Appendix H — Supplement Evidence Grades
Every supplement this book assessed, graded, in one table.
⚠️ Chapter 16 is the argument. This is the lookup.
⚠️ Chapter 38 §38.5 identified the ❌ and 🟠 verdicts as where most of this book's financial value sits. This appendix is where most of those verdicts are.
⚠️ Before the table
⚠️ Four things Chapter 16 established that change how you should read every row below.
⚠️ 1. "Can't hurt" is false. ⚠️ Walt Prosser's high-dose biotin produced a falsely elevated troponin and an unnecessary cardiac workup at 04:32. ⚠️ Supplements interact with assays, with medications and with each other.
⚠️ 2. Regulation is much lighter than for medicines in most countries. ⚠️ Content frequently differs from label; contamination and undeclared pharmaceutical ingredients are documented, particularly in sports and weight-loss categories.
⚠️ 3. Supplementing a non-deficient person almost never helps (Ch 13's threshold). ⚠️ The dose– response is J-shaped for several nutrients: too little is bad, adequate is good, and more is not better.
⚠️ 4. And the beta-carotene template is the pattern to expect (Ch 2): ⚠️ a nutrient observed in healthy diets, isolated into a pill, tested — and doing nothing, or harm.
⚠️ ✅ Genuinely indicated, for specific people
| ⚠️ Supplement | ⚠️ For whom | ⚠️ Chapter |
|---|---|---|
| ⚠️ Folic acid | ⚠️ Preconception and early pregnancy. One of the clearest wins in the book | 13, 25 |
| ⚠️ Vitamin D | ⚠️ Deficiency, limited sun exposure, darker skin at high latitude, older adults, winter | 13, 14 |
| ⚠️ Vitamin B12 | ⚠️ Vegans, older adults, malabsorption, long-term metformin | 13, 16, 26 |
| ⚠️ Iron | ⚠️ DIAGNOSED deficiency only — ⚠️ and harmful without it | 14, 15 |
| ⚠️ Iodine | ⚠️ Pregnancy; populations without iodized salt | 14, 25 |
| ⚠️ Creatine monohydrate | ⚠️ Strength and power performance. The best-evidenced sports supplement there is | 16, 23 |
| ⚠️ Oral rehydration solution | ⚠️ Actual dehydration — illness, heavy sweat losses | 15 |
| ⚠️ Prescribed clinical supplementation | ⚠️ Malabsorption, post-surgical, diagnosed deficiency, clinical nutrition support | 29 |
⚠️ Every row above is conditional. None of them is "everyone should take this."
⚠️ 🟢 Probably works, for a defined purpose
| ⚠️ Supplement | ⚠️ For what | ⚠️ Chapter |
|---|---|---|
| ⚠️ Caffeine | ⚠️ Endurance and performance. Real, dose-dependent, tolerance develops | 16, 23 |
| ⚠️ Beta-alanine | ⚠️ High-intensity efforts of roughly 1–4 minutes | 23 |
| ⚠️ Nitrate / beetroot juice | ⚠️ Endurance, modest effect | 23 |
| ⚠️ Sodium bicarbonate | ⚠️ High-intensity buffering; gastrointestinal cost is real | 23 |
| ⚠️ Psyllium | ⚠️ LDL, glycaemia, stool normalization | 11, 16 |
| ⚠️ Protein powder | ⚠️ Convenience, not magic. Food does the same job | 8, 23 |
| ⚠️ Fermented foods | ⚠️ Not a supplement, and the one dietary microbiome intervention with support | 27 |
⚠️ 🟡 Unclear, or it depends
| ⚠️ Supplement | ⚠️ Why it is here | ⚠️ Chapter |
|---|---|---|
| ⚠️ Fish oil / omega-3 capsules | ⚠️ Eating oily fish is 🟢; the capsules have underperformed in large trials | 19 |
| ⚠️ Probiotics, general | ⚠️ Strain-specific and condition-specific. Most products specify neither | 27 |
| ⚠️ Magnesium | ⚠️ Genuine in deficiency; the general-population case is weak | 14, 33 |
| ⚠️ Vitamin D beyond deficiency correction | ⚠️ The trials for non-skeletal outcomes have largely disappointed | 13 |
| ⚠️ Collagen | ⚠️ Some joint and skin signal; mechanism is not what marketing claims | 16 |
| ⚠️ Melatonin | ⚠️ Real for circadian shift; not a general sleep aid | 16 |
| ⚠️ Multivitamins in the well-fed | ⚠️ Largely inert. Insurance against a risk most people do not have | 13 |
⚠️ 🟠 Probably doesn't work
| ⚠️ Supplement | ⚠️ Chapter |
|---|---|
| ⚠️ Antioxidant supplements for disease prevention — and some caused harm | 2, 13 |
| ⚠️ Vitamin E supplementation | 13 |
| ⚠️ BCAAs when total protein is adequate | 23 |
| ⚠️ Glutamine for the general population | 23 |
| ⚠️ "Testosterone boosters" | 16 |
| ⚠️ Most "immune support" formulations | 16 |
| ⚠️ Apple cider vinegar for weight or glycaemia | 17 |
| ⚠️ MTHFR-targeted specialty folate for people eating adequate folate | 35 |
| ⚠️ Broad micronutrient panels in asymptomatic people (the test, not a supplement — it generates them) | 13, 35 |
⚠️ ❌ Not supported
| ⚠️ Supplement or product | ⚠️ Chapter |
|---|---|
| ⚠️ Detox and cleanse products | 17 |
| ⚠️ "Fat burners" and thermogenics | 16 |
| ⚠️ L-carnitine for fat loss | 6, 16 |
| ⚠️ Exogenous ketones for burning body fat | 6 |
| ⚠️ Raspberry ketones, garcinia, and the weight-loss ingredient carousel | 16, 17 |
| ⚠️ Alkaline water and alkaline diets | 17 |
| ⚠️ Colloidal silver | 16 |
| ⚠️ IgG "food sensitivity" panels (a test that sells eliminations) | 28, 35 |
| ⚠️ Hair mineral analysis | 35 |
| ⚠️ Homeopathic preparations | 17 |
| ⚠️ "Superfood" powders as a category | 17 |
⚠️ ⚗️ Untested in humans, at meaningful doses
| ⚠️ Supplement | ⚠️ Note |
|---|---|
| ⚠️ Most longevity compounds — NMN, NR, resveratrol, spermidine | ⚠️ Animal and mechanistic data; human outcome data absent. ⚠️ Untested is not false — and it is not a reason to buy |
| ⚠️ Many novel probiotic strains | 27 |
| ⚠️ Most "nootropic" nutritional compounds | ⚠️ Marketed far ahead of testing |
⚠️ Safety notes worth knowing
| ⚠️ Issue | ⚠️ Detail |
|---|---|
| ⚠️ Biotin and lab assays | ⚠️ High-dose biotin interferes with troponin, thyroid and other immunoassays. Tell any clinician taking blood. Walt's ER visit (Ch 16) |
| ⚠️ Vitamin K and warfarin | ⚠️ Consistency matters more than quantity (Ch 16) |
| ⚠️ Iron without deficiency | ⚠️ Gastrointestinal harm, and a genuine risk in haemochromatosis (Ch 14) |
| ⚠️ Vitamin A in pregnancy | ⚠️ Retinol is teratogenic at high doses. Check liver and supplement sources (Ch 25) |
| ⚠️ Selenium | ⚠️ Narrow window between requirement and toxicity (Ch 14) |
| ⚠️ Vitamin B6 | ⚠️ Chronic high doses cause peripheral neuropathy (Ch 13) |
| ⚠️ St John's wort | ⚠️ Induces drug metabolism; interacts with many medicines including contraceptives (Ch 16) |
| ⚠️ Grapefruit | ⚠️ Not a supplement, and interacts with several drug classes (Ch 16) |
| ⚠️ Sports and weight-loss categories | ⚠️ Highest documented rates of contamination and undeclared ingredients (Ch 16, 23) |
| ⚠️ Refeeding | ⚠️ Nutritional restoration in the significantly undernourished is a monitored medical procedure (Ch 29, 34) |
⚠️ The audit
Chapter 16's exercise, and Walt's outcome was nine to two.
Step 1 — ⚠️ List everything you take, with the annual cost.
| ⚠️ Supplement | ⚠️ Why I started | ⚠️ Grade above | ⚠️ Annual cost |
|---|---|---|---|
Step 2 — ⚠️ For each, answer three questions.
⚠️ Do I have the condition it is indicated for — DIAGNOSED, not suspected? ⚠️ What would tell me it is working? ⚠️ Who recommended it, and were they selling it?
Step 3 — ⚠️ Stop everything that is 🟠, ❌ or ⚗️.
Step 4 — ⚠️ For everything 🟡, set a date to stop and see.
Step 5 — ⚠️ And total the annual cost of what you stopped.
⚠️ Walt's was around $1,700, and the seven he stopped included the one that sent him to an emergency department.
⚠️ Chapter 35 §35.13 makes the comparison this appendix is really about: that money buys a great deal of the food in Appendix C.