Purpose: We investigated the relationship of 25-hydroxyvitamin D (25[OH]D) level with obesity and atherosclerosis in Japanese adolescents. Methods: We examined 492 children (247 boys and 245 girls) aged 12–13 years. The serum 25(OH)D level was compared among underweight, healthy weight, and overweight children. Spearman correlation coefficient analysis was performed to examine the relationships between the 25(OH)D level and body mass index (BMI), plasma lipids, and blood pressure and to compare the latter between the normal (≥20 ng/mL) and low (<20 ng/mL) 25(OH)D groups. Further, we performed a multiple regression analysis to assess the effect on the 25(OH)D level. Results: The serum 25(OH)D level was significantly lower in overweight (20.5±2.7 ng/mL) than in healthy-weight boys (22.4±3.3 ng/mL) (P=0.004). Spearman correlation coefficients comparing the relationship of the 25(OH)D level with BMI, high-density lipoprotein cholesterol (HDL-C), and atherogenic index indicated significance in boys (ρ=-0.238 [P<0.0001], ρ=0.197 [P=0.002], and ρ=-0.146 [P=0.022], respectively). In boys, the multiple regression analysis results showed that BMI had negative and HDL-C had positive effects on the 25(OH)D level. The first was higher and the latter was lower in boys with low 25(OH)D level than in those with normal levels, respectively (P<0.05). No significant correlations were detected in girls. Conclusion Low serum 25(OH)D level was associated with obesity and increased atherogenic risk in adolescent boys only. This sex difference was probably mediated by body composition, sun exposure, estrogen, and adiponectin, which are characteristics of puberty.

We investigated the effects on medical education of early exposure of undergraduate students to a summer camp for children with asthma. An objective evaluation by the editorial staff found final improvements in the following areas (in descending order of frequency): learning of basic medical behavior (91% of students); cooperative attitude of medical staff in general treatment with the patient and the patient's family (88%); understanding of childhood growth and development (80%); knowledge of childhood asthma (69%); and mastery of basic techniques for therapy and examination (41%). The differences in the ratio of improvement (%) before and after visiting the camp, were (in descending order of frequency): cooperative attitude of medical care staff in general medical treatment with the patient and the patient's family (47%); understanding of childhood growth and development (45%); knowledge of childhood asthma (38%); learning of basic medical manner (34%); and mastery of basic techniques for therapy and examination (25%). These findings suggest that a summer camp is useful for exposing undergraduate medical students to children with asthma and is effective for helping them understand patients and family-oriented pediatric medicine.