Serum vitamin B12 and vitamin D levels among 5-17 years old obese children who admitted to department of pediatrics, Duzce University Medi̇cal School

Obesity is a public health problem which incidence is increasing all over the world nowadays. The onset age of obesity is in ranges 4-11 years, it's important to continue in adulthood and association with diseases such as cardiovascular, hypertension and diabetes mellitus. According to studies conducted in recent years vitamin B12 and vitamin D levels in obese children are lower than normal weight children. In our study 92 obese and 58 non obese patients aged 5-17 years were investigated by 25(OH) vitamin D, vitamin B12 levels, insulin, HbA1c, fasting blood glucose, HOMA-IR, hemoglobin, MCV, MPV, PLT, Ca, P, ALP, PTH, Mg, LDL, HDL, total cholesterol, trigliserid levels. There were no significant differences in the age and sex distrubution between obese and non obese groups. In our study according to USA Endocrine Society vitamin D deficieny classification, in obese group 0-20 ng/ml ratio of the range was significantly higher than the rate those in the non obese group (p<0,001). Also the range 20-30 ng/ml in obese group was significantly lower than those in non obese group. There was no significant difference comparing vitamin B12 levels and deficiency in between obese and non obese groups. In obese group there was a significant negative correlation between vitamin B12 with HOMA-IR and insülin (respectively r1=-0.36, r2=-0.384;p1=0.001, p2=0.000). There was significant negative correlation between vitamin D with HOMA-IR1 and insülin2 (respectively r1=-0.256, r2=-0.258;p1=0.016, p2=0.015). Vitamin B12 levels were compared to all of the cases by age groups; 5-10 years ranged patients have significantly higher vitamin B12 levels than 10-14 years of range (p<0.001) and 14-17 (p=0.002) years range patients. In the study group there was significantly difference in BMI between obese and non obese group. Vitamin B12 deficient group had higher BMI(p=<0.004). In our study there was significantly difference in vitamin B12 and vitamin D levels between insülin resistant patient group with and without (respectively p1=<0.001; p2=<0.001). Finally, according to vitamin B12 levels observed there were no significant difference between both obese and non obese group while obese children had lower vitamin D levels. Vitamin B12 and vitamin D levels showed negative correlation with insülin and HOMA-IR. Vitamin B12 levels were found higher in 5-10 years range obese children. Key words: 25 (OH) vitamin D, child, obesity, vitamin B12, Vitamin D deficiency,