Background and aim VD, affecting many tissues and organs of the body. It exerts many of its effects through contact with VD receptor (VDR) It Is Important especially in immune system.ht

ITP: Purpura. Diminished platelates, treatment by Ivig, Anti D or prednison. Recurrence is common, especially in first weeks of disease. The goal of this study was evaluation Of VD deficiency in ITP patients and influence of its treatment on prognosis.

Materials and methods This was a prospective cross-sectional, study, done 2008–2011 in general ward in Ali-Asghar hospital Tehran Iran.

Serum VD level was measured in ITP patients who admitted in hospital. Levels less than 30 ng/ml were treated by vitamin D, regarding age andwt and platelate level. IVIG was prescribed 1–2gm/kg.

Results There were 50 patients in this study. Mean age was 41/38 (SD = 49.16) months. 46% female and 54% male. Mean vitamin level was 23.99 ± 17.01. Severe deficiency was considered in 12% of the patient’s. moderate deficiency in 36% mild VD deficiency, in 26%. As a whole 74% of them had vitamin D deficiency.

Mean platelet level before treatment was 12800(SD=7748.60) which reached 171200 (SD=1102660.03) after treatment with IVIG which was significant (P < 0.0001).

Conclusion VD deficiency is very common in ITP. Tretment might diminish recurrence. Furtther research is needed.