The Four Layers of Skin Nutrition: Structure, Lipids, Antioxidants, Cofactors

Most supplement conversations still revolve around single ingredients — “Should I take collagen?” or “Is vitamin C enough?” From a skin-biology perspective, that’s too narrow. Aging reflects gradual changes across several interconnected systems, not just one missing component.

A practical way to understand internal skin nutrition is to think in terms of four layers:

• Structure — collagen, elastin, and the dermal matrix
• Lipids — ceramides, fatty acids, and barrier architecture
• Antioxidants — carotenoids, polyphenols, and endogenous defenses
• Cofactors — vitamins and minerals required for synthesis and repair

These four layers form the biological basis of skin longevity. They are constantly interacting. Supporting one without the others is possible, but less efficient than addressing the system as a whole. 

Layer 1: Structure — Collagen, Elastin, and the Dermal Matrix

The dermal matrix provides firmness, elasticity, and support for the visible surface. With age and UV exposure, collagen production slows while collagen breakdown increases, driven in part by oxidative stress and matrix-degrading enzymes.^8–10

Oral collagen peptides have been studied in multiple randomized trials and meta-analyses. These studies report that specific peptide profiles can:

• improve skin elasticity and hydration over 4–12 weeks^1–4
• reduce wrinkle depth and roughness relative to placebo^2–4
• increase dermal density or matrix-related markers in some protocols^2–4

Silicon, often provided as orthosilicic acid in trials, appears to support collagen organization and mechanical properties, although the evidence base is smaller than for collagen peptides.⁵

Layer 2: Lipids — Barrier Architecture and Hydration

The outer stratum corneum depends on a carefully organized mixture of ceramides, cholesterol, and fatty acids. This lipid “mortar” holds corneocytes together and controls water loss. With age, barrier quality can decline, increasing transepidermal water loss (TEWL) and sensitivity, and making fine lines more apparent.^8–10

Oral ceramide and glucosylceramide complexes have been investigated for their ability to influence hydration from within. Human data suggest that wheat-derived ceramide complexes can:

• increase skin hydration over several weeks
• reduce TEWL compared with placebo
• improve subjective comfort in dry or mature skin⁶

These internal lipid supports are not a substitute for topical barrier repair, but they appear to complement topical ceramides by feeding lipid balance from both sides.

Layer 3: Antioxidants — Managing Oxidative Stress

Oxidative stress arises when reactive oxygen species (ROS) outpace the skin’s defenses. UV radiation, visible light exposure, pollution, and normal metabolism all contribute.^8–10 ROS can damage collagen, elastin, lipids, and DNA, and can influence pigmentation and texture.

Internal antioxidant systems include both endogenous enzymes and diet-derived compounds. Among the latter, three groups are particularly relevant in human skin research:

Carotenoids

Carotenoids (such as beta-carotene, lutein, and zeaxanthin) accumulate in the skin and can modestly increase resistance to UV-induced erythema when taken consistently over weeks.^7,11,12 Trials have shown:

• reduced erythema and increased MED after carotenoid supplementation¹¹
• improvements in tone metrics and overall appearance with lutein/zeaxanthin combinations⁷

Astaxanthin

Astaxanthin is a xanthophyll carotenoid with membrane-spanning properties. Reviews and clinical work suggest it may support:

• improvements in elasticity and fine lines in some RCTs²
• protection against UV-induced changes when combined with other actives²

Polyphenols and Mixed Antioxidant Blends

Polyphenol-rich complexes, such as standardized red orange extracts, have been studied for photoprotection and tone support. Human data report:

• reduced markers of oxidative stress after UV exposure
• improvements in tone and radiance metrics over 8–12 weeks^3,13,14

These effects are modest compared with sunscreen, but they contribute to a broader antioxidant environment that influences how skin handles cumulative exposure.

The antioxidant layer is where carotenoids, polyphenols, and internal antioxidants buffer oxidative stress from UV, pollution, and metabolism. For deeper dives into each of these systems, see Oxidative Stress, Skin, and Internal Antioxidant Support, Polyphenols for Skin: Human Data on Tone, Redness & Photobiology, and Carotenoid Supplements for Skin: What Human Studies Actually Show.

Layer 4: Cofactors — Vitamins and Minerals for Synthesis and Repair

Structural and antioxidant pathways depend on cofactors — vitamins and minerals required by enzymes that build collagen, regulate lipids, and neutralize ROS.

Vitamin C

Vitamin C is essential for collagen synthesis, functioning as a cofactor for prolyl and lysyl hydroxylases involved in collagen stabilization. It is also a water-soluble antioxidant and participates in regeneration of oxidized vitamin E.^15,16

Other Micronutrients

Other micronutrients contribute indirectly:

• Niacinamide supports energy metabolism and, topically, barrier and tone pathways.
• Zinc and selenium are required for endogenous antioxidant enzymes that manage superoxide and peroxides.^8–10,15

These cofactors do not “target wrinkles” in isolation, but they are required background conditions for collagen formation, barrier maintenance, and antioxidant function to proceed normally.

How the Four Layers Interact

These four layers do not operate in isolation:

• Oxidative stress accelerates collagen breakdown and damages barrier lipids.^8–10
• Barrier disruption increases susceptibility to environmental insults, amplifying oxidative load.
• Antioxidant insufficiency allows ROS to accumulate, placing more pressure on repair pathways.^8–10,13,14
• Cofactor deficiencies impede both synthesis and repair, narrowing the margin for recovery.^15,16

A coherent internal skin-nutrition strategy therefore tries to cover all four layers at once, not in a piecemeal fashion.

Where Advanced Skin Nutrition Fits In

Advanced Skin Nutrition was designed with these four layers in mind:

• Structure: defined collagen peptides and silica to support dermal matrix properties.^1–5
• Lipids: Ceramosides™ phytoceramides and lipid support to help reinforce barrier hydration.⁶
• Antioxidants: carotenoids (including lutein, zeaxanthin, beta-carotene), astaxanthin, and polyphenols from standardized extracts to support oxidative balance and tone.^2,7,11–14
• Cofactors: vitamin C, niacinamide, zinc, and selenium to support collagen pathways and endogenous antioxidant systems.^8–10,15,16

The goal is not to duplicate topical products, but to provide an internal foundation that supports what skincare, sunscreen, and professional treatments are already trying to achieve on the surface.

Frequently Asked Questions

Isn’t collagen enough if I already take a good powder?

Collagen can support structural aspects of skin, but it does not directly address barrier lipids, antioxidant capacity, or micronutrient cofactors. Structural support is one piece of the system; oxidative stress and lipid balance still influence how that structure holds up over time.^1–4,8–10

Do I need separate products for each layer?

Not necessarily. The key is that all four layers are represented in your overall pattern — through diet, lifestyle, and any formulations you choose. Some people prefer multiple targeted products; others prefer a single formulation that covers multiple pathways alongside a nutrient-dense diet.

How long does it take to see changes if I support all four layers?

Most human trials of collagen peptides, carotenoids, ceramides, and antioxidant complexes evaluate outcomes over 4–12 weeks. Early changes often involve hydration and comfort; structural and tone-related endpoints tend to follow over longer timeframes.^{1–4,6–7,11–14}

Do internal approaches replace topical care?

No. Internal and topical strategies work in different compartments. Internal approaches support structure, lipids, and antioxidant networks from within, while topical products and sunscreen are still crucial for surface-level protection and targeted concerns.^{1–4,8–10,15,16}