Background  Vitamin C has been used for the treatment of hyperpigmented diseases. However, there is no study available on hypopigmenting effect of multivitamin.

Objectives  To investigate the inhibitory effects of multivitamin and vitamin C on melanogenesis.

Methods  We assessed the effect of multivitamin and vitamin C on cell viability, melanogenesis, and mushroom tyrosinase. The antioxidant activity of multivitamin and vitamin C was measured. We performed the Western blot analysis to study the effect of multivitamin and vitamin C on the expression of tyrosinase, microphthalmia-associated transcription factor (MITF), extracellular signal-regulated kinase (ERK), and Akt/protein kinase B. In a clinical trial, 20 melasma patients were treated with split face iontophoresis using either multivitamin or vitamin C. We evaluated the hypopigmenting effects of multivitamin and vitamin C through colorimetric measurement.

Results  Both vitamin C and multivitamin inhibited melanogenesis with low cytotoxicity. Multivitamin reduced melanin contents greater than vitamin C. However, the effects of vitamin C are greater than those of multivitamin on mushroom tyrosinase inhibition and antioxidation. In the Western blot, the reduced tyrosinase expression and MITF level were observed only in multivitamin-treated group, and not in vitamin C-treated group. No changes of ERK and Akt activation were observed in both multivitamin and vitamin C-treated groups. After 12 weeks of treatment with iontophoresis, both multivitamin and vitamin C were effective for melasma.

Conclusions  Multivitamin has shown more anti-melanogenic effect than vitamin C via the downregulation of MITF.