Vitamin AVitamin A
vitamin
Vitamin A
Vitamin A
别名: Retinol, Retinyl palmitate, Beta-carotene (provitamin A)
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About
Vitamin A plays a critical role in cell differentiation and sebum production in hair follicles. Adequate vitamin A supports normal hair cycling, while both deficiency and excess can contribute to hair loss. Retinoids regulate keratinocyte proliferation in the follicular epithelium.
How It Works
Retinoid receptors (RAR/RXR) in dermal papilla cells regulate hair follicle cycling; vitamin A supports sebaceous gland function and epithelial cell differentiation.
Evidence For Conditions
| 健康状况 | 等级 | 研究数量 | 受试者 | |
|---|---|---|---|---|
| 营养缺乏性脱发 | D | 4 | 1 | 查看 → |
| Scalp Inflammation (Folliculitis & Dermatitis) | D | 4 | 1 | 查看 → |
Side Effects
- Hair loss at excessive doses (hypervitaminosis A)
- Dry skin and lips
- Headache and nausea at high doses
- Teratogenicity — contraindicated in pregnancy at high doses
Drug & Supplement Interactions
- Retinoid medications (isotretinoin, tretinoin — additive toxicity risk)
- Tetracycline antibiotics (increased intracranial pressure risk)
- Anticoagulants (high-dose vitamin A may increase bleeding risk)
- Hepatotoxic drugs (additive liver stress at high doses)
请务必告知您的医疗保健提供者您正在服用的所有补充剂。
Related Ingredients
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