ABSTRACT
Background: Vitiligo is an acquired depigmenting disorder caused by destruction of melanocytes. The
exact etiopathogenesis of vitiligo is unknown. An association between vitiligo and reduced serum levels of
vitamin B12 and folic acid has been found, which are the important cofactors required in the metabolism of
Homocysteine (Hcy).Consequently, Hcy level increases in the circulation. Hcy may mediate melanocyte
destruction via increased oxidative damage, interleukin 6 production and nuclear factor κB (NFκB)
activation.Objective: To evaluate serum homocysteine level, vitaminB12 and folic acid in patients with vitiligo.
Patients and Methods: A total of 70 vitiligo patients of both sexes and 20 healthy controls were enrolled in this
study. Sera from patients and controls were assayed for total Hcy ,vitamin B12 and folic acid .Results: The
mean serum level of Hcy (15.2± 9.3 umol/L) was significantly higher in patients group than that in controls
(8.4± 3.06μmol/L) (P=0.003). The Hcy level was significantly higher in male patients (19.14±9.3 umol/L)
compared to (9.7±5.08 umol/L) in females. Hyperhomocysteinaemia, was detected in 21(30%)of 70 cases of
vitiligo compared to 2(10%) in control group (p= 0. 0.001). The mean Hcy level was (24± 10.5 umol/L)
significantly higher in active patient group than that in stable group (8.33± 3.4 μmol/L) (P=0.001). Mean value
of serum folic acid (8.87± 2.9ng/ml Vs 9.87± 3.22ng/ml) and vitamin B12 ( 297.28±94.251pg/ml Vs323.8±
84.33pg/ml ) were not significantly decreased in vitiligo group as compared to controls.Serum Hcy associated
positively with VASI score.Conclusion: An increased serum Hcy may be a precipitating factor for vitiligo in the
predisposed individuals. Serum Hcy is related to the gender of patients, activity of disease.
Key words: folic acid, homocysteine (Hcy), melanocytes,oxidative damage (VASI) score Vitamin B12, ,Vitiligo

Introduction
Vitiligo is an acquired, idiopathic, and in the majority of cases, a progressive, unpredictable disorder of the
skin. The family history is positive in approximately 30-40% of cases, and there is no gender or racial bias. The
onset is mostly early in life, and it has an estimated worldwide incidence of 0.5-4% (Tobin, et al., 2000). The
cause of vitiligo is unknown, but might involve genetic factors, autoimmunity, neurologic factors, toxic
metabolites, and lack of melanocyte growth factors (Borderé and Nanny, 2009) .Free radical and immune
mediated damage of melanocytes are the most probable pathological mechanism(Dell' Anna, et al., 2007).
Homocysteine (Hcy) is a sulfur‐containing, highly reactive amino acid that is synthesized during protein
catabolism by the conversion of methionine to cysteine. Hcy is metabolized by:
transsulfuration, depending on vitamin B6, and remethylation, depending on folate and vitamin B12 (Fig.1)
(Fowler,1997). Consequently, a nutritional deficiency in either of these two vitamins will result in an increase in
Hcy in the circulation and results in hyperhomocysteinaemia(Montes, et al.,1992). Methionine is an essential
amino acid obtained from protein in the diet. Some of methionine is turned into Hcy. The body turns much of
this Hcy back into methionine with the help of vitamin B12. If someone is B12-deficient, Hcy levels will
increase because this reaction cannot take place (Loehrer, et al.,1997). In most non-vegetarians with elevated
Hcy, folate is more of a problem than is B12. Since vegetarian diets are typically high in folate, elevated Hcy
levels in vegetarians are normally due to a low B12 intake. Increased levels of plasma Hcy may be caused by
several factors such as enzyme defects, deficient or disturbed distribution and/or increased catabolism of the cofactors.
Mean Hcy levels increase throughout life by 3µmol/L to 5µmol/L and the level is higher in men than in
women (Nygard, 1998; Jacques,2001).
An association between vitiligo and reduced serum levels of vitamin B12 and folic acid has been found
(Montes, et al.,1992; Kim, et al., 1999 El-Batawi, et al., 2001). Improvement of this disease after treatment with
vitamin B12 and folic acid has also been reported (Juhlin and Olsson, 1997). Recently ,it has been found that
serum Hcy is elevated in patients with vitiligo (Shaker and El-Tahlawi, 2008)