Vitamin A in acne vulgaris
Thirty-five patients with acne vulgaris were studied regarding vitamin A and E status, and the safety and efficacy of vitamin A supplementation over a 6-week period. The patients studied had significantly lower plasma vitamin A levels than normal controls and a lower frequency of consumption of foods rich in vitamin A. Vitamin E status in the patients was similar to that of normal controls. Vitamin A supplementation had no significant effect on plasma vitamin A levels during the study, but the patients had significant (P < 0.005) higher levels at 6 weeks post-supplementation when compared with pre-supplementation values. Furthermore, vitamin A supplementation was associated with a significant and progressive increase in plasma retinol ester concentration. Vitamin A at the dose administered was ineffective in the treatment of acne and was associated with symptoms compatible with hypervitaminosis A only in a small percentage of patients. Since its recognition in 1909 and 1913 and isolation in 1937, vitamin A received wide attention for its nutritional consequences of deficiency and, more recently, for its pharmacotherapeutic role in oncology and dermatology. In the latter field vitamin A was first used in the treatment of acne vulgaris, in view of the resemblance of the acne lesions, and other dermatological conditions such as pityriasis rubra pilaris, ichthyotic states, Darier's disease, to those seen in hypovitaminosis A. Since then a number of studies have shown that vitamin A in ineffective in the treatment of acne, whereas other investigators claim efficacy with daily doses in excess of 200,000 IU. It is generally accepted that the administration of such high doses, particularly over prolonged periods, may be associated with symptoms and signs of hypervitaminosis A, although one should hasten to add that there appears to exist considerable individual susceptibility.