Objective To investigate vitamin D ( VD) level and its influencing factors in 4-15-year-old children in southwest of Zhejiang province, so as to guide intervention strategy for improving VD level. Methods A total of 2 620 4 -15-year-old healthy children who visited Lishui People's Hospital for regular physical check-up between January and December 2014 were divided into 4 age groups, namely 4 -6 years (kindergarten), 7 -9 years (lower grades in primary school), 10 -12 years (higher grades in primary school), and 13-15 years (junior middle school).We randomly selected 200 children from each age group using a random number table.A survey using self-developed questionnaire was conducted to obtain information regarding diet, exposure to sunlight, and VD supplement.Serum 25-( OH) D level was measured with electro-chemiluminescence.VD nutritional status and composition, diet, sunlight exposure, VD supplement were com-pared among the groups.Results In southwest Zhejiang, the mean VD level in primary and middle school students was ( 24.76 ±8.39 ) μg/L, clinical deficiency rate was 31.5%, subclinical deficiency rate was 45.0%, and only 23.5% reached the appropriate level, which was even lower ( 14.5%) in junior middle school students.The VD deficiency rate elevated significantly along with the growth of age (P=0.036).The level of VD was positively correlated with sunlight exposure and VD supplementation, and showed significant in-ter-group differences ( all P<0.05 ) .Conclusions The nutritional status of VD is unfavorable and sunlight exposure insufficient in primary and middle school students in southwest Zhejiang province.We should encour-age students to take more outdoor activities and increase sunlight exposure to improve their VD nutritional sta-tus.Children >7 years should be given more attention to in the intervention of increasing sunlight exposure. Students with difficulties in getting adequate sunlight exposure need VD supplements.

【Objective】 To understand the situation of free blood use of blood donors in Changsha to explore the correlation between free blood use of donors and repeated blood donation behaviors, so as to provide a theoretical basis for the recruitment of voluntary blood donations. 【Methods】 A total of 260 voluntary blood donors were selected by random sampling and divided into reimbursed group(n=97) and unreimbursed group(n=163), based on the results of a questionnaire, inquiring their using of free blood. 【Results】 The reimbursed group differed from the unreimbursed group in all dimensions, including behavioral attitude dimension(Z=3.250, P<0.05), subjective behavioral norm dimension(Z=4.576, P<0.05), and perceptual behavioral control dimension(Z=7.255, P<0.05) and the total score of the scale(Z=8.625, P<0.05), and the differences were statistically significant. 【Conclusion】 The intention to donate again was stronger in donors who experienced free blood use than those didn’t. Such donors are suitable candidates for blood donor recruitment. It is recommended to develop a suitable recruitment strategy for this population and further guarantee the clinical use of blood.

【Objective】 To explore the current status of positive psychological qualities among college students who had participated in voluntary blood donation in Changsha area, so as to demonstrate that scientific blood donation can promote mental health. 【Methods】 From May to June 2022, 1 440 college students in Changsha was selected as the research subjects by stratified random sampling method. They were divided into groups based on their experience of blood donation. A questionnaire survey was conducted using the General Information Questionnaire, the Chinese College Student Positive Psychological Product Quality Scale, and the Repeated Blood Donation Behavior Survey Scale. 【Results】 There were differences in the six dimensions of positive psychological quality among different family and friends in terms of their support for blood donation, blood donation status among different family members, understanding of voluntary blood donation knowledge (P<0.05). There were differences in positive psychological qualities among different levels of blood reimbursement experiences (cognitive dimension, moderation dimension, transcendence dimension), different blood donation times (moderation dimension, interpersonal dimension), different blood donation volumes (moderation dimension, fairness dimension), different comprehensive blood donation experiences (moderation dimension, transcendence dimension, interpersonal dimension, emotional dimension) and reasons for blood donation (cognitive dimension, moderation dimension, interpresonal dimension, emotional dimension, fairness dimension)(P<0.05). The positive psychological quality of college students was positively correlated with their intention to repeat blood donation behavior (P<0.01), and the difference was statistically significant. 【Conclusion】 The positive psychological quality of college students with blood donation experience in Changsha surpassed those without blood donation experience, and their positive psychological quality was positively correlated to their intention to repeated blood donation. Therefore, it is recommended to encourage voluntary blood donation among college students.