Vitamin D Status And The Relative Factors Of1to36Month Infants And Toddlers Hospitalized In Lanzhou

Objective To study vitamin D status of infants and toddlers hospitalized in Lanzhou and it’s relative factors in order to offer the trend of vitamin D deficiency and the evidence for supplying vitamin D reasonably.Method The level of serum25-dihydroxyvitamin D was seen as an indicator of the vitamin D status. Serum25-dihydroxyvitamin D levels were measured by liquid chromatography-tandem mass spectrometry (LC-MS-MS). We recruited374inpatient infants and toddlers that aged of1to36month in Lanzhou(36°03N latitude). We participated Vitamin D External Quality Assessment Scheme (DEQAS) to detect the bias of25-dihydroxyvitamin D test in our laboratory. Multiple linear regression analysis and logistic regression was used to analyze potential relative factors of vitamin D deficiency which surveyed by a questionnaire.Result①The levels of serum25-dihydroxyvitamin D of infants and toddlers hospitalized in Lanzhou was (30.40±14.88) ng·ml-1. The prevalence of vitamin D deficiency was based on the proposed definition of<20ng·ml-1. Serum25-dihydroxyvitamin D<20ng·ml-1was shown in19.5%of infants and toddlers. There were still3.4%of infants and toddlers with vitamin D deficiency even though they had taken vitamin D supplements recently.②25-dihydroxyvitamin D levels varied with season(p=0.04).Vitamin D levels was the lowest in spring, with the25-dihydroxyvitamin D concentration<20ng·ml-1in29%of participants. The highest vitamin D level was presented in fall,but there were still13%of participants with25-dihydroxyvitamin D <20ng·ml-1.③Many infants under6months were lack of vitamin D seriously [OR=3.668(95%CI:1.251,10.757)]. Compared with infants<6months who were fed with formula, pure breastfeeding and mixed feeding trend to appear to be vitamin D deficiency [OR=40.941(95%CI:5.074,330.361),12.211(95%CI:1.411,105.651)].④The25-dihydroxyvitamin D concentration was positively correlated with vitamin D supplementation and time spent outside [relation coefficient β’)0.208(95%CI:1.915,5.276),0.159(95%CI:1.474,6.107)respectively]. No taking vitamin D supplementation was significantly associated with an increased risk of deficiency [OR=5.211(95%CI:2.476,10.966)].Conclusion Infants under6months was the high risk group of vitamin D deficiency hospitalized in Lanzhou. Serum25-dihydroxyvitamin D levels was the lowest in spring. Therefore, more vitamin D should be supplied in spring and in winter. So the children should be encouraged to pay more attention to the supplementation of vitamin D and being outside which is positive with serum25-dihydroxyvitamin D levels. The vitamin D nutritional status of infants and toddlers aged of1to36months hospitalized in Lanzhou is in need of improvement.