ビタミンB12 ： 栄養不足による脱毛症
F合計8,355名の参加者を対象とした20件の研究に基づく。研究間で結果にばらつきが見られる。
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F
結論
Research shows mixed results for vitamin B12 and hair loss — while deficiency may contribute to hair thinning, supplementation is unlikely to help unless you have a confirmed B12 deficiency.
- Mixed results across 20 studies — no consistent benefit from supplementation
- Some studies find lower B12 levels in hair loss patients, others do not
- No large-scale RCTs testing B12 supplementation specifically for hair regrowth
- Supplementation may only help if a genuine B12 deficiency is present
Key Study Findings
retrospective observational
n=113
Telogen Effluvium Following Coronavirus Disease-2019 Infection: A Retrospective Study of 113 Cases.
Dose: None
vs: Placebo
効果: None
None
Retrospective cohort
n=2851
Retrospective Review of 2851 Female Patients With Telogen Effluvium: A Single-Center Experience.
Dose: None
vs: Placebo
効果: Ferritin low in 46.5% of patients; iron deficiency in 29.5%
p<0.05
Review
Medical Marijuana and Treatment Personalization: The Role of Genetics and Epigenetics in Response to THC …
Dose: None
vs: None
Outcome: None
効果: None
None
対象集団: Review of pharmacogenomics of THC and CBD
case-control study
n=180
A comprehensive investigation of biochemical status in patients with telogen effluvium: Analysis of Hb, ferritin, …
Dose: not applicable
vs: Placebo
効果: None
None
Cross-Sectional Study
n=108
Evaluation of the relationship of digital phototrichogram findings of patients with diffuse hair loss with …
Dose: None
vs: Placebo
効果: None
0.05
Case-control
n=973
Micronutrient Deficiencies and Digital Computerized Phototrichogram Analysis in Telogen Effluvium: a Retrospective Correlation Study in …
Dose: None
vs: Placebo
効果: r=0.417 (HGB and AHR in females)
p=0.008
Key Statistics
19
研究数
8130
参加者数
↔
Mixed
F
グレード
Referenced Papers
Retrospective Review of 2851 Female Patients With Telogen Effluvium: A Single-Center Experience.
Other
Journal of cosmetic …
2025
4 件の引用
Genes
2025
1 件の引用
Telogen Effluvium Following Coronavirus Disease-2019 Infection: A Retrospective Study of 113 Cases.
Other
International journal of …
2025
Journal of cosmetic …
2024
7 件の引用
Northern clinics of …
2024
1 件の引用
JAMA
2023
49 件の引用
Dermatology practical & …
2023
4 件の引用
Sports medicine - …
2022
34 件の引用
Frontiers in pharmacology
2022
31 件の引用
Journal of cosmetic …
2022
22 件の引用
Turkish journal of …
2022
8 件の引用
Journal of pain …
2020
56 件の引用
NonScarring Diffuse Hair Loss in Women: a Clinico-Etiological Study from tertiary care center in North-West India.
Observational
Journal of cosmetic …
2019
25 件の引用
American journal of …
2017
104 件の引用
Journal of drugs …
2016
56 件の引用
Dermatology research and …
2016
26 件の引用
Acta dermatovenerologica Croatica …
2016
6 件の引用
Prostaglandins, leukotrienes, and …
2015
40 件の引用
Clinical and experimental …
2009
34 件の引用
Dermatologic clinics
1993
38 件の引用
Dosage & Usage
mg = milligrams · mcg = micrograms (1,000× smaller) · IU = International Units
一般的な使用量
- general:
- 2.4 mcg/day
- deficiency:
- 1,000-2,000 mcg/day
上限量： No established UL
研究で検討された用量
| 用量 | 期間 | 効果 | N |
|---|---|---|---|
| None | -- | Neutral | 113 |
| None | -- | Neutral | 2851 |
| None | -- | Mixed | -- |
| not applicable | -- | Mixed | 180 |
| None | -- | Mixed | 108 |
| None | -- | Positive | 973 |
| None | -- | Neutral | -- |
| 300 mg single dose | -- | Mixed | 9 |
推奨摂取タイミング： With meals; sublingual form can be taken any time
Safety & Side Effects
報告されている副作用
- ⚠ Generally well tolerated even at high doses
- ⚠ Rare allergic reactions (itching, swelling)
- ⚠ Mild diarrhea or nausea at very high doses
既知の相互作用
- ● Metformin (reduces B12 absorption by 10-30%)
- ● Proton pump inhibitors and H2 blockers (reduce B12 absorption)
- ● Colchicine (may reduce B12 absorption)
耐容上限摂取量： No established UL
サプリメントの摂取を開始する前に、必ず医療専門家にご相談ください。
Frequently Asked Questions
Does ビタミンB12 help with 栄養不足による脱毛症?
Based on 19 studies with 8,130 participants, there is insufficient evidence at this time that ビタミンB12 may support 栄養不足による脱毛症 management. Our evidence grade is F (Evidence Against).
How much ビタミンB12 should I take for 栄養不足による脱毛症?
Studies have used various dosages. A commonly studied range is 2.4 mcg/day. Always consult your healthcare provider before starting any supplement regimen.
Are there side effects of ビタミンB12?
Reported side effects may include Generally well tolerated even at high doses, Rare allergic reactions (itching, swelling), Mild diarrhea or nausea at very high doses. Most side effects are mild and dose-dependent. Consult your doctor if you experience any adverse reactions.
How strong is the evidence for ビタミンB12 and 栄養不足による脱毛症?
We rate the evidence as Grade F (Evidence Against). This rating is based on 19 peer-reviewed studies with 8,130 total participants. The overall direction of effect is mixed.
Related Evidence
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