Vitamins & Minerals Supplements: What the Evidence Actually Shows 2026

🌿 Vitamins & minerals

Vitamins & Minerals: The Research-Backed Guide

Vitamin and mineral supplementation is most effective when correcting documented deficiency — and many deficiencies are more prevalent than widely recognised. Vitamin D deficiency affects 40% of Americans, magnesium deficiency affects 48–68%, and omega-3 insufficiency is nearly universal in people n

40%
Vitamin D deficient (US)
10
In-depth reviews
48%
Magnesium deficient
7
Key nutrients covered

The science behind this category

Vitamin and mineral supplementation is most effective when correcting documented deficiency — and many deficiencies are more prevalent than widely recognised. Vitamin D deficiency affects 40% of Americans, magnesium deficiency affects 48–68%, and omega-3 insufficiency is nearly universal in people not eating oily fish regularly. This hub covers our full vitamin and mineral research, with evidence graded by clinical trial quality.

All reviews in this category

Every article cites peer-reviewed primary sources. Last updated July 2026.

Article 01
Vitamin D Deficiency: The Silent Epidemic and How to Fix ItRead review →
Article 02
Best Magnesium Supplement 2026: Forms, Dosing, and What the Research ShowsRead review →
Article 03
Best Omega-3 Fish Oil Supplements 2026: EPA, DHA, and What the Research ShowsRead review →
Article 04
Best Electrolyte Supplements 2026: LMNT vs Liquid IV vs Nuun (Ranked by Science)Read review →
Article 05
Best Probiotic Supplements 2026: Gut Health, Strains, and What the Science SaysRead review →
Article 06
Best Supplements for Sleep 2026: What Science Says Actually WorksRead review →
Article 07
Moringa: Is the “Miracle Tree” Actually Miraculous? An Evidence-Based ReviewRead review →
Article 08
AG1 Review 2026: Is Athletic Greens Worth $79/Month?Read review →
Article 09
Colostrum Supplement Review 2026: Leaky Gut and Immunity EvidenceRead review →
Article 10
Best Supplements for Men Over 40: What the Evidence SupportsRead review →

Frequently asked questions

Do I need a multivitamin?
If you eat a varied, whole-food diet, a multivitamin provides minimal benefit for most nutrients. The exceptions are vitamin D (difficult to get from food), omega-3s (unless you eat oily fish 2–3 times per week), and magnesium (depleted by modern agricultural practices). Targeted supplementation of deficient nutrients outperforms a generic multivitamin.
Which form of magnesium is best?
Magnesium glycinate has the highest bioavailability and causes the least GI discomfort. Magnesium citrate is also well-absorbed. Magnesium oxide (the most common form in cheap supplements) has poor bioavailability of around 4%. Always check the form on the label.
What’s the difference between vitamin D2 and D3?
Vitamin D3 (cholecalciferol) is 87% more effective at raising serum 25(OH)D levels than D2 (ergocalciferol) and maintains those levels significantly longer. D3 is the form your skin produces from sunlight. Always supplement with D3, not D2.

Start with our most comprehensive review

Start with our vitamin D and magnesium reviews — covering the two most widespread deficiencies with the strongest evidence for correction.

Read the vitamin D guide →
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