From a review of the literature it appears that local trauma is a factor in the genesis of oral hyperkeratoses.
The major concern of systemic influence has been focused upon vitamin A metabolism. Existing evidence indicates that a vitamin A deficiency can produce oral hyperkeratosis and that therapeutic amounts of vitamin A exert an anti- or dekeratinizing effect on normal or hyperkeratotic oral mucosa.
An attempt was made in this investigation to study, under double-blind conditions (vitamin A versus placebo supplementation), the problem of leukoplakia in terms of its quantitative, qualitative, and histologic attributes.
Within the limits of this experiment, it appears that there is reduction in size, favorable qualitative change in the lesion, and histologic evidence of improvement in a substantial sample of leukoplakic cases subjected to vitamin A supplementation. No such changes were noted in the placebo group.
Within the limitations of this study, there is no clinical and biochemical (serum carotene) correlation.
The clinical and biochemical findings reported here are in accord with the limited studies reported by other investigators.