Dermatologic Disease Associations With Cobalamin Deficiency
Vitiligo can be a manifestation of cobalamin deficiency, but the two are not associated in a majority of cases of either disease. This makes it difficult to determine when cobalamin deficiency should be investigated in patients presenting with vitiligo. Karadag et al. compared various serum markers of cobalamin deficiency, including cobalamin, folic acid, homocysteine, and holotranscobalamin in a group of 69 patients with vitiligo and 52 individuals in the control group. They found that the vitiligo group had higher homocysteine and hemoglobin levels and lower levels of vitamin B12 and holotranscobalamin, which is considered the earliest marker of deficiency. Their group suggested the association may be due to a common genetic background among patients with cobalamin deficiency, hyperhomocysteinemia, and vitiligo. Two previous studies had investigated the association of elevated homocysteine levels and vitiligo, with conflicting results. Shaker and El-Tahlawi showed that homocysteine levels were significantly higher in 26 patients with vitiligo than in healthy controls, while Balci et al. found no significant difference in the levels of homocysteine between 48 patients with vitiligo and the control group. Similarly, cobalamin as a therapy for vitiligo has yielded contradictory results in the literature. In a study of 15 patients with vitiligo, eight of the patients experienced repigmentation with prolonged oral folic acid and ascorbic acid and parenteral vitamin B12 supplementation. However, another study of 27 patients compared ultraviolet (UV)-B therapy alone and UVB therapy with vitamin B12 and folic acid, and found no significant difference in the repigmentation rates between the two groups. While there may be a relationship between cobalamin deficiency and vitiligo, further research is needed to elucidate the nature of the association and the clinical application.
Recurrent aphthous stomatitis can be a chronic and debilitating disease refractory to many therapies. Atrophic glossitis is a well-known manifestation of cobalamin deficiency, but aphthous stomatitis also appears to be related to cobalamin deficiency. Patients with recurrent minor aphthous stomatitis were found to have reduced dietary intake of cobalamin and folate by energy-adjusted nutrient density when compared with age- and gender-matched subjects. No difference was noted when examining vitamin E, vitamin B6, niacin, thiamin, vitamin C, or vitamin A. In a randomized, double-blind, placebo-controlled trial, a 1,000 mcg dose of sublingual vitamin B12 was an effective therapy for the treatment of recurrent aphthous stomatitis regardless of the patients' serum vitamin B12 level.
Acne Treated With Isotretinoin
Karadag et al. studied 68 patients with acne vulgaris and found that isotretinoin therapy reduced their vitamin B12, folic acid, and holotranscobalamin levels while elevating their homocysteine. It was suggested that this cobalamin deficiency may account for the neuropsychiatric side effects of isotretinoin treatment.
Cobalamin has been used as treatment for many dermatological diseases, even when no clinical or subclinical deficiency exists. Topical cobalamin has shown promise as a safe treatment for atopic dermatitis. A randomized, controlled study involving 49 patients with atopic dermatitis tested 0.07 % cyanocobalamin cream for 8 weeks on one side of the body and vehicle on the other side. The cyanocobalamin cream was well tolerated and seemed to work well from the perspective of both the patient and the investigators. The modified Six Area Six Sign Atopic Dermatitis score was used; this measures dryness/desquamation, itching, erosion, lichenification, erythema, and infiltration. In this study, the score dropped to a significantly greater extent on the treated side than on the placebo side (55.34 for the vitamin B12 cream vs. 28.87 for the placebo). In vitro, vitamin B12 was able to suppress the cytokine production of T lymphocytes, which may initiate the inflammatory events of atopic dermatitis. This may explain why the vitamin B12 cream was a successful treatment. Another study showed that a preparation of a liposomal hydrogel of adenosylcobalamin (a vitamin B12 derivative) had enhanced skin permeability and was more of benefit than cobalamin itself in the treatment of atopic dermatitis in mice. These results provide hope that cobalamin may provide another therapeutic option in the treatment of atopic dermatitis in the future.
Am J Clin Dermatol. 2015;16(1):27-33. © 2015 Adis Springer International Publishing AG