Biotin (B7)
Eggs, Fish and meat, Nuts and seeds.
Back to TagsHair loss and brittle nails can come from genetics, thyroid disease, iron deficiency, autoimmune disease, illness, stress, medications, pregnancy/postpartum changes, or inadequate intake. High-dose biotin can also interfere with lab tests.
Source mix: Official Reference, Systematic Review, Academic Review, Food Database, Government Health Agency. Biotin Fact Sheet for Health Professionals Riboflavin Fact Sheet for Health Professionals Zinc Fact Sheet for Health Professionals Iron Fact Sheet for Health Professionals Effects of Oral Collagen for Skin Anti-Aging: A Systematic Review and Meta-Analysis Effects of Collagen Peptide Supplementation on Body Composition, Collagen Synthesis, and Recovery FoodData Central Mixing Medications and Dietary Supplements Can Endanger Your Health
Tag
Hair & Nails
Hair and nail references connect deficiency signs, connective-tissue nutrients, and bioactives commonly marketed for hair, nail, and structural support.
hairnailshair lossbrittle nailsthinning hairkeratinbiotincollagen
Linked Items
6
May Support
2
Deficiency Signs
3
Cautions
1
Quick Compare
| Item | Type | Relationship | Evidence |
|---|---|---|---|
| Biotin (B7) | nutrient | Deficiency Sign | Official NIH ODS deficiency framing; this does not mean high-dose biotin helps everyone. Official Reference |
| Riboflavin (B2) | nutrient | Deficiency Sign | Official NIH ODS deficiency framing. Official Reference |
| Zinc | nutrient | May Support | Official NIH ODS nutrient-role framing; excessive zinc can impair copper status. Official Reference |
| Iron | nutrient | Deficiency Sign | Official NIH ODS iron-deficiency/anemia framing; supplementation should follow need-based assessment. Official Reference |
| Collagen Peptides | bioactive | May Support | Systematic-review evidence for skin outcomes and review evidence for connective tissue; hair/nail claims need separate review. Systematic Review |
| Silica | bioactive | Caution / Limited Evidence | Basic catalog entry with food-source context. Food Database |
Foods First
Riboflavin (B2)
Dairy foods, Eggs, Meat, Fortified grains.
Zinc
Oysters and meat, Dairy foods, Legumes and seeds.
Iron
Red meat and shellfish, Legumes, Fortified cereals, Leafy greens.
Collagen Peptides
Gelatin, bone broth, skin-on poultry, fish skin, slow-cooked connective tissue.
Silica
Oats, barley, brown rice, bananas, green beans.
Medication & Safety Cautions
Biotin (B7)
Biotin deficiency is rare, but reported deficiency signs include thinning hair, brittle nails, and scaly red rash. | High-dose biotin can interfere with some laboratory tests.
Zinc
Zinc supports protein synthesis, immune function, and wound healing; deficiency can affect rapidly dividing tissues. | Long-term high-dose zinc can interfere with copper status.
Iron
Iron deficiency can contribute to fatigue and may be relevant in some hair-loss evaluations. | Iron overdose can be dangerous, especially for children. High-dose use should be guided by a clinician.
Collagen Peptides
Collagen peptides provide amino acids and peptides associated with connective tissues; skin evidence is stronger than hair-specific evidence in this app so far. | allergy | kidney disease
Silica
Silica is marketed for hair, skin, nails, and connective tissue, but claim-level evidence and product identity need more review before strong wording.
Key Studies & Fixed References
These are the dated references used for this tag. Live research searches can change; these links explain the fixed wording shown on this page.
NIH Office of Dietary Supplements | Acquired 2026-07-24 | Official Reference
Biotin deficiency signs, Skin rash, Hair loss.
NIH Office of Dietary Supplements | Acquired 2026-07-24 | Official Reference
Riboflavin deficiency signs, Skin disorders, Mouth and lip changes.
NIH Office of Dietary Supplements | Acquired 2026-07-23 | Official Reference
Zinc supplement forms, Elemental zinc context, Zinc absorption and iron interaction.
NIH Office of Dietary Supplements | Acquired 2026-07-23 | Official Reference
Heme and non-heme iron, Iron supplement forms, Elemental iron context.
Nutrients / PubMed | Acquired 2026-07-24 | Systematic Review
Hydrolyzed collagen, Skin hydration, Skin elasticity.
Amino Acids / PubMed | Acquired 2026-07-23 | Academic Review
Collagen and joint function, Collagen and exercise recovery, Collagen dose context.
U.S. Department of Agriculture | Acquired 2026-07-23 | Food Database
Food composition and natural source verification.
U.S. Food and Drug Administration | Acquired 2026-07-23 | Government Health Agency
Supplement-medication interaction warning language.
May Support
Zinc
nutrientOfficial Reference
Zinc supports protein synthesis, immune function, and wound healing; deficiency can affect rapidly dividing tissues.
Evidence note: Official NIH ODS nutrient-role framing; excessive zinc can impair copper status.
Sources: Zinc Fact Sheet for Health Professionals (2026-07-23)Official Reference
Collagen Peptides
bioactiveSystematic Review
Collagen peptides provide amino acids and peptides associated with connective tissues; skin evidence is stronger than hair-specific evidence in this app so far.
Evidence note: Systematic-review evidence for skin outcomes and review evidence for connective tissue; hair/nail claims need separate review.
Sources: Effects of Oral Collagen for Skin Anti-Aging: A Systematic Review and Meta-Analysis (2026-07-24)Systematic Review, Effects of Collagen Peptide Supplementation on Body Composition, Collagen Synthesis, and Recovery (2026-07-23)Academic Review
Deficiency Sign
Biotin (B7)
nutrientOfficial Reference
Biotin deficiency is rare, but reported deficiency signs include thinning hair, brittle nails, and scaly red rash.
Evidence note: Official NIH ODS deficiency framing; this does not mean high-dose biotin helps everyone.
Sources: Biotin Fact Sheet for Health Professionals (2026-07-24)Official Reference
Riboflavin (B2)
nutrientOfficial Reference
Riboflavin deficiency can include hair loss and skin or mouth changes.
Evidence note: Official NIH ODS deficiency framing.
Sources: Riboflavin Fact Sheet for Health Professionals (2026-07-24)Official Reference
Iron
nutrientOfficial Reference
Iron deficiency can contribute to fatigue and may be relevant in some hair-loss evaluations.
Evidence note: Official NIH ODS iron-deficiency/anemia framing; supplementation should follow need-based assessment.
Sources: Iron Fact Sheet for Health Professionals (2026-07-23)Official Reference
Caution / Limited Evidence
Silica
bioactiveFood Database
Silica is marketed for hair, skin, nails, and connective tissue, but claim-level evidence and product identity need more review before strong wording.
Evidence note: Basic catalog entry with food-source context.
Sources: FoodData Central (2026-07-23)Food Database, Mixing Medications and Dietary Supplements Can Endanger Your Health (2026-07-23)Government Health Agency