An evidence-based guide to what works, what doesn't, and what matters for men's health.
Vitamins & Supplements
An evidence-based guide to what works, what doesn't, and what matters for men's health.
Quick summary
- This page shows which vitamins and supplements have strong science behind them.
- We focus on vitamin D, omega-3, creatine, and magnesium — the top proven picks.
- Testing for real gaps works better than taking a general multivitamin every day.
- Your doctor can match the right doses to your lab results and health goals.
This content is for educational purposes only. It does not constitute medical advice, replace clinical consultation, or serve as a treatment plan. All decisions require individual physician evaluation and oversight.
Vitamins & Supplements: An Evidence-Based Guide
The global dietary supplement market exceeded $150 billion annually in 2022 — driven by marketing budgets that dwarf the investment in clinical research behind most products. The overwhelming majority of supplements marketed for health, energy, performance, and longevity either lack adequate human clinical trial evidence, are tested at doses too low to produce meaningful effects, or contain active ingredients at amounts below the thresholds used in positive studies.
This does not mean supplements are uniformly ineffective. Several have compelling Grade A evidence from multiple randomized controlled trials and address deficiencies that are genuinely prevalent and genuinely consequential. At Advanced Vitality Group, supplement recommendations are held to the same evidence standard as all clinical decisions.
Key Takeaways
Vitamin D deficiency (25-OH D < 20 ng/mL) affects ~40% of US adults — correction has Grade A evidence for bone health, muscle function, immune regulation, and reduced fracture risk.
Omega-3 fatty acids (EPA + DHA): the REDUCE-IT trial (n = 8,179, Bhatt DL et al., NEJM, 2019) showed 25% reduction in major cardiovascular events with 4 g/day icosapentaenoic acid.
Creatine monohydrate: Grade A evidence across 500+ studies for muscle performance, lean mass (+1.37 kg vs. training alone), and cognitive function in older adults.
Magnesium: ~45–48% of Americans consume below the RDA; deficiency impairs ATP synthesis, sleep quality, blood pressure regulation, and insulin sensitivity.
NAD+ precursors (NMN, NR): Phase 1/2 RCT evidence for increasing cellular NAD+ and improving mitochondrial markers; large Phase 3 trials ongoing.
Most people eating varied diets do not need a general multivitamin — specific deficiency correction has better evidence than broad multivitamin use.
The Evidence Hierarchy: How to Evaluate a Supplement Claim
| Evidence Level | Definition | Examples | Reliability |
|---|---|---|---|
| Grade A — Strong | Multiple large RCTs, meta-analyses | Vitamin D, Omega-3, Creatine monohydrate, Folic acid | Highest |
| Grade B — Moderate | Multiple smaller RCTs | Magnesium, NAD+ precursors, Vitamin K2, CoQ10, Zinc | Moderate |
| Grade C — Preliminary | Limited RCTs, primarily in vitro/animal | Urolithin A, GHK-Cu, most adaptogens | Emerging |
| Grade D — Insufficient | Marketing claims, no meaningful RCT | Most proprietary blends, "detox" supplements | Not sufficient |
Supplements with Grade A Evidence
Vitamin D — The Most Prevalent Correctable Deficiency
A nationally representative survey (Forrest KY & Stuhldreher WL, Nutrition Research, 2011) found that 41.6% of US adults have 25-OH vitamin D below 20 ng/mL (clinical deficiency threshold), rising to 69.2% in Hispanic Americans and 82.1% in Black Americans. Confirmed deficiency has Grade A evidence for its consequences on bone health, muscle function, immune regulation, and mood.
Optimal target: 25-OH vitamin D at 40–60 ng/mL for most adults. Standard correction doses: 2,000–5,000 IU vitamin D3 per day. Retest at 3 months to confirm adequacy.
Omega-3 Fatty Acids (EPA + DHA) — Cardiovascular and Anti-Inflammatory
The landmark REDUCE-IT trial (Bhatt DL et al., NEJM, 2019) randomized 8,179 statin-treated patients with elevated triglycerides to 4 g/day icosapentaenoic acid or placebo. Over median 4.9 years, IPE reduced major adverse cardiovascular events by 25%. A meta-analysis of 68 RCTs (Calder PC et al., Nutrients, 2017) found omega-3 supplementation significantly reduced circulating CRP, IL-6, and TNF-α.
Practical guidance: 2–4 g/day combined EPA+DHA for general anti-inflammatory and cardiovascular support; prescription-grade IPE for patients with elevated triglycerides. Target omega-3 index above 8%.
Creatine Monohydrate — Performance and Cognitive Function
The ISSN 2017 Position Stand — reviewing over 500 published studies — concluded creatine monohydrate is the most effective ergogenic nutritional supplement available. Additionally, a systematic review of 6 RCTs found significant cognitive benefits in working memory and processing speed. Standard dose: 3–5 g/day creatine monohydrate. See our Creatine Gummies page.
Supplements with Grade B Evidence
Magnesium — The Under-Recognized Deficiency
Magnesium is a cofactor in more than 300 enzymatic reactions. An estimated 45–48% of Americans consume less than the RDA (420 mg/day for men 31+). Meta-analysis of 34 RCTs found significant blood pressure reduction with supplementation. Magnesium supplementation improves insulin sensitivity and sleep quality in adults with poor sleep.
Bioavailability: magnesium glycinate and malate have superior GI tolerability. Typical therapeutic dose: 200–400 mg elemental magnesium per day.
NAD+ Precursors (NMN and NR)
NAD+ levels decline approximately 40–60% between early adulthood and age 60. Phase 1/2 RCTs have established that both NMN and NR safely and measurably raise cellular NAD+ levels in humans. A key RCT (Yoshino M et al., Science, 2021) found NMN at 250 mg/day significantly increased skeletal muscle NAD+ and improved insulin sensitivity in postmenopausal women with prediabetes.
What About Multivitamins?
The Physicians' Health Study II (Gaziano JM et al., JAMA, 2012) — 14,641 male physicians over 11 years — found a statistically significant 8% reduction in total cancer incidence with daily multivitamin use, but no significant effect on cardiovascular or all-cause mortality. The USPSTF 2022 evidence review concluded there was insufficient evidence to recommend multivitamins for cancer or CVD prevention in healthy adults. Targeted correction of confirmed specific deficiencies has more evidence and more predictable benefit than a generic multivitamin.
Supplements by Health Goal: Evidence Summary
| Health Goal | Most Evidence-Supported | Evidence Level |
|---|---|---|
| Deficiency correction | Vitamin D3, Magnesium, Iron, B12 | Grade A |
| Cardiovascular health | Omega-3 (EPA+DHA ≥ 2 g/day); prescription IPE | Grade A |
| Muscle performance/hypertrophy | Creatine monohydrate (3–5 g/day) | Grade A |
| Inflammation reduction | Omega-3 fatty acids | Grade A |
| Cellular energy/mitochondria | NAD+ precursors | Grade B |
| Sleep quality | Magnesium glycinate (200–400 mg) | Grade B |
| Skin and connective tissue | Hydrolyzed collagen (5–10 g/day) + Vitamin C | Grade B |
| Cognitive function | Creatine monohydrate; Omega-3 DHA; Vitamin D | Grade A–B |
Frequently Asked Questions
Scientific References
- Forrest KY, Stuhldreher WL. “Prevalence and correlates of vitamin D deficiency in US adults.” Nutrition Research. 2011;31(1):48–54.
- Bhatt DL, et al. “Cardiovascular risk reduction with icosapentaenoic acid (REDUCE-IT).” NEJM. 2019;380(1):11–22.
- Kreider RB, et al. “ISSN position stand: safety and efficacy of creatine supplementation.” JISSN. 2017;14:18.
- Yoshino M, et al. “Nicotinamide mononucleotide increases muscle insulin sensitivity.” Science. 2021;372(6547):1224–1229.
- Rosanoff A, et al. “Suboptimal magnesium status in the United States.” Nutrition Reviews. 2012;70(3):153–164.
- Gaziano JM, et al. “Multivitamins in the prevention of cancer in men (PHSII).” JAMA. 2012;308(18):1871–1880.
- Calder PC. “Omega-3 fatty acids and inflammatory processes.” Biochemical Society Transactions. 2017;45(5):1105–1115.
- Avgerinos KI, et al. “Effects of creatine supplementation on cognitive function.” Experimental Gerontology. 2018;108:166–173.
- Lanhers C, et al. “Creatine supplementation and lower limb strength performance.” European Journal of Sport Science. 2015;15(1):9–16.
Schedule a consultation to design an evidence-based supplement strategy grounded in your biomarkers.