Skin structure and nutritional physiology
The layers of the skin and how they are fed
Key takeaway for patientsSkin is built from the inside. Circulation and nutrition supply it, which is why changes in the skin can reflect general health.
Skin has three layers. The epidermis is the outer barrier and has no blood vessels of its own. The dermis beneath contains collagen, elastin, blood vessels and nerves. The hypodermis is a layer of fat that insulates and cushions.
The epidermis is fed by diffusion from capillaries in the dermis, so skin depends on circulation and on what the blood carries. Protein, vitamin C, vitamin A, zinc and essential fatty acids are all needed to build and maintain it.
Key steps in supplying the skin
- Dermal blood supply
- Capillary loops bring oxygen and nutrients.
- Diffusion to the epidermis
- Nutrients pass from the dermis to the layer above.
- Synthesis
- Fibroblasts and keratinocytes use amino acids, vitamin C and zinc to make structural proteins.
- Renewal
- Cells of the epidermis are replaced continuously from below.
Factors that impair skin structure
Supply and structure are affected by:
- Nutritional deficiency
- Too little protein, vitamin C, zinc or essential fatty acids.
- Poor circulation
- Smoking and vascular disease.
- Glycation
- Raised blood sugar stiffens collagen.
- UV exposure and aging
- Break down collagen and thin the dermis.
Clinical management and physician guidance
Skin is assessed together with nutrition and general health.
- Skin and nutritional assessment
- Examination, with blood tests for nutrition and metabolic health where indicated.
- Physician-guided care
- Diet, sun protection and the care of any underlying condition, as your physician decides.
- Monitoring and follow-up
- Symptoms and markers are reviewed over time, and the plan is adjusted to them.
Research focus in skin physiology
| Core focus area | Biological target | Clinical relevance |
|---|---|---|
| Dermal matrix | Collagen and elastin | Strength and elasticity |
| Nutrient cofactors | Vitamin C and zinc | Synthesis of collagen |
| Microcirculation | Dermal capillaries | Supply to the epidermis |
| Lipids | Essential fatty acids | Barrier function |
Frequently asked questions
- Does diet affect the skin?
- Yes. The skin is built from nutrients carried in the blood, and deficiency shows in it.
- Why does smoking age the skin?
- It narrows small blood vessels and increases oxidative stress, so less reaches the skin.
- Can a skin change reflect general health?
- It can. Dryness, slow healing or pallor are sometimes signs of a deficiency or a medical condition.
Academic references and literature
- Pullar JM, Carr AC, Vissers MCM (2017). The Roles of Vitamin C in Skin Health. Nutrients, 9(8). PMID 28805671.
- Park K (2015). Role of micronutrients in skin health and function. Biomol Ther (Seoul), 23(3), 207-17. PMID 25995818.
- Boelsma E, Hendriks HF, Roza L (2001). Nutritional skin care: health effects of micronutrients and fatty acids. Am J Clin Nutr, 73(5), 853-64. PMID 11333837.
This guide belongs to the Skin Health program