Short answer: Vitamin C fuels the collagen production your skin relies on for firmness and radiance — the formula's first and most prominently stated mechanism.
Why collagen support is listed as the formula's first supporting role
Collagen support appears first among the six supporting roles the formula is built around — a genuinely central mechanism worth understanding first.
Why this specific mechanism is backed by cited, checkable research
Vitamin C's role in skin health is documented in Nutrients (Pullar et al., 2017) — a specific, named journal citation worth reading directly if you want the underlying research.
💡 Worth knowing: support radiant, firmer-looking skin is listed directly among the formula's stated features, tied specifically to this mechanism.