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Hair Skin & Nails

Nature's Bounty Optimal Solutions
4.6
★ ★ ★ ★ ★
(27867 ratings)
Phosphorus 90 mg
Biotin 3000 mcg
Manganese 2 mg
Niacin 25 mg
PABA 10 mg
Vitamin A 5000 IU
Vitamin D 1000 IU
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Score70
Useful vitamins, zinc, and high-dose biotin provide broad beauty-nutrient coverage, but collagen and horsetail are only token additions. Basic forms and laboratory-test interference from biotin reduce its appeal.
How scoring works
Quantity:60 Tablet(s) • (20 servings)
Goals:
Nail Health
Immunity

Score 70

Useful vitamins, zinc, and high-dose biotin provide broad beauty-nutrient coverage, but collagen and horsetail are only token additions. Basic forms and laboratory-test interference from biotin reduce its appeal.
How scoring works
$7.49($0.37 per serving)
iHerb
$ 8.36
Vitacost
$ 9.03
Walmart
$ 9.69
Amazon
$ 7.49
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Analysis

The three-tablet serving provides vitamin C, vitamin D3, zinc, manganese, and several B vitamins that can support normal hair, skin, and nail nutrition when intake is inadequate. Biotin is supplied at a very high amount, while zinc is present at a practical level.

The structural ingredients are weak: hydrolyzed collagen is only 50 mg and horsetail powder only 3 mg. Magnesium oxide, calcium carbonate, folic acid, cyanocobalamin, and synthetic vitamin E also keep ingredient quality fairly basic.

People seeking nutritional-gap coverage may find the formula useful, but it is not a meaningful collagen supplement. The three-tablet serving and high biotin amount are important practical drawbacks, especially before laboratory testing.

Who is it for
  • Adults seeking broad hair and nail nutrient coverage
  • People with low dietary intake of zinc or selected B vitamins
  • Users comfortable taking three tablets daily
Best for
  • High-dose biotin supplementation
  • Basic hair and nail nutrition
  • Combining zinc, vitamin C, and B vitamins

Pros

  • Provides 3,000 mcg of biotin
  • Includes practical zinc and vitamin C amounts
  • Supplies vitamin D3 and a broad B-vitamin base
  • Low serving cost for broad coverage

Cons

  • Collagen amount is too small for meaningful structural support
  • Horsetail is present only at a trace amount
  • Uses several basic or synthetic nutrient forms
  • Requires three tablets per serving
  • Very high biotin is unnecessary for many users

Warnings

  • High-dose biotin can distort thyroid, cardiac, hormone, and other laboratory tests; disclose use and follow testing instructions before blood work.
  • Retinyl palmitate is preformed vitamin A, so pregnancy and use of other retinol supplements require careful total-intake review.
  • The calcium content can reduce absorption of levothyroxine and tetracycline-class antibiotics when taken together, so dosing may need separation.

Nutrient quality

55 Moderate impact

Biotin anchors the intended use, but weak structural ingredients and several basic forms limit formula depth. Tiny collagen and horsetail amounts make the design feel padded.

.

Ingredient transparency

71 High impact

Most active amounts are disclosed, but duplicated ingredient entries create avoidable ambiguity. Complete directions and non-active ingredients are not supplied.

.

Customer satisfaction

70 High impact

The supplied average is strong, and the rating count is very large. Specific firsthand feedback is absent, so repeated complaints and purpose fit cannot be assessed.

.

Value for money

85 Highest impact

The low serving cost supports strong value for broad daily coverage. Ordinary forms and a few weak amounts keep it from being exceptional.

.
Report analysis

Goals

Nail Health
Nail Health
Impact
Highest effect
A- Goal FitB+ Strength of SupportA- CoverageB+ Formula Quality
Collagen · 50 mgBiotin · 3000 mcgHorsetail · 3 mg

D-biotin, zinc, vitamin C, horsetail, and hydrolyzed collagen create a focused nail-support blend. The expected benefit is greatest when the relevant nutrient intake is inadequate.

Biotin is strong, but collagen and horsetail are token amounts that limit structural depth. Nails grow slowly, so any change would appear in new nail over time rather than repair the existing plate.

Study evidence
Biotin Supportive 8 studies
Collagen Supportive 4 studies
Horsetail Not classified

No linked studies yet.

Vitamin C Supportive 1 study
Zinc No effect 1 study
Immunity
Immunity
Impact
High effect
B Goal FitB- Strength of SupportC+ CoverageD Formula Quality
Magnesium · 50 mgVitamin C · 60 mgZinc · 7.5 mgVitamin A · 5000 IUVitamin D · 1000 IU

Vitamin A, vitamin C, vitamin D3, and zinc provide several foundations for normal immune function. Cholecalciferol and zinc gluconate are clearly identified forms.

Vitamin C and zinc amounts are modest, and selenium is absent. The formula is primarily built around hair, skin, and nail support, so many ingredients do not deepen its immune contribution.

Study evidence
Vitamin A Supportive 107 studies
Vitamin C Supportive 53 studies
Vitamin D Supportive 85 studies
Zinc Supportive 73 studies
Hair Health
Hair Health
Impact
Moderate effect
C+ Goal FitC- Strength of SupportC CoverageC+ Formula Quality
Biotin · 3000 mcgVitamin D · 1000 IUZinc · 7.5 mgVitamin C · 60 mgCollagen · 50 mg

D-biotin at 3,000 mcg, zinc gluconate, vitamin D3, vitamin C, and vitamin A create a clearly hair-oriented nutrient formula. The collagen amount is only 50 mg and horsetail is just 3 mg, so the two headline structural ingredients are token additions.

The product may help cover selected nutrient gaps but does not provide enough structural material for a complete hair strategy. High-dose biotin may distort thyroid, hormone, or cardiac troponin blood tests, so it should be disclosed before laboratory testing.

Study evidence
Biotin Supportive 4 studies
Collagen Supportive 3 studies
Horsetail Not classified

No linked studies yet.

Vitamin A Disputed 13 studies
Vitamin C Mixed 5 studies
Vitamin D Disputed 34 studies
Zinc Supportive 22 studies
General Health
General Health
Impact
Moderate effect
C+ Goal FitC- Strength of SupportC CoverageD+ Formula Quality
Folate · 200 mcgVitamin B12 · 8 mcgVitamin D · 1000 IUMagnesium · 50 mgCollagen · 50 mgZinc · 7.5 mgVitamin C · 60 mg

Vitamin D3, zinc, vitamin C, and several B vitamins provide moderate foundational nutritional coverage. The formula is still shaped around hair, skin, and nail support rather than comprehensive daily resilience.

Collagen and horsetail are included at trace amounts, while magnesium uses a low-absorption oxide form. The 3,000 mcg biotin amount can interfere with some laboratory tests, so it should be disclosed before blood work.

Study evidence
Collagen Supportive 31 studies
Folate Supportive 80 studies
Magnesium Supportive 114 studies
Vitamin C Supportive 56 studies
Vitamin D Supportive 115 studies
Zinc Supportive 60 studies
Skin Health
Skin Health
Impact
Moderate effect
C Goal FitD+ Strength of SupportC- CoverageC+ Formula Quality
Zinc · 7.5 mgVitamin C · 60 mgCollagen · 50 mgVitamin E · 15 IU

Vitamin A, vitamin C, zinc, and biotin provide basic support for skin turnover and tissue maintenance. Collagen and horsetail appear on the label, but both are far below useful targeted amounts.

The formula is more persuasive for correcting nutrient gaps than for changing skin structure or hydration. The 3,000 mcg biotin amount can distort thyroid, hormone, or cardiac troponin blood tests and should be disclosed before laboratory testing.

Study evidence
Biotin Supportive 10 studies
Collagen Supportive 62 studies
Vitamin A Supportive 106 studies
Vitamin C Supportive 53 studies
Vitamin E Supportive 38 studies
Zinc Supportive 66 studies

Ingredients

IngredientAmount per serving
Vitamin A (Retinyl Palmitate)
 5000 IU
Vitamin C (Ascorbic Acid)
 60 mg
Vitamin D (Cholecalciferol, Vitamin D3)
 1000 IU
Vitamin E (DL-Alpha-Tocopheryl Acetate)
 15 IU
Thiamine (Thiamine Hydrochloride, Vitamin B1)
 5 mg
Riboflavin (Vitamin B2)
 2 mg
Niacin (Niacinamide)
 25 mg
Vitamin B6 (Pyridoxine Hydrochloride)
 5 mg
Folic Acid
200 mcg
Vitamin B12 (Cyanocobalamin)
 8 mcg
Biotin (D-Biotin)
 3000 mcg
Pantothenic Acid (D-Calcium Pantothenate)
 15 mg
Calcium (Calcium Carbonate, Dicalcium Phosphate)
 200 mg
Phosphorus (Dicalcium Phosphate)
 90 mg
Magnesium (Magnesium Oxide)
 50 mg
Zinc (Zinc Gluconate)
 7.5 mg
Manganese (Manganese Gluconate)
 2 mg
PABA
10 mg
Choline Bitartrate
10 mg
Inositol
30 mg
Citrus Bioflavonoid/Rutin Complex
38 mg
Horsetail powder
3 mg
Collagen (hydrolyzed Gelatin)
 50 mg
Gluten Free Adults 18–50 Dairy Free Sugar Free
Report overview
Phosphorus (Dicalcium Phosphate) · 90 mg OverallScore83
B Active Ingredient Quality & BioavailabilityB Dose, Safety & Label TransparencyA+ Value

Dicalcium phosphate is a clearly identified and reliable mineral salt, although phosphorus is secondary to the product's main purpose. The elemental amount is at the lower end of supplementation, and the serving requires several caplets. Low serving cost supports strong price efficiency.

View ingredientView products
Niacin (Niacinamide) · 25 mg OverallScore82
B+ Active Ingredient Quality & BioavailabilityA- Dose, Safety & Label TransparencyB- Value

Niacinamide is well matched to a hair, skin, and nails formula and is supplied at a suitable multinutrient amount. The coated caplet lacks a defined release technology, but the form itself has low flush potential. A modest serving cost and broad nutrient profile provide good practical value.

View ingredientView products
Biotin (D-Biotin) · 3000 mcg OverallScore82
A Active Ingredient Quality & BioavailabilityB+ Dose, Safety & Label TransparencyC Value

Hair Skin & Nails specifies d-Biotin, while its tablet format has no listed artificial color or sweetener. The exact 3000 mcg amount is in the moderately high hair and nail range. The 3000 mcg dose may distort some thyroid, hormone, or cardiac troponin blood tests, so it should be disclosed before laboratory testing.

View ingredientView products
Loading alternative details
68 Performance

Hair Vitamins

SugarBearHair
A potentially better match in selected areas comes from 5,000 mcg of biotin with vitamin D3, vitamin C, zinc citrate, and pantothenic acid. Compared with the original beauty formula with 3,000 mcg of biotin but only 50 mg of collagen and 3 mg of horsetail, the ingredient focus is directly aligned with hair and nail support, although the supporting nutrient amounts are modest and high-dose biotin can distort some laboratory tests.
65 Performance

Extra Strength Hair Skin & Nails

Nature's Bounty Optimal Solutions
A potentially better match in selected areas comes from 5,000 mcg of biotin with vitamin D3, zinc, 50 mg of collagen, and 30 mg of hyaluronic acid. Compared with the original beauty formula with 3,000 mcg of biotin but only 50 mg of collagen and 3 mg of horsetail, it places more emphasis on biotin and hydration-related hyaluronic acid, although collagen and horsetail remain too small to provide much structural support.
55 Performance

Enzyme Nutrition Multi-Vitamin Two Daily

Enzymedica
A potentially better match in selected areas comes from vitamin D3, natural mixed vitamin E, beta-carotene, folate, and a broad vitamin-and-mineral base. Compared with the original beauty formula with 3,000 mcg of biotin but only 50 mg of collagen and 3 mg of horsetail, the natural vitamin E forms and broad coverage improve several nutrient-quality details, although enzyme, probiotic, ATP, and botanical entries lack measurable amounts.
73 Budget

Muti Vitamin Raspberry Flavor

Yum-V's Complete
A lower serving cost comes with vitamin D3, vitamin C, folic acid, biotin, and several B vitamins in an adult gummy. Compared with the original beauty formula with 3,000 mcg of biotin but only 50 mg of collagen and 3 mg of horsetail, it supplies basic adult nutrient coverage without extremely high biotin, although synthetic vitamin E, basic B-vitamin forms, and very little choline limit formulation depth.
78 Budget

Children's Chewable

Thompson
A lower serving cost comes with vitamin D3, natural-form vitamin E, beta-carotene, iron, and clearly named minerals. Compared with the original beauty formula with 3,000 mcg of biotin but only 50 mg of collagen and 3 mg of horsetail, the formula offers broad maintenance coverage with several useful forms, although it is designed for children and calcium, magnesium, and zinc are lightly dosed.
72 Budget

Flintstones Gummies + Immunity Support

Bayer
A lower serving cost comes with 90 mg of vitamin C with vitamin D, zinc, and a basic children’s vitamin profile. Compared with the original beauty formula with 3,000 mcg of biotin but only 50 mg of collagen and 3 mg of horsetail, the active formula is simple and avoids excessive amounts, although nearly all nutrient forms and the complete gummy-base ingredients are unspecified.
71 Value

Extra Strength Hair Skin & Nails

Spring Valley
A useful quality-to-cost balance comes from 5,000 mcg of D-biotin with 2,000 IU of vitamin D3, 90 mg of vitamin C, zinc, and 60 mg of collagen. Compared with the original beauty formula with 3,000 mcg of biotin but only 50 mg of collagen and 3 mg of horsetail, the beauty-support core is broader while staying relatively economical, although collagen, hyaluronic acid, horsetail, and oils are still modest and the high biotin amount can affect laboratory tests.
75 Value

Multi Adult Gummies

Nature Made
A useful quality-to-cost balance comes from vitamin D3, vitamin C, folic acid, biotin, and zinc in an adult gummy. Compared with the original beauty formula with 3,000 mcg of biotin but only 50 mg of collagen and 3 mg of horsetail, it provides inexpensive broad vitamin coverage in a simpler serving, although mineral coverage is thin and several nutrient forms are basic.
72 Value

One Daily Women's Adult Gummy

Equate
A useful quality-to-cost balance comes from vitamin D, vitamin E, folic acid, biotin, calcium, and zinc in a women’s adult gummy. Compared with the original beauty formula with 3,000 mcg of biotin but only 50 mg of collagen and 3 mg of horsetail, it provides broad basic coverage without the original formula’s very high biotin exposure, although many forms are unspecified and mineral amounts are light.
Report alternatives

Sources

Published studies used for the product analysis and the top-ranked studies for each ingredient and goal.

  1. Effect of Nicotinamide in Skin Cancer and Actinic Keratoses Chemoprophylaxis, and Adverse Effects Related to Nicotinamide: A Systematic Review and Meta-Analysis.
    Mainville L; Smilga AS; Fortin PR · Journal of cutaneous medicine and surgery · 2022
    Meta-analysis3,039 participants29 studies pooledSkin Health forNiacin
  2. Comorbid Conditions Associated with Alopecia Areata: A Systematic Review and Meta-analysis.
    Ly S; Manjaly P; Kamal K; Shields A; Wafae B; Afzal N; Drake L; Sanchez K; Gregoire S; Zhou G; Mita C; Mostaghimi A · American journal of clinical dermatology · 2023
    Meta-analysis72,791,864 participants102 studies pooledHair Health forVitamin D
  3. Topical adenosine increases thick hair ratio in Japanese men with androgenetic alopecia.
    Watanabe Y; Nagashima T; Hanzawa N; Ishino A; Nakazawa Y; Ogo M; Iwabuchi T; Tajima M · International journal of cosmetic science · 2016
    Randomized trial102 participantsHair Health forNiacin
  4. The Infatuation With Biotin Supplementation: Is There Truth Behind Its Rising Popularity? A Comparative Analysis of Clinical Efficacy versus Social Popularity.
    Soleymani T; Lo Sicco K; Shapiro J · Journal of drugs in dermatology : JDD · 2018
    Narrative reviewHair Health forBiotin
  5. Psoriasis treatment in difficult locations: scalp, nails, and intertriginous areas.
    Wozel G · Clinics in dermatology · 2009
    Narrative reviewNail Health forVitamin D
  6. Biotin for the treatment of nail disease: what is the evidence?
    Lipner SR; Scher RK · The Journal of dermatological treatment · 2018
    Narrative reviewNail Health forBiotin
  7. Nicotinamide for Skin-Cancer Chemoprevention in Transplant Recipients.
    Allen NC; Martin AJ; Snaidr VA; Eggins R; Chong AH; Fernandéz-Peñas P; Gin D; Sidhu S; Paddon VL; Banney LA; Lim A; Upjohn E; Schaider H; Ganhewa AD; Nguyen J; McKenzie CA; Prakash S; McLean C; Lochhead A; Ibbetson J; Dettrick A; Landgren A; Allnutt KJ; Allison C; Davenport RB; Mumford BP; Wong B; Stagg B; Tedman A; Gribbin H; Edwards HA; De Rosa N; Stewart T; Doolan BJ; Kok Y; Simpson K; Low ZM; Kovitwanichkanont T; Scolyer RA; Dhillon HM; Vardy JL; Chadban SJ; Bowen DG; Chen AC; Damian DL · The New England journal of medicine · 2023
    Randomized trial158 participantsSkin Health forNiacin
  8. Estimated serum vitamin D status, vitamin D intake, and risk of incident alopecia areata among US women.
    Thompson JM; Li T; Park MK; Qureshi AA; Cho E · Archives of dermatological research · 2017
    Cohort study55,929 participantsHair Health forVitamin D
  9. Vitamins A, B, C, and D: A Short Review for the Dermatologist.
    Coerdt KM; Goggins CA; Khachemoune A · Alternative therapies in health and medicine · 2021
    Narrative reviewHair Health forBiotin
  10. Recommendations for the definition, evaluation, and treatment of nail psoriasis in adult patients with no or mild skin psoriasis: A dermatologist and nail expert group consensus.
    Rigopoulos D; Baran R; Chiheb S; Daniel CR; Di Chiacchio N; Gregoriou S; Grover C; Haneke E; Iorizzo M; Pasch M; Piraccini BM; Rich P; Richert B; Rompoti N; Rubin AI; Singal A; Starace M; Tosti A; Triantafyllopoulou I; Zaiac M · Journal of the American Academy of Dermatology · 2019
    Guideline / consensusNail Health forVitamin D
  11. Treatment of brittle fingernails and onychoschizia with biotin: scanning electron microscopy.
    Colombo VE; Gerber F; Bronhofer M; Floersheim GL · Journal of the American Academy of Dermatology · 1991
    Other32 participantsNail Health forBiotin
  12. A pilot study evaluating the efficacy of topically applied niacin derivatives for treatment of female pattern alopecia.
    Draelos ZD; Jacobson EL; Kim H; Kim M; Jacobson MK · Journal of cosmetic dermatology · 2009
    Randomized trial60 participantsHair Health forNiacin
  13. Treatment with oral vitamin D alone, topical minoxidil, or combination of both in patients with female pattern hair loss: A comparative clinical and dermoscopic study.
    Hassan GFR; Sadoma MET; Elbatsh MM; Ibrahim ZA · Journal of cosmetic dermatology · 2022
    Non-randomized trial60 participantsHair Health forVitamin D
  14. A Foodborne Outbreak Traced to Niacin Overenrichment.
    Hudson PJ; Vogt RL · Journal of food protection · 2023
    Case-control study21 participantsSkin Health forNiacin
  15. Low serum biotinidase activity in children with valproic acid monotherapy.
    Schulpis KH; Karikas GA; Tjamouranis J; Regoutas S; Tsakiris S · Epilepsia · 2001
    Clinical trial125 participantsHair Health Skin Health forBiotin
  16. Vitamins for the Management of Nail Disease: A Literature Review.
    Curtis KL; Lipner SR · Skin appendage disorders · 2025
    Narrative reviewNail Health forVitamin D
  17. Vitamins and minerals: their role in nail health and disease.
    Scheinfeld N; Dahdah MJ; Scher R · Journal of drugs in dermatology : JDD · 2007
    Narrative reviewNail Health forBiotin Nail Health forZinc
  18. The clinical anti-aging effects of topical kinetin and niacinamide in Asians: a randomized, double-blind, placebo-controlled, split-face comparative trial.
    Chiu PC; Chan CC; Lin HM; Chiu HC · Journal of cosmetic dermatology · 2008
    Randomized trial52 participantsSkin Health forNiacin
  19. Increased prevalence of vitamin D deficiency in patients with alopecia areata: a systematic review and meta-analysis.
    Lee S; Kim BJ; Lee CH; Lee WS · Journal of the European Academy of Dermatology and Venereology : JEADV · 2018
    Meta-analysis2,039 participants14 studies pooledHair Health forVitamin D
  20. Nail psoriasis: clinical presentation and best practice recommendations.
    Edwards F; de Berker D · Drugs · 2010
    Narrative reviewNail Health forVitamin D
  21. Brittle nails: response to daily biotin supplementation.
    Hochman LG; Scher RK; Meyerson MS · Cutis · 1993
    Case series35 participantsNail Health forBiotin
  22. The Role of Sesbania grandiflora-Derived Biotin and Bambusa arundinacea-Derived Silica Extracts in Promoting Hair, Skin, and Nail Health: A Randomized, Double-Blind, Placebo-Controlled Clinical Study.
    Patel MN; Maheshvari J; Patel N · Cureus · 2025
    Randomized trial105 participantsHair Health Nail Health Skin Health forBiotin
  23. The effect of niacinamide on reducing cutaneous pigmentation and suppression of melanosome transfer.
    Hakozaki T; Minwalla L; Zhuang J; Chhoa M; Matsubara A; Miyamoto K; Greatens A; Hillebrand GG; Bissett DL; Boissy RE · The British journal of dermatology · 2002
    Randomized trial138 participantsSkin Health forNiacin
  24. Intralesional vitamin D3 in treatment of alopecia areata: A randomized controlled clinical trial.
    Rashad AF; Elgamal E; Fouda I · Journal of cosmetic dermatology · 2022
    Randomized trial60 participantsHair Health forVitamin D
  25. Nail involvement in psoriatic arthritis.
    Sobolewski P; Walecka I; Dopytalska K · Reumatologia · 2019
    Narrative reviewNail Health forVitamin D
  26. Nail Supplements: When, How, and Why?
    Zaraa I; Richert B · Skin appendage disorders · 2026
    Narrative reviewNail Health forBiotin Nail Health forCollagen
  27. Niacinamide: A B vitamin that improves aging facial skin appearance.
    Bissett DL; Oblong JE; Berge CA · Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.] · 2005
    Randomized trial50 participantsSkin Health forNiacin
  28. 25-hydroxyvitamin D status in patients with alopecia areata.
    Erpolat S; Sarifakioglu E; Ayyildiz A · Postepy dermatologii i alergologii · 2022
    Case-control study73 participantsHair Health forVitamin D
  29. Brittle nails.
    Iorizzo M; Pazzaglia M; M Piraccini B; Tullo S; Tosti A · Journal of cosmetic dermatology · 2009
    Narrative reviewNail Health forBiotin
  30. Nicotinamide for Skin Cancer Chemoprevention.
    Breglio KF; Knox KM; Hwang J; Weiss R; Maas K; Zhang S; Yao L; Madden C; Xu Y; Hartman RI; Wheless L · JAMA dermatology · 2025
    Cohort study33,822 participantsSkin Health forNiacin
  31. Association Between Trichoscopic Features and Serum Hormone Levels and Vitamin D Concentration in Patients with Androgenetic Alopecia in Eastern China: A Cross-Sectional Study.
    Chen Q; Tao Q; Zhu Q; Zhu J; Du X · Clinical, cosmetic and investigational dermatology · 2023
    Cross-sectional study310 participantsHair Health forVitamin D
  32. Niacin intake and risk of skin cancer in US women and men.
    Park SM; Li T; Wu S; Li WQ; Weinstock M; Qureshi AA; Cho E · International journal of cancer · 2017
    Cohort study114,116 participantsSkin Health forNiacin
  33. Topical calcipotriol vs narrowband ultraviolet B in treatment of alopecia areata: a randomized-controlled trial.
    El Taieb MA; Hegazy EM; Ibrahim HM; Osman AB; Abualhamd M · Archives of dermatological research · 2020
    Randomized trial60 participantsHair Health forVitamin D
  34. Evaluation of anti-wrinkle effects of a novel cosmetic containing niacinamide.
    Kawada A; Konishi N; Oiso N; Kawara S; Date A · The Journal of dermatology · 2008
    Randomized trial30 participantsSkin Health forNiacin
  35. Biomarkers in alopecia Areata: A systematic review and meta-analysis.
    Zaaroura H; Gilding AJ; Sibbald C · Autoimmunity reviews · 2023
    Meta-analysis91 studies pooledHair Health forVitamin D
  36. Chemoprevention of keratinocyte carcinomas and actinic keratoses in adults who were immunocompetent: a systematic review.
    Susanto A; Morgan E; Lindsay D; Collins LG · Clinical and experimental dermatology · 2026
    Systematic review7,355 participants11 studies pooledSkin Health forNiacin
  37. Vitamin D and its Analogs in Treatment of Mild to Moderate Alopecia Areata: Systematic Review and Meta-Analysis.
    Alsaati AA; Kaliyadan F; Alsaadoun D; Alzakry LM; Alzabadin RA; Hakami TH; Rubaian NFB · Indian dermatology online journal · 2025
    Meta-analysisHair Health forVitamin D
  38. A double-blind, placebo-controlled, randomised, clinical study on the effectiveness of collagen peptide on osteoarthritis.
    Kumar S; Sugihara F; Suzuki K; Inoue N; Venkateswarathirukumara S · Journal of the science of food and agriculture · 2015
    Randomized trialGeneral Health forCollagen
  39. Efficacy and safety of native type II collagen in modulating knee osteoarthritis symptoms: a randomised, double-blind, placebo-controlled trial.
    Luo C; Su W; Song Y; Srivastava S · Journal of experimental orthopaedics · 2023
    Randomized trial101 participantsGeneral Health forCollagen
  40. Healing Process, Pain, and Health-Related Quality of Life in Patients with Venous Leg Ulcers Treated with Fish Collagen Gel: A 12-Week Randomized Single-Center Study.
    Mościcka P; Cwajda-Białasik J; Szewczyk MT; Jawień A · International journal of environmental research and public health · 2022
    Randomized trial100 participantsGeneral Health forCollagen
  41. Efficacy and Safety of Dietary Undenatured Type II Collagen on Joint and Motor Function in Healthy Volunteers: A Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Study.
    Shiojima Y; Takahashi M; Takahashi R; Maruyama K; Moriyama H; Bagchi D; Bagchi M; Akanuma M · Journal of the American Nutrition Association · 2023
    Randomized trial64 participantsGeneral Health forCollagen
  42. The use of a collagen matrix in hard-to-heal venous leg ulcers.
    Romanelli M; Mulder G; Paggi B; Macchia M; Panduri S; Dini V · Journal of wound care · 2016
    Randomized trial40 participantsGeneral Health forCollagen
  43. Intakes of Folate, Vitamin B6, and Vitamin B12 in Relation to All-Cause and Cause-Specific Mortality: A National Population-Based Cohort.
    Bo Y; Xu H; Zhang H; Zhang J; Wan Z; Zhao X; Yu Z · Nutrients · 2022
    Cohort study55,569 participantsGeneral Health forFolate
  44. The responsiveness of plasma homocysteine to small increases in dietary folic acid: a primary care study.
    Schorah CJ; Devitt H; Lucock M; Dowell AC · European journal of clinical nutrition · 1998
    Randomized trial119 participantsGeneral Health forFolate
  45. Associations of Serum Folate and Homocysteine Concentrations with All-Cause, Cardiovascular Disease, and Cancer Mortality in Men and Women in Korea: the Cardiovascular Disease Association Study.
    Song S; Song BM; Park HY · The Journal of nutrition · 2023
    Cohort study21,260 participantsGeneral Health forFolate
  46. The concept of folic acid supplementation and its role in prevention of neural tube defect among pregnant women: PRISMA.
    Seyoum Tola F · Medicine · 2024
    Systematic reviewGeneral Health forFolate
  47. Systematic review of adverse health outcomes associated with high serum or red blood cell folate concentrations.
    Colapinto CK; O'Connor DL; Sampson M; Williams B; Tremblay MS · Journal of public health (Oxford, England) · 2017
    Systematic review71,847 participants46 studies pooledGeneral Health forFolate
  48. Perioperative systemic magnesium to minimize postoperative pain: a meta-analysis of randomized controlled trials.
    De Oliveira GS; Castro-Alves LJ; Khan JH; McCarthy RJ · Anesthesiology · 2013
    Meta-analysis1,257 participants20 studies pooledGeneral Health forMagnesium
  49. Long-term outcome after intravenous magnesium sulphate in suspected acute myocardial infarction: the second Leicester Intravenous Magnesium Intervention Trial (LIMIT-2).
    Woods KL; Fletcher S · Lancet (London, England) · 1994
    Randomized trial2,316 participantsGeneral Health forMagnesium
  50. Association of magnesium sulfate use with mortality in critically ill patients with sepsis: a retrospective propensity score-matched cohort study.
    Gu WJ; Duan XJ; Liu XZ; Cen Y; Tao LY; Lyu J; Yin HY · British journal of anaesthesia · 2023
    Cohort study10,999 participantsGeneral Health forMagnesium
  51. Hypomagnesemia and Mortality in Incident Hemodialysis Patients.
    Li L; Streja E; Rhee CM; Mehrotra R; Soohoo M; Brunelli SM; Kovesdy CP; Kalantar-Zadeh K · American journal of kidney diseases : the official journal of the National Kidney Foundation · 2016
    Cohort study9,359 participantsGeneral Health forMagnesium
  52. The effects of magnesium supplementation on abnormal uterine bleeding, alopecia, quality of life, and acne in women with polycystic ovary syndrome: a randomized clinical trial.
    Jaripur M; Ghasemi-Tehrani H; Askari G; Gholizadeh-Moghaddam M; Clark CCT; Rouhani MH · Reproductive biology and endocrinology : RB&E · 2022
    Randomized trial64 participantsGeneral Health forMagnesium
  53. Dietary intake and blood concentrations of antioxidants and the risk of cardiovascular disease, total cancer, and all-cause mortality: a systematic review and dose-response meta-analysis of prospective studies.
    Aune D; Keum N; Giovannucci E; Fadnes LT; Boffetta P; Greenwood DC; Tonstad S; Vatten LJ; Riboli E; Norat T · The American journal of clinical nutrition · 2019
    Meta-analysis69 studies pooledGeneral Health forVitamin C
  54. Scientific Opinion on the substantiation of a health claim related to vitamin C and increasing non haem iron absorption pursuant to Article 14 of Regulation (EC) No 1924/2006.
    EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) · EFSA journal. European Food Safety Authority · 2026
    Guideline / consensusGeneral Health forVitamin C
  55. Vitamin C Depletion and All-Cause Mortality in Renal Transplant Recipients.
    Sotomayor CG; Eisenga MF; Gomes Neto AW; Ozyilmaz A; Gans ROB; Jong WHA; Zelle DM; Berger SP; Gaillard CAJM; Navis GJ; Bakker SJ · Nutrients · 2018
    Cohort study598 participantsGeneral Health forVitamin C
  56. Associations of Serum Biomarkers of Fruit and Vegetable Intake With the Risk of Cause-Specific Mortality and All-Cause Mortality: A National Prospective Cohort Study.
    Pu L; Zhang R; Wang X; Zhao T; Sun H; Han L · Frontiers in nutrition · 2022
    Cohort study12,530 participantsGeneral Health forVitamin C
  57. Relation between plasma ascorbic acid and mortality in men and women in EPIC-Norfolk prospective study: a prospective population study. European Prospective Investigation into Cancer and Nutrition.
    Khaw KT; Bingham S; Welch A; Luben R; Wareham N; Oakes S; Day N · Lancet (London, England) · 2001
    Cohort study19,496 participantsGeneral Health forVitamin C
  58. Vitamin D supplementation for prevention of mortality in adults.
    Bjelakovic G; Gluud LL; Nikolova D; Whitfield K; Wetterslev J; Simonetti RG; Bjelakovic M; Gluud C · The Cochrane database of systematic reviews · 2014
    Meta-analysis95,286 participants159 studies pooledGeneral Health forVitamin D
  59. Effect of vitamin D on gastrointestinal symptoms and health-related quality of life in irritable bowel syndrome patients: a randomized double-blind clinical trial.
    Abbasnezhad A; Amani R; Hajiani E; Alavinejad P; Cheraghian B; Ghadiri A · Neurogastroenterology and motility · 2018
    Randomized trial90 participantsGeneral Health forVitamin D
  60. The impact of vitamin D administration on mortality in COVID-19 patients: a systematic review and meta-analysis of randomized controlled trials.
    Kow CS; Ramachandram DS; Hasan SS; Wong Z; Thiruchelvam K · Inflammopharmacology · 2024
    Meta-analysis2,495 participants19 studies pooledGeneral Health forVitamin D
  61. Vitamin D Status and Mortality: A Systematic Review of Observational Studies.
    Heath AK; Kim IY; Hodge AM; English DR; Muller DC · International journal of environmental research and public health · 2019
    Systematic review84 studies pooledGeneral Health forVitamin D
  62. Meta-analysis of long-term vitamin D supplementation on overall mortality.
    Zheng Y; Zhu J; Zhou M; Cui L; Yao W; Liu Y · PloS one · 2014
    Meta-analysis42 studies pooledGeneral Health forVitamin D
  63. Effectiveness of sodium bicarbonate and zinc chloride mouthwashes in the treatment of oral mucositis and quality of life in patients with cancer under chemotherapy.
    Mohammadi F; Oshvandi K; Kamallan SR; Khazaei S; Ranjbar H; Ahmadi-Motamayel F; Gillespie M; Jenabi E; Vafaei SY · Nursing open · 2022
    Randomized trial144 participantsGeneral Health forZinc
  64. Zinc supplementation in young children with acute diarrhea in India.
    Sazawal S; Black RE; Bhan MK; Bhandari N; Sinha A; Jalla S · The New England journal of medicine · 1995
    Randomized trial937 participantsGeneral Health forZinc
  65. Associations of mortality with ocular disorders and an intervention of high-dose antioxidants and zinc in the Age-Related Eye Disease Study: AREDS Report No. 13.
    Clemons TE; Kurinij N; Sperduto RD; AREDS Research Group · Archives of ophthalmology (Chicago, Ill. : 1960) · 2004
    Randomized trial4,753 participantsGeneral Health forZinc
  66. Effects of zinc and probiotic co-supplementation on inflammation, gastrointestinal symptoms, quality of life, and mood in irritable bowel syndrome patients.
    Rezazadegan M; Soheilipour M; Amani R · Scientific reports · 2026
    Randomized trial84 participantsGeneral Health forZinc
  67. Effect of zinc sulfate supplementation on premenstrual syndrome and health-related quality of life: Clinical randomized controlled trial.
    Siahbazi S; Behboudi-Gandevani S; Moghaddam-Banaem L; Montazeri A · The journal of obstetrics and gynaecology research · 2018
    Randomized trial142 participantsGeneral Health forZinc
  68. Low-Molecular-Weight Collagen Peptide Supplementation Improves Cellulite Severity, Skin Elasticity, and Hair Shaft Diameter: A Clinical Study with Pharmacokinetic Evaluation.
    Hwang S; Won J; Kim S; Kang W; Park M · Journal of medicinal food · 2026
    Randomized trial114 participantsHair Health forCollagen
  69. Calcium and Vitamin D Supplementation with and Without Collagen on Bone Density and Skin Elasticity in Menopausal Women-A Randomized Controlled Study.
    Duangjai A; Srivilai J; Nangola S; Amornlerdpison D · Clinics and practice · 2025
    Randomized trialHair Health forCollagen
  70. Dietary Collagen Supplementation as a Strategy for Skin Health: A Narrative Review of Clinical Effects on Skin, Hair, Nails, and Wound Healing.
    Biełach-Bazyluk A; Jurga M; Flisiak I; Zbroch E · Nutrients · 2026
    Narrative reviewHair Health forCollagen
  71. Topical tretinoin for hair growth promotion.
    Bazzano GS; Terezakis N; Galen W · Journal of the American Academy of Dermatology · 1986
    Non-randomized trial56 participantsHair Health forVitamin A
  72. A review of isotretinoin in the treatment of frontal fibrosing alopecia.
    Shahpar A; Nezhad NZ; Sahaf AS; Ahramiyanpour N · Journal of cosmetic dermatology · 2024
    Systematic review232 participants15 studies pooledHair Health forVitamin A
  73. Efficacy of Isotretinoin and Acitretin in Treatment of Frontal Fibrosing Alopecia: Retrospective Analysis of 54 Cases.
    Rakowska A; Gradzińska A; Olszewska M; Rudnicka L · Journal of drugs in dermatology : JDD · 2018
    Cohort study54 participantsHair Health forVitamin A
  74. Systemic Treatments for Lichen Planopilaris and Frontal Fibrosing Alopecia: A Retrospective Study of 315 Patients.
    Willaert M; Van Dongen T; Dikrama P; Nijsten T; Hijnen D; Waalboer-Spuij R · Acta dermato-venereologica · 2025
    Cohort study315 participantsHair Health forVitamin A
  75. Tretinoin enhances minoxidil response in androgenetic alopecia patients by upregulating follicular sulfotransferase enzymes.
    Sharma A; Goren A; Dhurat R; Agrawal S; Sinclair R; Trüeb RM; Vañó-Galván S; Chen G; Tan Y; Kovacevic M; Situm M; McCoy J · Dermatologic therapy · 2020
    Single-arm trialHair Health forVitamin A
  76. Management of hair loss associated with endocrine therapy in patients with breast cancer: an overview.
    Karatas F; Sahin S; Sever AR; Altundag K · SpringerPlus · 2016
    Narrative reviewHair Health forVitamin C
  77. Elucidating causal relationships of diet-derived circulating antioxidants and the risk of non-scarring alopecia: A Mendelian randomization study.
    Ba Y; Shen L; Peng X; Zhang Y; Wang J · Medicine · 2024
    Methods validation study201,019 participantsHair Health forVitamin C
  78. Alterations of plasma antioxidants and mitochondrial DNA mutation in hair follicles of smokers.
    Liu CS; Chen HW; Lii CK; Tsai CS; Kuo CL; Wei YH · Environmental and molecular mutagenesis · 2002
    Observational studyHair Health forVitamin C
  79. Removal of synthetic hair dye using formamidine sulfinic acid and other sulfinate precursors.
    Hawkes JA; Lewis DM; Mama J; Murray J · International journal of cosmetic science · 2026
    Methods validation studyHair Health forVitamin C
  80. A Zinc Sulphate-Resistant Acrodermatitis Enteropathica Patient with a Novel Mutation in SLC39A4 Gene.
    Kilic M; Taskesen M; Coskun T; Gürakan F; Tokatli A; Sivri HS; Dursun A; Schmitt S; Küry S · JIMD reports · 2013
    Case reportHair Health forVitamin C
  81. Serum 25 hydroxyvitamin D in non-scarring alopecia: A systematic review and meta-analysis.
    Chen Y; Dong X; Wang Y; Li Y; Xiong L; Li L · Journal of cosmetic dermatology · 2024
    Meta-analysis10,670 participants23 studies pooledHair Health forVitamin D
  82. The effects of minoxidil, 1% pyrithione zinc and a combination of both on hair density: a randomized controlled trial.
    Berger RS; Fu JL; Smiles KA; Turner CB; Schnell BM; Werchowski KM; Lammers KM · The British journal of dermatology · 2003
    Randomized trial200 participantsHair Health forZinc
  83. Incubatory environment of the scalp impacts pre-emergent hair to affect post-emergent hair cuticle integrity.
    Schwartz JR; Henry JP; Kerr KM; Flagler MJ; Page SH; Redman-Furey N · Journal of cosmetic dermatology · 2018
    Randomized trialHair Health forZinc
  84. A comparison of hair quality and cosmetic acceptance following the use of two anti-dandruff shampoos.
    Draelos ZD; Kenneally DC; Hodges LT; Billhimer W; Copas M; Margraf C · The journal of investigative dermatology. Symposium proceedings · 2006
    Randomized trial40 participantsHair Health forZinc
  85. BMI and levels of zinc, copper in hair, serum and urine of Turkish male patients with androgenetic alopecia.
    Ozturk P; Kurutas E; Ataseven A; Dokur N; Gumusalan Y; Gorur A; Tamer L; Inaloz S · Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements (GMS) · 2015
    Case-control study216 participantsHair Health forZinc
  86. Analysis of serum zinc and copper concentrations in hair loss.
    Kil MS; Kim CW; Kim SS · Annals of dermatology · 2013
    Case-control study342 participantsHair Health forZinc
  87. Depressed immune response to tetanus in children with vitamin A deficiency.
    Semba RD; Muhilal; Scott AL; Natadisastra G; Wirasasmita S; Mele L; Ridwan E; West KP; Sommer A · The Journal of nutrition · 1992
    Randomized trial236 participantsImmunity forVitamin A
  88. Impact of a single megadose of vitamin A at delivery on breastmilk of mothers and morbidity of their infants.
    Roy SK; Islam A; Molla A; Akramuzzaman SM; Jahan F; Fuchs G · European journal of clinical nutrition · 1997
    Randomized trial50 participantsImmunity forVitamin A
  89. Vitamin A supplementation reduces measles morbidity in young African children: a randomized, placebo-controlled, double-blind trial.
    Coutsoudis A; Broughton M; Coovadia HM · The American journal of clinical nutrition · 1991
    Randomized trial60 participantsImmunity forVitamin A
  90. Vitamin A supplementation enhances specific IgG antibody levels and total lymphocyte numbers while improving morbidity in measles.
    Coutsoudis A; Kiepiela P; Coovadia HM; Broughton M · The Pediatric infectious disease journal · 1992
    Randomized trial60 participantsImmunity forVitamin A
  91. Vitamin A supplementation reduces the monocyte chemoattractant protein-1 intestinal immune response of Mexican children.
    Long KZ; Santos JI; Estrada Garcia T; Haas M; Firestone M; Bhagwat J; Dupont HL; Hertzmark E; Rosado JL; Nanthakumar NN · The Journal of nutrition · 2006
    Randomized trial127 participantsImmunity forVitamin A
  92. Vitamin C and contribution to the normal function of the immune system: evaluation of a health claim pursuant to Article 14 of Regulation (EC) No 1924/2006.
    EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) · EFSA journal. European Food Safety Authority · 2026
    Guideline / consensusImmunity forVitamin C
  93. Therapeutic effects of high-dose vitamin C supplementation in patients with COVID-19: a meta-analysis.
    Sun L; Zhao JH; Fan WY; Feng B; Liu WW; Chen RQ; Ban C; Dang AG; Wang M; Luo KT; Zhou GY; Yu FF; Ba Y · Nutrition reviews · 2024
    Meta-analysis2,334 participants14 studies pooledImmunity forVitamin C
  94. Effect of micronutrient supplements on influenza and other respiratory tract infections among adults: a systematic review and meta-analysis.
    Abioye AI; Bromage S; Fawzi W · BMJ global health · 2021
    Meta-analysisImmunity forVitamin C
  95. New evidence for antioxidant properties of vitamin C.
    Vojdani A; Bazargan M; Vojdani E; Wright J · Cancer detection and prevention · 2001
    Randomized trial20 participantsImmunity forVitamin C
  96. Enhanced Vitamin C Delivery: A Systematic Literature Review Assessing the Efficacy and Safety of Alternative Supplement Forms in Healthy Adults.
    Calder PC; Kreider RB; McKay DL · Nutrients · 2025
    Systematic review13 studies pooledImmunity forVitamin C
  97. Vitamin D supplementation to prevent acute respiratory infections: individual participant data meta-analysis.
    Martineau AR; Jolliffe DA; Greenberg L; Aloia JF; Bergman P; Dubnov-Raz G; Esposito S; Ganmaa D; Ginde AA; Goodall EC; Grant CC; Janssens W; Jensen ME; Kerley CP; Laaksi I; Manaseki-Holland S; Mauger D; Murdoch DR; Neale R; Rees JR; Simpson S; Stelmach I; Trilok Kumar G; Urashima M; Camargo CA; Griffiths CJ; Hooper RL · Health technology assessment (Winchester, England) · 2020
    Meta-analysis11,321 participants25 studies pooledImmunity forVitamin D
  98. Association Between Vitamin D and Influenza: Meta-Analysis and Systematic Review of Randomized Controlled Trials.
    Zhu Z; Zhu X; Gu L; Zhan Y; Chen L; Li X · Frontiers in nutrition · 2022
    Meta-analysis4,859 participants10 studies pooledImmunity forVitamin D
  99. Vitamin D3 and deconvoluting a rash.
    Ernst MK; Evans ST; Techner JM; Rothbaum RM; Christensen LF; Onay UV; Biyashev D; Demczuk MM; Nguyen CV; Honda KS; McCormick TS; Tsoi LC; Gudjonsson JE; Cooper KD; Lu KQ · JCI insight · 2023
    Randomized trial28 participantsImmunity forVitamin D
  100. Effect of vitamin D3 supplementation on cellular immunity and inflammatory markers in COVID-19 patients admitted to the ICU.
    Bychinin MV; Klypa TV; Mandel IA; Yusubalieva GM; Baklaushev VP; Kolyshkina NA; Troitsky AV · Scientific reports · 2022
    Randomized trial110 participantsImmunity forVitamin D
  101. Current opinion on the role of vitamin D supplementation in respiratory infections and asthma/COPD exacerbations: A need to establish publication guidelines for overcoming the unpublished data.
    Anitua E; Tierno R; Alkhraisat MH · Clinical nutrition (Edinburgh, Scotland) · 2022
    Meta-analysis50,554 participants65 studies pooledImmunity forVitamin D
  102. Nutrient supplementation for prevention of viral respiratory tract infections in healthy subjects: A systematic review and meta-analysis.
    Vlieg-Boerstra B; de Jong N; Meyer R; Agostoni C; De Cosmi V; Grimshaw K; Milani GP; Muraro A; Oude Elberink H; Pali-Schöll I; Roduit C; Sasaki M; Skypala I; Sokolowska M; van Splunter M; Untersmayr E; Venter C; O'Mahony L; Nwaru BI · Allergy · 2022
    Meta-analysis199,055 participants115 studies pooledImmunity forZinc
  103. Zinc supplementation reduces the incidence of acute lower respiratory infections in infants and preschool children: a double-blind, controlled trial.
    Sazawal S; Black RE; Jalla S; Mazumdar S; Sinha A; Bhan MK · Pediatrics · 1998
    Randomized trial609 participantsImmunity forZinc
  104. A randomized controlled trial of zinc supplementation in the treatment of acute respiratory tract infection in Thai children.
    Rerksuppaphol S; Rerksuppaphol L · Pediatric reports · 2020
    Randomized trial64 participantsImmunity forZinc
  105. The effect of zinc and vitamin A supplementation on immune response in an older population.
    Fortes C; Forastiere F; Agabiti N; Fano V; Pacifici R; Virgili F; Piras G; Guidi L; Bartoloni C; Tricerri A; Zuccaro P; Ebrahim S; Perucci CA · Journal of the American Geriatrics Society · 1998
    Randomized trial136 participantsImmunity forZinc
  106. The role of specific nutrients in preventing immune system and blood cell disorders: an umbrella review.
    Vecchietti A; Strano P; Minutolo G; Grieco V; Cappuccio G; Granvillano G; Confalonieri L; Briganti GL; Raso E; Chimienti M; Pellegrini M; Mercogliano M; Spatari G; Lugli C; Urbano T; Lorenzon A · Journal of preventive medicine and hygiene · 2026
    Systematic review13 studies pooledImmunity forZinc
  107. Treatment of brittle nail with a hydroxypropyl chitosan-based lacquer, alone or in combination with oral biotin: A randomized, assessor-blinded trial.
    Chiavetta A; Mazzurco S; Secolo MP; Tomarchio G; Milani M · Dermatologic therapy · 2020
    Randomized trial50 participantsNail Health forBiotin
  108. Oral supplementation with specific bioactive collagen peptides improves nail growth and reduces symptoms of brittle nails.
    Hexsel D; Zague V; Schunck M; Siega C; Camozzato FO; Oesser S · Journal of cosmetic dermatology · 2018
    Single-arm trial25 participantsNail Health forCollagen
  109. Influence of collagen peptide supplementation on visible signs of skin and nail health and -aging in an East Asian population: A double blind, randomized, placebo-controlled trial.
    Vleminckx S; Virgilio N; Asserin J; Prawitt J; Silva CIF · Journal of cosmetic dermatology · 2024
    Randomized trial85 participantsNail Health forCollagen
  110. Expanding the COL7A1 mutation database: novel and recurrent mutations and unusual genotype-phenotype constellations in 41 patients with dystrophic epidermolysis bullosa.
    Kern JS; Kohlhase J; Bruckner-Tuderman L; Has C · The Journal of investigative dermatology · 2006
    Observational study41 participantsNail Health forCollagen
  111. Vitamin C Deficiency in Inflammatory Bowel Disease: The Forgotten Micronutrient.
    Dunleavy KA; Ungaro RC; Manning L; Gold S; Novak J; Colombel JF · Crohn's & colitis 360 · 2023
    Other20 participantsNail Health forVitamin C
  112. Evaluation of biophysical skin parameters and hair changes in patients with acne vulgaris treated with isotretinoin, and the effect of biotin use on these parameters.
    Aksac SE; Bilgili SG; Yavuz GO; Yavuz IH; Aksac M; Karadag AS · International journal of dermatology · 2021
    Non-randomized trial60 participantsSkin Health forBiotin
  113. Generalized seborrhoeic dermatitis. Clinical and therapeutic data of 25 patients.
    Messaritakis J; Kattamis C; Karabula C; Matsaniotis N · Archives of disease in childhood · 1976
    Non-randomized trial25 participantsSkin Health forBiotin
  114. Holocarboxylase synthetase deficiency: novel clinical and molecular findings.
    Tammachote R; Janklat S; Tongkobpetch S; Suphapeetiporn K; Shotelersuk V · Clinical genetics · 2010
    Case series4 participantsSkin Health forBiotin
  115. Exploring the Impact of Hydrolyzed Collagen Oral Supplementation on Skin Rejuvenation: A Systematic Review and Meta-Analysis.
    Dewi DAR; Arimuko A; Norawati L; Yenny SW; Setiasih NL; Perdiyana A; Arkania N; Nadhira F; Wiliantari N · Cureus · 2024
    Meta-analysis967 participants14 studies pooledSkin Health forCollagen
  116. Effects of collagen-based supplements on skin's hydration and elasticity: A systematic review and meta-analysis.
    Danessa G; Notario D; Regina R · Indian journal of dermatology, venereology and leprology · 2025
    Meta-analysis646 participants10 studies pooledSkin Health forCollagen
  117. Oral intake of collagen peptide NS improves hydration, elasticity, desquamation, and wrinkling in human skin: a randomized, double-blinded, placebo-controlled study.
    Lee M; Kim E; Ahn H; Son S; Lee H · Food & function · 2023
    Randomized trial100 participantsSkin Health forCollagen
  118. Oral Intake of Low-Molecular-Weight Collagen Peptide Improves Hydration, Elasticity, and Wrinkling in Human Skin: A Randomized, Double-Blind, Placebo-Controlled Study.
    Kim DU; Chung HC; Choi J; Sakai Y; Lee BY · Nutrients · 2018
    Randomized trial64 participantsSkin Health forCollagen
  119. Effects of hydrolyzed collagen supplementation on skin aging: a systematic review and meta-analysis.
    de Miranda RB; Weimer P; Rossi RC · International journal of dermatology · 2021
    Meta-analysis1,125 participants19 studies pooledSkin Health forCollagen
  120. Efficacy and Tolerability of Topical 0.1% Stabilized Bioactive Retinol for Photoaging: A Vehicle-Controlled Integrated Analysis.
    Farris P; Berson D; Bhatia N; Goldberg D; Lain E; Mariwalla K; Zeichner J; Miller D; McGuire T; Kizoulis M · Journal of drugs in dermatology : JDD · 2024
    Meta-analysis471 participants6 studies pooledSkin Health forVitamin A
  121. Tensile properties and contours of aging facial skin. A controlled double-blind comparative study of the effects of retinol, melibiose-lactose and their association.
    Piérard-Franchimont C; Castelli D; Cromphaut IV; Bertin C; Ries G; Cauwenbergh G; Piérard GE · Skin research and technology : official journal of International Society for Bioengineering and the Skin (ISBS) [and] International Society for Digital Imaging of Skin (ISDIS) [and] International Society for Skin Imaging (ISSI) · 2016
    Randomized trial120 participantsSkin Health forVitamin A
  122. Antiaging action of retinol: from molecular to clinical.
    Bellemère G; Stamatas GN; Bruère V; Bertin C; Issachar N; Oddos T · Skin pharmacology and physiology · 2009
    Randomized trial48 participantsSkin Health forVitamin A
  123. An Updated Review of Topical Tretinoin in Dermatology: From Acne and Photoaging to Skin Cancer.
    Balado-Simó P; Morgado-Carrasco D; Gómez-Armayones S; López-Ferrer A; Barco D; Ferrándiz-Pulido C; Podlipnik S · Journal of clinical medicine · 2025
    Narrative reviewSkin Health forVitamin A
  124. Novel Cyclized Hexapeptide-9 Outperforms Retinol Against Skin Aging: A Randomized, Double-Blinded, Active- and Vehicle-Controlled Clinical Trial.
    Chang H; Tao K; Yang Y; Wang Y; Ge M; Wang X; Tang S; Yu H · Journal of cosmetic dermatology · 2025
    Randomized trialSkin Health forVitamin A
  125. Evaluation of the anti-wrinkle effect of an ascorbic acid-loaded dissolving microneedle patch via a double-blind, placebo-controlled clinical study.
    Lee C; Yang H; Kim S; Kim M; Kang H; Kim N; An S; Koh J; Jung H · International journal of cosmetic science · 2017
    Randomized trial23 participantsSkin Health forVitamin C
  126. Comparative Study on the Outcome of Periorbital Wrinkles Treated with Laser-Assisted Delivery of Vitamin C or Vitamin C Plus Growth Factors: A Randomized, Double-blind, Clinical Trial.
    Machado BHB; Frame J; Zhang J; Najlah M · Aesthetic plastic surgery · 2021
    Randomized trial149 participantsSkin Health forVitamin C
  127. Randomized trial of topical ascorbic acid in DMSO versus imiquimod for the treatment of basal cell carcinoma.
    Burke B; Bailie JE · Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie · 2022
    Randomized trial25 participantsSkin Health forVitamin C
  128. Vitamin C improves healing of foot ulcers: a randomised, double-blind, placebo-controlled trial.
    Gunton JE; Girgis CM; Lau T; Vicaretti M; Begg L; Flood V · The British journal of nutrition · 2022
    Randomized trial16 participantsSkin Health forVitamin C
  129. Dietary nutrient intakes and skin-aging appearance among middle-aged American women.
    Cosgrove MC; Franco OH; Granger SP; Murray PG; Mayes AE · The American journal of clinical nutrition · 2007
    Cross-sectional study4,025 participantsSkin Health forVitamin C
  130. Randomized controlled trial using vitamins E and D supplementation in atopic dermatitis.
    Javanbakht MH; Keshavarz SA; Djalali M; Siassi F; Eshraghian MR; Firooz A; Seirafi H; Ehsani AH; Chamari M; Mirshafiey A · The Journal of dermatological treatment · 2011
    Randomized trial45 participantsSkin Health forVitamin E
  131. Serum vitamin E levels and chronic inflammatory skin diseases: A systematic review and meta-analysis.
    Liu X; Yang G; Luo M; Lan Q; Shi X; Deng H; Wang N; Xu X; Zhang C · PloS one · 2022
    Meta-analysis20 studies pooledSkin Health forVitamin E
  132. Evidence-Based Nutritional Interventions in Wound Care.
    Saeg F; Orazi R; Bowers GM; Janis JE · Plastic and reconstructive surgery · 2021
    Systematic review2,339 participants36 studies pooledSkin Health forVitamin E Skin Health forZinc
  133. Effects of tocotrienol on aging skin: A systematic review.
    Ghazali NI; Mohd Rais RZ; Makpol S; Chin KY; Yap WN; Goon JA · Frontiers in pharmacology · 2022
    Systematic reviewSkin Health forVitamin E
  134. Carotenoids and carotenoids plus vitamin E protect against ultraviolet light-induced erythema in humans.
    Stahl W; Heinrich U; Jungmann H; Sies H; Tronnier H · The American journal of clinical nutrition · 2000
    Randomized trialSkin Health forVitamin E
  135. Sex-related differences in response to zinc pyrithione shampoo vs. non-anti-dandruff shampoo.
    Collins LZ; Baines FL; Matheson JR; Turner GA; Diao Y; Li Y; Pi Y · International journal of cosmetic science · 2019
    Meta-analysis2,088 participants20 studies pooledSkin Health forZinc
  136. Maintenance of an Acidic Skin Surface with a Novel Zinc Lactobionate Emollient Preparation Improves Skin Barrier Function in Patients with Atopic Dermatitis.
    Andrew PV; Pinnock A; Poyner A; Brown K; Chittock J; Kay LJ; Cork MJ; Danby SG · Dermatology and therapy · 2024
    Cohort study23 participantsSkin Health forZinc
  137. Spatial expression of metallothionein, matrix metalloproteinase-1 and Ki-67 in human epidermal wounds treated with zinc and determined by quantitative immunohistochemistry: A randomised double-blind trial.
    Ågren MS; Chafranska L; Eriksen JO; Forman JL; Bjerrum MJ; Schjerling P; Larsen HF; Cottarelli E; Jorgensen LN; Gjerdrum LMR · European journal of cell biology · 2021
    Randomized trial30 participantsSkin Health forZinc
  138. A pilot trial using topical regular crystalline insulin vs. aqueous zinc solution for uncomplicated cutaneous wound healing: Impact on quality of life.
    Attia EA; Belal DM; El Samahy MH; El Hamamsy MH · Wound repair and regeneration : official publication of the Wound Healing Society [and] the European Tissue Repair Society · 2014
    Randomized trial90 participantsSkin Health forZinc