Vitamin A, particularly in the form of topical retinoids (such as tretinoin, a derivative of vitamin A), is scientifically validated for use in treating age spots (also known as liver spots or solar lentigines). Age spots are hyperpigmented areas that develop due to cumulative sun exposure and aging. Topical retinoids work by accelerating cell turnover and promoting the shedding of pigmented, damaged skin cells while stimulating the growth of new, healthy cells. This process can gradually lighten hyperpigmented spots and improve overall skin texture.

Multiple clinical studies have demonstrated that topical retinoids can reduce hyperpigmentation and improve the appearance of age spots over time. For example, tretinoin has been shown to significantly lighten age spots after consistent application for several months. The mechanism is thought to involve inhibition of melanin production and increased epidermal turnover.

However, the evidence largely pertains to topical vitamin A derivatives, not to oral vitamin A or nonspecific forms of vitamin A. The use of generic "vitamin A" for age spots is supported when it refers specifically to these topical formulations. Over-the-counter retinol products (a less potent form of vitamin A) are also widely used, though with somewhat less robust clinical evidence than prescription-strength retinoids.

In summary, the use of topical vitamin A derivatives for the treatment of age spots is supported by scientific evidence, though results can vary, and professional supervision is recommended due to potential side effects such as irritation.