deficiency. Explain the mechanism and connect it to Chapter 13's threshold concept.

M3. (With Chapter 14.) Walt's immune blend contained two independent hazards. Name both, and say why neither appeared on any medical record.

M4. (With Chapter 6.) Explain creatine's mechanism using Chapter 6's ATP and fuel-store material. Then explain why it does nothing for Devi.

M5. (With Chapters 5, 8 and 11.) Compare the marketing structure of the metabolism aisle, the protein aisle, the fiber aisle, and the supplement aisle. State the general rule in one sentence.

M6. (With Chapter 2.) "Clinically studied ingredient" — run this phrase through the Claim Filter. Which of the six questions does it fail hardest?

M7. (With Chapter 11.) Walt's berberine got 🟡 and his fiber gap got 🟢. Compare the evidence, cost, breadth of effect, and risk. Why did "comparison beat debunking"?

M8. (With Chapter 1.) Apply Chapter 1's six myth shapes to the supplement aisle. Which shapes appear most often, and on which products?

Part E — Research & Extension ⭐⭐⭐⭐

E1. Read DSHEA 1994 itself, or a good legal summary. What problem was it solving? Who lobbied for it and why? Then read a critique of it. Is there a version that preserves access and fixes the evidence gap?

E2. Explore the FDA tainted products database. Categorize the findings by product type and drug class. Then estimate — and state your reasoning — what fraction of the market this represents.

E3. Read the ISSN position stand on creatine. What does it claim, at what evidence level, and what does it explicitly decline to claim? Then find the emerging cognitive literature and assess how much weaker it is.

E4. Read the FDA safety communications on biotin interference (2017, 2019) and the clinical literature on affected assays. Which assay formats are affected and in which direction? Then find out whether your local laboratory's troponin assay is biotin-sensitive — most people cannot, which is itself the finding.

E5. Investigate NIH LiverTox (livertox.nih.gov) for green tea extract, garcinia, kava, and ashwagandha. How many cases, how severe, and how were they identified? This is where post-market surveillance actually happens.

E6. Research St John's Wort and CYP3A4 induction — the mechanism, the affected drug classes, and documented cases of contraceptive failure and transplant rejection. Then consider why a pharmacy-shelf product with this interaction profile requires no warning at point of sale.

E7. Compare supplement regulation across jurisdictions — US (DSHEA), EU (permitted health claims register), Australia (TGA listed medicines), Canada (NHPD). Which does best, on what criterion, and what does each trade away?