Vitamins and Medications for Dry Skin (Xerosis)

Understanding Dry Skin

Vitamins That Help Dry Skin

1. Vitamin A (Retinoids)

• Vitamin A and its derivatives (retinoids) regulate keratinocyte differentiation and turnover
• Deficiency causes dry, rough skin and decreased keratin synthesis
• Topical retinol/tretinoin can improve skin texture, reduce scaliness, and support the skin barrier
• Note: excess Vitamin A (hypervitaminosis A) paradoxically causes dry, pruritic skin - so supplementation should be moderate

2. Vitamin D

• Produced in the skin itself via UVB radiation acting on 7-dehydrocholesterol (a cholesterol biosynthesis intermediate)
• Plays a role in epidermal barrier homeostasis and keratinocyte function
• Deficiency is associated with impaired skin barrier function; supplementation can be helpful especially in people with limited sun exposure
• (Fitzpatrick's Dermatology, Lipid Composition of the Stratum Corneum)

3. Vitamin E (Tocopherol)

• A fat-soluble antioxidant found naturally in skin lipids
• Helps protect cell membranes from oxidative damage
• Used in topical formulations as a skin-conditioning agent
• Supports the lipid barrier of the stratum corneum

4. Vitamin C (Ascorbic Acid)

• Essential for collagen synthesis and skin structural integrity
• Deficiency results in impaired wound healing and fragile skin
• Topical Vitamin C serums can support skin hydration and barrier function

5. Vitamin B3 (Niacinamide)

• Increases ceramide and free fatty acid production in the skin
• Reduces TEWL and improves skin barrier function
• Effective topically for dry, sensitive skin

6. Essential Fatty Acids (EFAs - Omega-3 and Omega-6)

• Cannot be synthesized by the body - must come from diet
• Essential Fatty Acid Deficiency (EFAD) leads to rough, scaly, erythematous skin with severe permeability barrier defects (Fitzpatrick's Dermatology)
• Sources: fish oil, flaxseed, evening primrose oil
• Dietary supplementation with omega-3s (EPA/DHA) may reduce skin dryness and inflammation

Topical Medications and Agents

First-Line: Emollients and Moisturizers

• Petrolatum intercalates into the stratum corneum and upregulates skin barrier gene expression - Fitzpatrick's Dermatology, p. 406
• Ceramide-containing creams help replace the natural ceramides that are reduced in dry/atopic skin
• Urea-containing moisturizers (5-10%): one study found urea-containing moisturizers provide better clinical results than standard emollients - Fitzpatrick's Dermatology
• Ointments > Creams > Lotions in terms of lipid content and efficacy; lotions are not ideal for severe xerosis
• Apply within minutes of bathing ("soak and smear" technique) to lock in hydration - Dermatology 5e, p. 265

Alpha-Hydroxy Acids (AHAs) / Beta-Hydroxy Acids (BHAs)

• Lactic acid, glycolic acid (AHAs): reduce scaling and corneocyte adhesion; can cause stinging on inflamed skin
• Salicylic acid (BHA): keratolytic; useful in thickened, scaly dry skin

Urea (Prescription Concentrations)

• 20-40% urea: powerful keratolytic for very thick, scaly skin (e.g., ichthyosis, palmoplantar keratoderma)
• Lower concentrations (5-10%) act mainly as humectants

Topical Corticosteroids

• Used when dry skin is accompanied by inflammation (eczema, atopic dermatitis)
• Applied before moisturizers (not after)
• Example: low-potency hydrocortisone 1% for mild inflammatory dry skin

Topical Calcineurin Inhibitors

• Tacrolimus (Protopic), Pimecrolimus (Elidel)
• Non-steroidal anti-inflammatory for eczema/atopic dermatitis-related dry skin
• Useful for sensitive areas (face, skin folds) where steroids carry risk

Systemic / Prescription Medications

Practical Tips

• Bathe in warm (not hot) water for 5-10 minutes, then apply moisturizer immediately
• Use fragrance-free, dye-free products to avoid sensitization
• Choose ointments in winter; lighter creams in summer
• Avoid harsh soaps - use syndet bars (synthetic detergent cleansers) with neutral-to-low pH
• Adults need approximately 250-500g of moisturizer per week for adequate xerosis control - Dermatology 5e