Supplement Research & Studies
Landmark clinical studies on the ingredients in our encyclopedia. Filter by ingredient, study type, or year. Every citation is verified and links to its PubMed entry — no scraped abstracts, no cherry-picking. We add to this set as we curate evidence for new entries.
- Marine n-3 Fatty Acids and Prevention of Cardiovascular Disease and Cancer (VITAL trial) ↗Manson JE, Cook NR, Lee IM, et al. · New England Journal of Medicine
Large primary-prevention RCT (n=25,871) found n-3 fatty acid supplementation did not reduce major cardiovascular events overall but did reduce myocardial infarction risk, with greatest benefit in low-fish-intake participants.
- International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine ↗Kreider RB, Kalman DS, Antonio J, et al. · Journal of the International Society of Sports Nutrition
Reviews 500+ studies and concludes creatine monohydrate is the most effective ergogenic nutritional supplement for high-intensity exercise and lean body mass, with an excellent safety profile across populations.
- Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data ↗Martineau AR, Jolliffe DA, Hooper RL, et al. · BMJ
Individual-participant meta-analysis of 25 RCTs (n=10,933) found vitamin D supplementation reduced risk of acute respiratory tract infection, with greatest benefit in baseline-deficient participants and daily/weekly (not bolus) dosing.
- Zinc lozenges and the common cold: a meta-analysis comparing zinc acetate and zinc gluconate, and the role of zinc dosage ↗Hemilä H · JRSM Open
Meta-analysis of 7 RCTs (n=575) found zinc lozenges (≥75mg/day elemental zinc) shortened cold duration by ~33%, with no significant difference between acetate and gluconate forms.
- Effects of magnesium supplementation on blood pressure: a meta-analysis of randomized double-blind placebo-controlled trials ↗Zhang X, Li Y, Del Gobbo LC, et al. · Hypertension
Meta-analysis of 34 trials (n=2,028) found magnesium supplementation at a median dose of 368mg/day for 3 months significantly reduced systolic BP by 2.00 mmHg and diastolic BP by 1.78 mmHg.
- Vitamin B12 deficiency ↗Stabler SP · New England Journal of Medicine
Comprehensive clinical review of B12 deficiency diagnosis and treatment, noting that serum B12 alone is unreliable and that methylmalonic acid (MMA) and homocysteine are more sensitive markers of functional deficiency.
- Comparison of vitamin D2 and vitamin D3 supplementation in raising serum 25-hydroxyvitamin D status: a systematic review and meta-analysis ↗Tripkovic L, Lambert H, Hart K, et al. · American Journal of Clinical Nutrition
D3 (cholecalciferol) raised serum 25(OH)D significantly more effectively than D2 (ergocalciferol) at equivalent doses, supporting D3 as the preferred form.
- The effect of magnesium supplementation on primary insomnia in elderly: a double-blind placebo-controlled clinical trial ↗Abbasi B, Kimiagar M, Sadeghniiat K, et al. · Journal of Research in Medical Sciences
8-week RCT in elderly with insomnia: 500mg/day magnesium significantly improved subjective insomnia score, sleep efficiency, sleep onset latency, and serum melatonin concentration.
- A prospective, randomized double-blind, placebo-controlled study of safety and efficacy of a high-concentration full-spectrum extract of ashwagandha root in reducing stress and anxiety in adults ↗Chandrasekhar K, Kapoor J, Anishetty S · Indian Journal of Psychological Medicine
60-day double-blind RCT (n=64) using 300mg KSM-66 ashwagandha twice daily significantly reduced perceived stress (PSS) and serum cortisol vs placebo.
- N-acetylcysteine in psychiatry: current therapeutic evidence and potential mechanisms of action ↗Dean O, Giorlando F, Berk M · Journal of Psychiatry and Neuroscience
Reviews evidence for NAC as an adjunctive psychiatric treatment, with strongest data in trichotillomania, OCD, addictive behaviors, and as a glutathione precursor for oxidative stress reduction.
- Improving effects of the mushroom Yamabushitake (Hericium erinaceus) on mild cognitive impairment: a double-blind placebo-controlled clinical trial ↗Mori K, Inatomi S, Ouchi K, et al. · Phytotherapy Research
16-week RCT in older adults with mild cognitive impairment (n=30) found 3g/day lion's mane significantly improved cognitive function score vs placebo, with effects diminishing 4 weeks post-cessation.
- L-theanine, a natural constituent in tea, and its effect on mental state ↗Nobre AC, Rao A, Owen GN · Asia Pacific Journal of Clinical Nutrition
Reviews EEG and cognitive evidence that L-theanine increases alpha wave activity (associated with calm alertness) and, when combined with caffeine, improves attention without sedation.
- Efficacy of berberine in patients with type 2 diabetes mellitus ↗Yin J, Xing H, Ye J · Metabolism
3-month RCT in newly diagnosed T2DM (n=84) found berberine 500mg three times daily reduced HbA1c, fasting glucose, and postprandial glucose comparably to metformin.
- Effects of creatine supplementation and resistance training on muscle strength and weightlifting performance ↗Rawson ES, Volek JS · Journal of Strength and Conditioning Research
Meta-analysis of 22 trials showing creatine + resistance training increased 1RM bench press by ~6.85kg and squat by ~9.76kg vs placebo + training.