Glossary
Supplements
Updated February 28, 2026
Supplements can be useful when food intake, schedule variability, and recovery demands create persistent gaps in key nutrients. They are most effective as a correction layer after diet quality and consistency are already solid.
Evidence tiers
| Tier | Supplements | Typical dose | Strength of evidence |
|---|---|---|---|
| Tier 1 | Creatine monohydrate | 3–5 g daily | Strong. Consistent benefits for strength and power |
| Tier 1 | Vitamin D | 1000–2000 IU daily (varies by labs) | Strong when deficient or insufficient |
| Tier 1 | Omega-3 (EPA+DHA) | 1–2 g daily | Strong for recovery and inflammation management |
| Tier 1 | Protein powder (whey, casein, pea, rice blend) | To fill daily protein gap | Strong as a convenience tool for total intake |
| Tier 2 | Magnesium (glycinate or citrate) | 200–400 mg elemental | Moderate. Most useful when dietary intake is low |
| Tier 2 | Iron | Per clinician guidance | Moderate. Only when lab-confirmed deficiency |
| Tier 2 | Caffeine | 3–6 mg/kg body weight | Moderate to strong for acute performance |
| Tier 2 | Beta-alanine | 3.2–6.4 g daily | Moderate. Best fit for hard efforts lasting about 1 to 4 minutes |
| Tier 2 | Collagen peptides | 10–15 g around tendon loading | Context-dependent. Most plausible for connective tissue support |
| Tier 3 | Most others (BCAAs, glutamine, fat burners) | Varies | Weak or context-dependent. Limited general value |
Strategic supplement use
Supplements are most reliable when they solve a clear gap. They rank behind food pattern, hydration, sleep, and training dose.
| Use case | First priority | Supplement role |
|---|---|---|
| Low micronutrient density | Increase whole-food diversity | Use targeted capsules or powders only where deficiency risk remains |
| Clinical or lab-confirmed deficits | Work with clinician guidance | Use a dose tied to markers and recheck schedule |
| Travel or constrained preparation windows | Build resilient food basics first | Use only compact supports that match established schedule goals |
| Recovery under high load | Resolve sleep and stress load | Use short-cycle support rather than permanent stacking |
Interaction cautions
| Combination | Risk | Spacing rule |
|---|---|---|
| Iron + calcium | Calcium reduces iron absorption at same meal | Separate by 2+ hours |
| Zinc + copper | High zinc depletes copper over time | If supplementing zinc long-term, add copper |
| Vitamin D + no fat in meal | Fat-soluble vitamin needs dietary fat for uptake | Take with a fat-containing meal |
| Caffeine + iron | Caffeine reduces non-heme iron absorption | Separate by 1+ hour |
| Multiple fat-soluble vitamins | Compete for absorption when taken together | Spread across meals if doses are high |
Foundation before supplementation
Treat a stack like an experiment with three checkpoints: dose, duration, and evidence.
| Checkpoint | What to verify | Why it matters |
|---|---|---|
| Food baseline | Protein target, vegetable color range, carbohydrate timing, hydration | Supplements improve compliance, not core quality |
| Biomarker signal | Recent labs, symptom pattern, trend duration | Avoid chasing one-off data noise |
| Interaction profile | Medication conflicts, timing clashes, duplicate nutrients | Prevent absorption losses and unnecessary dose stacking |
Monitoring and adjustment protocols
Keep notes on dose, meal timing, and outcomes for 3 to 8 weeks, then decide whether to continue, lower, or stop.
| Indicator | Continue for now | Pause and reassess |
|---|---|---|
| Fatigue and workout quality are stable | No new symptoms or digestive changes | Repeated sleep disruption or recurring upset stomach |
| Appetite and weight trend remain controlled | No missed meals or mood instability | New medical symptoms or worsening baseline conditions |
| No duplicate nutrients across products | Labs remain within target ranges | Conflicting products or suspected interaction |
If you want a deeper read on individual micronutrients, start with Micronutrients, Vitamin D, and Magnesium. Then use B Vitamins and Iron Levels for focused follow-through. For creatine, start with The Complete Guide to Creatine (2026), then use Creatine for Women for the female-specific evidence and body-weight questions.