***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND The cholecalciferol inputs required to achieve or maintain any given serum 25-hydroxycholecalciferol concentration are not known , particularly within ranges comparable to the probable physiologic supply of the vitamin . OBJECTIVES The objectives were to establish the quantitative relation between steady state cholecalciferol input and the result ing serum 25-hydroxycholecalciferol concentration and to estimate the proportion of the daily requirement during winter that is met by cholecalciferol reserves in body tissue stores . DESIGN Cholecalciferol was administered daily in controlled oral doses labeled at 0 , 25 , 125 , and 250 micro g cholecalciferol for approximately 20 wk during the winter to 67 men living in Omaha ( 41.2 degrees N latitude ) . The time course of serum 25-hydroxycholecalciferol concentration was measured at intervals over the course of treatment . RESULTS From a mean baseline value of 70.3 nmol/L , equilibrium concentrations of serum 25-hydroxycholecalciferol changed during the winter months in direct proportion to the dose , with a slope of approximately 0.70 nmol/L for each additional 1 micro g cholecalciferol input . The calculated oral input required to sustain the serum 25-hydroxycholecalciferol concentration present before the study ( ie , in the autumn ) was 12.5 micro g ( 500 IU)/d , whereas the total amount from all sources ( supplement , food , tissue stores ) needed to sustain the starting 25-hydroxycholecalciferol concentration was estimated at approximately 96 micro g ( approximately 3800 IU)/d . By difference , the tissue stores provided approximately 78 - 82 micro g/d . CONCLUSIONS Healthy men seem to use 3000 - 5000 IU cholecalciferol/d , apparently meeting > 80 % of their winter cholecalciferol need with cutaneously synthesized accumulations from solar sources during the preceding summer months . Current recommended vitamin D inputs are inadequate to maintain serum 25-hydroxycholecalciferol concentration in the absence of substantial cutaneous production of vitamin BACKGROUND Obese adolescents are at a greater risk of vitamin D deficiency because vitamin D is thought to be sequestered by excess adipose tissue . Poor vitamin D status has been associated with a higher prevalence of the metabolic syndrome , type 2 diabetes , or both in adults and adolescents . OBJECTIVE The objective was to determine in obese adolescents the efficacy and safety of 4000 IU vitamin D3/d and whether subsequent increased circulating concentrations of 25-hydroxyvitamin D [ 25(OH)D ] are associated with improved markers of insulin sensitivity and resistance and reduced inflammation . DESIGN Obese adolescent patients [ n = 35 ; mean ± SD age : 14.1 ± 2.8 y ; BMI ( in kg/m(2 ) ) : 39.8 ± 6.1 ; 25(OH)D : 19.6 ± 7.1 ng/mL ] were recruited from the University of Missouri Adolescent Diabetes and Obesity Clinic and were r and omly assigned to receive either vitamin D3 ( 4000 IU/d ) or placebo as part of their st and ard care . Anthropometric measurements , inflammatory markers ( IL-6 , TNF-α , C-reactive protein ) , adipokines ( leptin , adiponectin ) , fasting glucose , fasting insulin , and HOMA-IR values were measured at baseline and at 2 follow-up visits ( 3 and 6 mo ) . RESULTS After 6 mo , there were no significant differences in BMI , serum inflammatory markers , or plasma glucose concentrations between groups . Participants supplemented with vitamin D3 had increases in serum 25(OH)D concentrations ( 19.5 compared with 2.8 ng/mL for placebo ; P < 0.001 ) , fasting insulin ( -6.5 compared with + 1.2 μU/mL for placebo ; P = 0.026 ) , HOMA-IR ( -1.363 compared with + 0.27 for placebo ; P = 0.033 ) , and leptin-to-adiponectin ratio ( -1.41 compared with + 0.10 for placebo ; P = 0.045 ) . Inflammatory markers remained unchanged . CONCLUSION The correction of poor vitamin D status through dietary supplementation may be an effective addition to the st and ard treatment of obesity and its associated insulin resistance . This trial was registered at clinical trials.gov as NCT00994396 CONTEXT Hypovitaminosis D appears to be on the rise in young children , with implication s for skeletal and overall health . OBJECTIVE The objective of the study was to compare the safety and efficacy of vitamin D2 daily , vitamin D2 weekly , and vitamin D3 daily , combined with supplemental calcium , in raising serum 25-hydroxyvitamin D [ 25(OH)D ] and lowering PTH concentrations . DESIGN This was a 6-wk r and omized controlled trial . SETTING The study was conducted at an urban pediatric clinic in Boston . SUBJECTS Forty otherwise healthy infants and toddlers with hypovitaminosis D [ 25(OH)D < 20 ng/ml ] participated in the study . INTERVENTIONS Participants were assigned to one of three regimens : 2,000 IU oral vitamin D2 daily , 50,000 IU vitamin D2 weekly , or 2,000 IU vitamin D3 daily . Each was also prescribed elemental calcium ( 50 mg/kg.d ) . Infants received treatment for 6 wk . MAIN OUTCOME MEASURES Before and after treatment , serum measurements of 25(OH)D , PTH , calcium , and alkaline phosphatase were taken . RESULTS All treatments approximately tripled the 25(OH)D concentration . Preplanned comparisons were nonsignificant : daily vitamin D2 vs. weekly vitamin D2 ( 12 % difference in effect , P = 0.66 ) and daily D2 vs. daily D3 ( 7 % , P = 0.82 ) . The mean serum calcium change was small and similar in the three groups . There was no significant difference in PTH suppression . CONCLUSIONS Short-term vitamin D2 2,000 IU daily , vitamin D2 50,000 IU weekly , or vitamin D3 2,000 IU daily yield equivalent outcomes in the treatment of hypovitaminosis D among young children . Therefore , pediatric providers can individualize the treatment regimen for a given patient to ensure compliance , given that no difference in efficacy or safety was noted among these three common treatment regimens Vitamin D deficiency may have implication s for cardiovascular health . The purpose of this study was to determine the relationship of 25-hydroxyvitamin D ( 25[OH]D ) to cholesterol and lipoprotein particles and to determine whether increasing 25(OH)D through ultraviolet ( UV ) irradiation impacted on these parameters in healthy young men and women . This was a r and omized trial of 51 adults exposed to suberythemal doses of whole-body irradiation using UV lamps that emitted UV-A and UV-B radiation , compared with a control group , twice weekly for 12 weeks .  25-Hydroxyvitamin D , cholesterol , and lipoprotein subfractions were measured at baseline and after 12 weeks . There was a significant ( P < .03 ) positive association between 25(OH)D and apolipoprotein A-I ( Apo A-I ) and lipoprotein A-I ( Lp A-I ) . The ratio of low-density lipoprotein to high-density lipoprotein was significantly ( P < or = .044 ) negatively correlated with 25(OH)D levels . The levels of 25(OH)D increased significantly in the treated compared with control group ( P < .05 ) . Overall , there were no significant differences between the treated and control groups in any lipoproteins or apolipoproteins after administration of UV irradiation . Subgroup analysis for Apo A-II confined to those with 25(OH)D insufficiency ( 25[OH]D < 75 nmol/L [ 30 ng/mL ] ) revealed decreases in Apo A-II in the treated group and increases in the control group that were statistically significantly different between the groups ( P = .026 ) . We found a significant positive correlation between 25(OH)D and Apo A-I and Lp A-I and a significant negative correlation between 25(OH)D and the ratio of low-density lipoprotein to high-density lipoprotein . In those with vitamin D insufficiency , we found small decreases in Apo A-II in the treated relative to the control group . Overall , though , twice weekly exposure to UV radiation result ing in an increase in serum 25(OH)D had no significant impact on lipoprotein composition Background Despite Australia ’s sunny climate , low vitamin D levels are increasingly prevalent . Sun exposure is limited by long working hours , an increase in time spent indoors , and sun protection practice s , and there is limited dietary vitamin D fortification . While the importance of vitamin D for bone mineralization is well known , its role as a protective agent against chronic diseases , such as type 2 diabetes and cardiovascular disease , is less understood . Observational and limited intervention studies suggest that vitamin D might improve insulin sensitivity and secretion , mainly via its anti-inflammatory properties , thereby decreasing the risk of development and progression of type 2 diabetes . The primary aim of this trial is to investigate whether improved plasma concentrations of 25-hydroxyvitamin D ( 25(OH)D ) , obtained through vitamin D supplementation , will increase insulin sensitivity and insulin secretion . A secondary aim is to determine whether these relationships are mediated by a reduction in underlying sub clinical inflammation associated with obesity . Methods / Design Fifty overweight but otherwise healthy nondiabetic adults between 18 and 60 years old , with low vitamin D levels ( 25(OH)D < 50 nmol/l ) , will be r and omly assigned to intervention or placebo . At baseline , participants will undergo a medical review and anthropometric measurements , including dual X-ray absorptiometry , an intravenous glucose tolerance test , muscle and fat biopsies , a hyperinsulinemic euglycemic clamp  , and question naires assessing diet , physical activity , sun exposure , back and knee pain , and depression . The intervention group will receive a first dose of 100,000 IU followed by 4,000 IU vitamin D ( cholecalciferol ) daily , while the placebo group will receive apparently identical capsules , both for a period of 16 weeks . All measurements will be repeated at follow-up , with the primary outcome measure expressed as a change from baseline in insulin sensitivity and secretion for the intervention group compared with the placebo group . Secondary outcome measures will compare changes in anthropometry , cardiovascular risk factors , and inflammatory markers . Discussion The trial will provide much needed clinical evidence on the impact of vitamin D supplementation on insulin resistance and secretion and its underlying mechanisms , which are relevant for the prevention and management of type 2 diabetes . Trial registration Clinical trials.gov ID : NCT02112721 PURPOSE The most safe and effective dose of vitamin D supplementation for healthy adolescents is currently unknown . The aim of this study was to compare the efficacy of 200 IU versus 1,000 IU of daily vitamin D3 for supplementation in healthy adolescents with baseline vitamin D sufficiency . METHODS We conducted a double-blind , r and omized clinical trial . Fifty-six subjects , ages 11 - 19 years , with baseline vitamin D sufficiency  received 1,000 IU or 200 IU of daily vitamin D3 for 11 weeks . Compliance was assessed using MEMS6 Trackcaps and pill counts . RESULTS Fifty-three subjects completed the clinical trial . Subjects in the two treatment arms were similar in terms of age , race , gender , body mass index , and dietary calcium and vitamin D intake . Serum 25(OH)D level in the 200 IU treatment arm was 28.1 ± 6.2 ng/mL at baseline ( mean ± SD ) and 28.9 ± 7.0 ng/mL at follow-up . In the 1,000 IU treatment arm , 25(OH)D levels were 29.0 ± 7.3 and 30.1 ± 6.6 at baseline and follow-up , respectively . Mean change in 25(OH)D level did not differ significantly between treatment arms ( p = .87 ) , nor did mean change in parathyroid hormone , calcium , phosphate , bone turnover markers , fasting glucose , or fasting insulin . CONCLUSIONS In healthy adolescents with baseline vitamin D sufficiency , supplementation with vitamin D3 doses of 200 and 1,000 IU for 11 weeks did not increase serum 25(OH)D levels , with no significant difference observed between treatment arms Background / Aims : Vitamin D deficiency is highly prevalent in obese children , and obese children tend to respond poorly to vitamin D supplementation . The objective of the study was to compare the response to vitamin D3 supplementation ( 2,000 IU once daily 
    Output:
    
The prevalence of VDD was considered high in obese adolescents and their relationship with the  obesity  and related diseases was found in adolescents .
These findings forewarn of possible clinical repercussions in the health of the adolescents , foremost because of how essential vitamin D is to growth and development , and for its interaction with obesity and obesity-related diseases .
The worldwide rise in the obesity rate alongside the progressively increasing of vitamin D deficiency in adolescents is alarming .
This relationship of VDD with the obesity and related diseases was found in adolescents .
Vitamin D supplementation is considered promising measure to take with obese adolescents