The clinical and biochemical presentation of vitamin D deficiency and insufficiency in children and adolescents.

AIM: To evaluate the clinical and biochemical findings of the children and adolescents with vitamin D deficiency and insufficiency in order to determine the clinical and biochemical presentation differences between age groups. METHODS: This retrospective study included a review of medical reports of 543 patients (aged between 1-17 years) who were referred to our hospital between October 2011 and May 2012 with symptoms related to vitamin D deficiency or insufficiency. The patients were divided into four groups by age: 1-3 years (Group 1), 4-6 years (Group 2), 7-11 years (Group 3) and 12-17 years (Group 4). Patients diagnosed with vitamin D deficiency or insufficiency were evaluated as to their clinical and biochemical findings. RESULTS: Gender distribution were not statistically different between the four groups. The mean ages of Groups 1-4 were 1.9±0.7, 5.1±0.9, 8.9±1.3, 13.1±1.1, respectively. Major complaints on admission were muscle weakness (91%), low weight gain (failure to thrive) (89%), head deformity (frontal bossing) (35.6%), bone deformity (enlargement of wrist and ankles) (29.7%) for Group 1. Muscle weakness (76%) and low weight gain (failure to thrive) (68%) for Group 2. Leg and chest pain were the major symptoms in Group 3 (57% and 28%, respectively) and in Group 4 (26% and 55%, respectively) as well as high rates of obesity (31% and 63%). The biochemical findings of vitamin D deficiency mostly appeared in the first group who developed vitamin D deficiency due to the lack of vitamin D supplementation. However, in older children, the majority of the patients had low 25 hydroxyvitamin D (25 OHD) values without evidence of biochemical findings of osteomalacia. CONCLUSION: Depending on the degree of deficiency and insufficiency, and the age of the patients, the clinical and biochemical findings varied widely. Children under the age of 3 who either never received vitamin D supplementation or who had been receiving supplementation that was stopped too early were at a greater risk for developing clinically and biochemically proved vitamin D deficiency. In older children, low vitamin D levels mostly resulted in subtle complaints without abnormal biochemical findings.

Effect of vitamin C on oxidative liver injury due to isoniazid in rats.

BACKGROUND: The aim of the present study was to investigate the effect of different doses of vitamin C on oxidative liver injury due to isoniazid (INH) in rats. METHODS: Rats were divided into four subgroups, each containing 10 rats. Group 1 was the control group; group 2, INH 50 mg/kg per day; group 3, INH 50 mg/kg per day + low-dose vitamin C (100 mg/kg per day); group 4, INH 50 mg/kg per day + high-dose vitamin C (1000 mg/kg per day). INH and vitamin C were administered into their stomachs through an oral tube. After 21 days, measurements were made in both serum and homogenized liver tissues. The levels of glutathione (GSH), superoxide dismutase (SOD) and other biochemical variables were measured. Malondialdehyde (MDA), glutathione peroxidase (GSH-px) and vitamin C were measured using commercial kits. RESULTS: Aspartate amino transferase and alanine aminotransferase in group 2 were higher than those in groups 1, 3 and 4 (P < 0.008 for both). Serum and tissue levels of MDA in group 2 were higher than that in groups 1 and 3 (P < 0.008 for both). There was no difference in the SOD levels between the four groups (P= 0.095). Erythrocyte and tissue GSH in group 2 were higher than that in groups 1 and 3 (P < 0.008 for both). Interestingly, erythrocyte and tissue GSH in group 4 were lower than those in group 1 (P < 0.008 for both). Erythrocyte level of GSH-px in group 2 was higher than that in groups 1 and 3 (P < 0.008 for both). CONCLUSIONS: INH-induced liver injury is associated with oxidative stress, and co-administration of low-dose vitamin C may reduce this damage effectively in a rat model. The antioxidant effect of high-dose vitamin C does not seem more potent compared to the low dose.