Vitamin C (Ascorbate) vs Vitamin D3 (+ K2)
Both are used for skin & hair. Here's how they compare on human evidence, mechanism, safety and availability — in plain English.
| Vitamin C (Ascorbate) | Vitamin D3 (+ K2) | |
|---|---|---|
| Human evidence | ★★★★☆ | ★★★★★ |
| Legal status | OTC Supplement | OTC Supplement, Prescription |
| How it works | Cofactor for prolyl/lysyl hydroxylases (P4HA1) in collagen synthesis, for dopamine-β-hydroxylase (noradrenaline), and a water-phase antioxidant regenerating vitamin E. | Cholecalciferol → 25(OH)D (liver) → 1,25(OH)₂D (kidney), which binds the VDR (vitamin D receptor), a nuclear transcription factor regulating 200+ genes including those for calcium transport, immune peptides, and testosterone synthesis. K2… |
| In plain English | Your body literally can't build collagen without it, and it mops up free radicals. Take it with collagen for tendons. | A hormone your skin makes from sunlight that switches on hundreds of genes. Indoor life (very common in Singapore) leaves most people deficient, which quietly lowers testosterone, immunity, and mood. |
| Bottom line | — | Highest-value fix if you work indoors. Almost everyone benefits. |
| Availability | Available over the counter | Prescription only |
Which is better for skin & hair?
Vitamin D3 (+ K2) has the stronger human-evidence rating (★★★★★ vs ★★★★☆), but the right choice still depends on your goal, tolerance and budget.
Full breakdowns: Vitamin C (Ascorbate) · Vitamin D3 (+ K2).
Common questions
Is Vitamin C (Ascorbate) or Vitamin D3 (+ K2) better for skin & hair?
Vitamin D3 (+ K2) has the stronger human-evidence rating (★★★★★ vs ★★★★☆), but the right choice still depends on your goal, tolerance and budget.
What's the difference between Vitamin C (Ascorbate) and Vitamin D3 (+ K2)?
Vitamin C (Ascorbate): Your body literally can't build collagen without it, and it mops up free radicals. Take it with collagen for tendons. — Vitamin D3 (+ K2): Highest-value fix if you work indoors. Almost everyone benefits.