Vitamin D levels in children with severe hemophilia A: an underappreciated deficiency.

Osteoporosis in hemophilic patients is a significant problem. The causes of osteoporosis in hemophilic patients are lack of adequate exercise, multiple hemorrhage and inflammation, and low vitamin D levels. The aim of this study was to retrospectively determine the frequency of vitamin D deficiency and insufficiency in children with severe hemophilia A. Forty-seven children with severe hemophilia were included in the study. None of the patients had previously received vitamin D supplementation. No patient had clinical or radiologic findings of rickets or seropositivity of hepatitis C virus or HIV. The mean age of the patients was 11.64 ±â€Š5.70 (range, 2-18) years. The mean vitamin D level was 16.35 ±â€Š7.49 ng/ml (range, 3.25-33.80). Vitamin D levels were below 10 ng/ml (severe vitamin D deficiency) in 9 cases (19%), between 10 and 19.99 ng/ml (vitamin D deficiency) in 23 cases (49%), between 20 and 29.99 ng/ml (vitamin D insufficiency) in 13 cases (28%), and above 30 ng/ml (normal vitamin D level) in 2 cases (4%). The mean serum levels of 25-hydroxy vitamin D in the children with hemophilia during winter and autumn were significantly lower than that during summer (P = 0.0028 and P = 0.0091, respectively). A majority of our hemophilic patients (96%) had low vitamin D levels. The study showed that the risk of vitamin D deficiency is the most highest during winter and autumn. Normal lifelong vitamin D levels are especially important in hemophilia because of the possible synergistic effect of vitamin D levels on periarticular and general osteoporosis, which is intrinsic to hemophilic conditions. We advise routine checking of vitamin D levels twice a year and vitamin D supplementation to maintain its level between 30 and 100 ng/ml.

Hair selenium status in children with leukemia and lymphoma.

Selenium (Se) is a trace element contributing to the structure of antioxidant system that saves cells from reactive oxygen species. Low serum Se levels have been reported in pediatric and adult patients with cancers. On the other hand, hair Se levels, predicting the long-term body Se status, have been reported in only adult patients with cancer. The aim of the study was to investigate the hair Se status in children with newly diagnosed lymphoid malignancies and the relation between malnutrition and Se deficiency. Thirty patients with leukemia (n=17) and lymphoma (n=13), and 25 healthy controls were enrolled to the study. Se was determined with atomic absorption spectrophotometrical method. Hair Se levels of the patients were significantly lower than those of control group [666.96+/-341.46 ng/g vs. 1019.22+/-371.83 ng/g (P<0.001)]. Children with lymphoma had lower Se than the children with acute lymphoblastic leukemia but not statistically significant [547.03+/-283.67 ng/g vs. 758.67+/-361.05 ng/g (P>0.05)]. Malnourished patients (11/30) had lower hair Se levels (483.51+/-235.55 ng/g) than those of the controls (P=0.036), whereas the Se levels of the patients who had no malnutrition (773.17+/-352.92 ng/g) were also lower than those of the controls but not statistically significant (P=0.053). There was no correlation between age, sex, and the hair Se levels. In this study, we found that hair Se levels of the children with leukemia and lymphoma, especially those of malnourished patients, were lower than those of controls. Additional studies are needed to determinate whether low levels of hair Se may play a role in carcinogenesis.

Reduced bone mineral density in childhood chronic idiopathic thrombocytopenic purpura treated with high-dose methylprednisolone.

PURPOSE: To evaluate whether repeated courses of high-dose methylprednisolone (HDMP) affect the lumbar spine bone mineral density (BMD) in children with chronic idiopathic thrombocytopenic purpura (ITP). MATERIALS AND METHODS: This study included 24 patients with chronic ITP and 149 healthy controls. The patients were allocated into three groups according to the number of HDMP courses (30 mg/kg per day as a single dose for 7 days); group 1 (10 patients), group 2 (9 patients), and group 3 (5 patients) had received less than 5, 6-10, and more than 10 courses, respectively. Lumbar spine BMD and body composition were measured using dual energy X-ray absorptiometry of lumbar spine (L2-L4), and volumetric bone mineral density (vBMD) values were calculated and compared with the controls. The z score of the vBMD was also calculated and compared in the patients of each other groups. Serum markers of the bone turnover were measured to exclude other factors that could effect BMD. RESULTS: The vBMD values of the patients, corrected BMDs for age, were significantly lower than the values of controls (P = 0.018). It was significantly lower in group 3 than groups 1 and 2 (P = 0.005 and P = 0.006, respectively), but there was no statistically significant difference between groups 1 and 2 (P = 0.87). The vBMD z scores were significantly lower in group 3 than in groups 1 and 2 (P = 0.003 and P = 0.004, respectively), and also in group 2 than in group 1 (P = 0.034). There were a weak negative correlation between the cumulative dose of HDMP and vBMD (r = -0.39, P = 0.054), and strong negative correlation between the cumulative dose of HDMP and vBMD z score (r = -0.63, P = 0.001). CONCLUSION: Children with chronic ITP are at risk for decreased BMD because of the repeated courses of HDMP; especially more than 2100 mg of cumulative dose. We therefore recommend that BMD should be monitored in patients with chronic ITP who received repeated courses of HDMP.

Does vitamin A prevent high-dose-methotrexate-induced D-xylose malabsorption in children with cancer?

PURPOSE: Our aim was to explore whether vitamin A has protective effect on high-dose-methotrexate (HDMTX)-induced intestinal D-xylose malabsorption in children with leukemia and lymphoma. PATIENTS AND METHODS: We performed a prospective randomized un-blinded study of vitamin A in 35 children with leukemia and lymphoma who were planned to receive HDMTX 3 g/m(2) and 5 g/m(2), respectively. Twenty-two patients (group 1) received a single dose of 180,000 IU a day before HDMTX was given, and 13 (group 2) received only HDMTX. The vitamin A group received the vitamin only once. Oral D-xylose absorption tests before and 7 days after HDMTX were carried out to evaluate intestinal absorption. Retinol-binding protein (RBP) levels prior to therapy were also measured for vitamin A status. RESULTS: Although we observed no difference of HDMTX-induced toxicity, including hematological, dermatological, systemic, and other toxicities, between groups, the D-xylose absorption test was significantly better in-group 1 ( p=0.030). Absorption was decreased in five of 22 patients (23%) who received vitamin A comparing to eight of 13 (62%) who received only HDMTX ( p=0.033). RBP levels were lower than normal in 13 of 22 patients in-group 1 and nine of 13 in group 2. In patients whose RBP levels were lower than normal, HDMTX-induced toxicity was lower in the group 1 than group 2 but not statistically significant. No sign of vitamin A toxicity was observed throughout the study. CONCLUSION: The administration of vitamin A before HDMTX may protect against drug-induced D-xylose malabsorption in children with cancer. Further studies are apparently needed to clarify the full benefits of vitamin A in preventing HDMTX-induced mucosal damage.