Vitamin A and its derivatives (notably retinoids like retinol and tretinoin) are widely used in dermatology for improving the appearance of age spots, also known as solar lentigines or liver spots. The scientific rationale is rooted in Vitamin A's ability to modulate cell differentiation and proliferation in the skin. Topical retinoids accelerate epidermal cell turnover, promoting the shedding of pigmented keratinocytes and the emergence of newer, less pigmented skin. Clinical studies have shown that tretinoin (a prescription-strength retinoid) can lighten age spots and improve photoaged skin over several months of use. A number of randomized, controlled trials have supported these effects, though improvement is typically gradual and may be accompanied by skin irritation or sensitivity.

Over-the-counter retinol is less potent than prescription-strength tretinoin but may offer some benefit for mild pigmentation issues with continued use. Oral vitamin A supplementation is not typically used for this indication due to the risk of toxicity and lack of evidence for efficacy. Most of the support for Vitamin A use in age spots comes from topical application in the form of retinoids, rather than dietary or supplemental Vitamin A.

In summary, the use of topical Vitamin A derivatives for age spots is supported by moderate scientific evidence, primarily for prescription-strength products, with a well-understood mechanism of action and documented clinical benefit in reducing hyperpigmentation and improving skin texture over time.