Vitamin D deficiency continues to be a worldwide problem, especially in developing countries. The aim of this study was to investigate potential risk factors for vitamin D deficiency. Girls (n = 89) aged 13 to 17 y were enrolled in the study. Study subjects were stratified into 3 groups: Group I included girls living in a suburban area; Group II girls lived in an urban area, and Group III girls lived in an urban area and wore concealing clothes for religious reasons. At the end of winter (in April) serum 25-hydroxyvitamin D [25(OH)D] levels were measured and dietary data were collected using questionnaires. Vitamin D deficiency was defined as a serum 25(OH)D concentration < 25 nmol/L, and insufficiency as a 25(OH)D concentration between 25 and 50 nmol/L. The lumbar and femur neck bone mineral densities (BMD) were measured using dual X-ray absorptiometry (DEXA). Overall, 39 girls (43.8%) had vitamin D insufficiency and 19 (21.3%) had vitamin D deficiency. In group III (wearing covered dress) the serum 25(OH)D concentrations (28.13 +/- 12.53 nmol/L) were significantly lower than in the other 2 groups, and within this group, 50% of girls were vitamin D deficient. The lumbar and femur neck BMD of girls with lower 25(OH)D levels did not differ from those with adequate vitamin D levels. We conclude that vitamin D deficiency is an important problem in Turkish adolescent girls, especially in those who follow a religious dress code; therefore, vitamin D supplementation appears to be necessary for adolescent girls.

We analyzed the characteristics of young infants diagnosed with vitamin D deficiency in early infancy at 2 medical centers in Turkey. In this retrospective, cross-sectional study, the clinical, biochemical, and radiographic findings of infants who were diagnosed with vitamin D deficiency at <3 mo of age between May 2001 and May 2003 were reviewed. A total of 42 infants (27 boys and 15 girls) were diagnosed with vitamin D deficiency in the first 3 mo of life during this 2-y period. The age of infants at diagnosis was 60 +/- 19 d (range 32-112 d). The majority (78.7%) presented with seizures. No skeletal deformities were detected clinically, and radiological findings were subtle. All infants had low serum calcium levels but serum phosphorous levels varied. Eight infants (19.0%) had low, 19 (45.3%) had normal, and 15 (35.7%) had elevated serum phosphorous levels. Serum 25-hydroxyvitamin D levels in those measured (29 infants and 15 mothers) were <37.5 nmol/L. Most infants (83%) were exclusively breast-fed without supplemental vitamin D, and none of the mothers were supplemented with vitamin D during pregnancy. All mothers had limited sunlight exposure and 33 of 42 mothers (78.6%) wore concealing clothing. The majority of young infants diagnosed with vitamin D deficiency present with seizures, have low dietary vitamin D intake, and mothers with poor vitamin D reserves. Evaluation of vitamin D status should be included into the workup of hypocalcemia in early infancy. Prevention of deficiency by supplementing pregnant women and infants who are exclusively breast-fed is essential.

A nationwide 'vitamin D prophylaxis augmentation programme' initiated in 2005 in Turkey reduced the prevalence of rickets from 6% in 1998 to 0.1% in 2008 in children under 3 years of age. The programme included free distribution of vitamin D drops to all newborns and infants (0-12 months) visiting primary health stations throughout the country. Free disposal of vitamin D to infants is an effective strategy for preventing vitamin D-deficient rickets.

Objective:Turner syndrome (TS) is a chromosomal disorder caused by complete or partial X chromosome monosomy that manifests various clinical features depending on the karyotype and on the genetic background of affected girls. This study aimed to systematically investigate the key clinical features of TS in relationship to karyotype in a large pediatric Turkish patient population.Methods:Our retrospective study included 842 karyotype-proven TS patients aged 0-18 years who were evaluated in 35 different centers in Turkey in the years 2013-2014.Results:The most common karyotype was 45,X (50.7%), followed by 45,X/46,XX (10.8%), 46,X,i(Xq) (10.1%) and 45,X/46,X,i(Xq) (9.5%). Mean age at diagnosis was 10.2±4.4 years. The most common presenting complaints were short stature and delayed puberty. Among patients diagnosed before age one year, the ratio of karyotype 45,X was significantly higher than that of other karyotype groups. Cardiac defects (bicuspid aortic valve, coarctation of the aorta and aortic stenosis) were the most common congenital anomalies, occurring in 25% of the TS cases. This was followed by urinary system anomalies (horseshoe kidney, double collector duct system and renal rotation) detected in 16.3%. Hashimoto’s thyroiditis was found in 11.1% of patients, gastrointestinal abnormalities in 8.9%, ear nose and throat problems in 22.6%, dermatologic problems in 21.8% and osteoporosis in 15.3%. Learning difficulties and/or psychosocial problems were encountered in 39.1%. Insulin resistance and impaired fasting glucose were detected in 3.4% and 2.2%, respectively. Dyslipidemia prevalence was 11.4%.Conclusion:This comprehensive study systematically evaluated the largest group of karyotype-proven TS girls to date. The karyotype distribution, congenital anomaly and comorbidity profile closely parallel that from other countries and support the need for close medical surveillance of these complex patients throughout their lifespan.

This is the first study to report the incidence and prevalence of Type 1 diabetes in children in Turkey. The incidence of Type 1 diabetes reflects the geographical location of Turkey, bridging Asia and Europe, with the incidence being higher than in Asia but lower than in Europe.