Prospective study of vitamin D supplementation and rickets in China. Vitamin D supplementation and growth in urban Mongol school children: Results from two randomized clinical trials Plasma Vitamin D and 25OHD Responses of Young and Old Men to Supplementation with Vitamin D3 A dose–response study of vitamin D3 supplementation in healthy Chinese: a 5-arm randomized, placebo-controlled trial High-dose vitamin d intervention in infants--effects on vitamin d status, calcium homeostasis, and bone strength. A 16-week randomized clinical trial of 2000 international units daily vitamin D3 supplementation in black youth: 25-hydroxyvitamin D, adiposity, and arterial stiffness. A Double-Blind, Placebo Controlled, Randomized Trial to Assess the Impact of a Monthly Administration of 50,000 IU of Vitamin D3 for 6 Months on Serum Levels of 25-Hydroxyvitamin D in Healthy Young Adults A prospective study of serum 25-hydroxyvitamin d levels and mortality among African Americans and non-African Americans. Vitamin D status in relation to one-year risk of recurrent falling in older men and women. Body Size and Serum 25 Hydroxy Vitamin D Response to Oral Supplements in Healthy Older Adults Differences in vitamin D3 dosing regimens in a geriatric community-dwelling population. The Association between Pre-Treatment Serum 25-Hydroxyvitamin D and Survival in Newly Diagnosed Stage IV Prostate Cancer Environmental, personal, and genetic determinants of response to vitamin D supplementation in older adults. Vitamin D supplementation in young White and African American women. Plasma 25-Hydroxyvitamin D Levels and Risk of Incident Hypertension Serum 25-Hydroxyvitamin D Concentrations and Depressive Symptoms among Young Adult Men and Women Vitamin D insufficiency and health outcomes over 5 y in older women.
To determine whether amounts of vitamin D lower than recommended doses are effective in preventing rickets , 256 term infants from two northern and two southern cities in China were studied in a r and omized trial of vitamin D supplementation ( 100 , 200 , or 400 IU/day ) during the first 6 months of life . Cord blood and 6-month blood sample s were collected and radiographs were obtained at 3 to 5 days and at 6 months of age . Cord serum 25-hydroxyvitamin D concentrations were lower in the north than in the south ( 5 vs 14 ng/ml ( 12.5 vs 35.0 nmol/L ) ; p less than 0.01 ) . Wrist ossification centers were less likely to be present at birth in the northern children than in the southern children ( p = 0.009 ) and were more likely to be present in infants born in the fall who had higher cord serum concentrations of 25-hydroxyvitamin D ( p = 0.04 ) . Serum 25-hydroxyvitamin D concentrations were lower in northern children 6 months of age than in southern children ( p = 0.005 ) and were higher with an increasing supplemental dosage of vitamin D ( p less than 0.001 ) , particularly in infants in the north . None of the infants had rickets at 6 months of age . Because of the low serum 25-hydroxyvitamin D concentrations , especially among infants in the north , it may be prudent to supplement the diet with vitamin D at a dose of 400 IU/day Background Symptomatic vitamin D deficiency is associated with slowed growth in children . It is unknown whether vitamin D repletion in children with asymptomatic serum vitamin D deficiency can restore normal growth . Objective We tested the impact of vitamin D-supplementation on serum concentrations of 25-hydroxyvitamin D [ 25(OH)D ] and short-term growth in Mongol children , with very low serum vitamin D levels in winter . Design We conducted two r and omized , double-blind , placebo-controlled trials in urban school age children without clinical signs of rickets . The Supplementation Study was a 6-month intervention with an 800 IU vitamin D3 supplement daily , compared with placebo , in 113 children aged 12–15 years . A second study , the Fortification Study , was a 7-week intervention with 710 ml of whole milk fortified with 300 IU vitamin D3 daily , compared with unfortified milk , in 235 children aged 9–11 years . Results At winter baseline , children had low vitamin D levels , with a mean ( ±SD ) serum 25-hydroxyvitamin D [ 25(OH)D ] concentration of 7.3 ( ±3.9 ) ng/ml in the Supplementation Study and 7.5 ( ±3.8 ) ng/ml in the Fortification Study . The serum levels increased in both vitamin D groups — by 19.8 ( ±5.1 ) ng/ml in the Supplementation Study , and 19.7 ( ±6.1 ) ng/ml in the Fortification Study . Multivariable analysis showed a 0.9 ( ±0.3 SE ) cm greater increase in height in the vitamin-D treated children , compared to placebo treated children , in the 6-month Supplementation Study ( p = 0.003 ) . Although the children in the 7-week Fortification Study intervention arm grew 0.2 ( ±0.1 ) cm more , on average , than placebo children this difference was not statistically significant ( p = 0.2 ) . There were no significant effects of vitamin D supplements on differences in changes in weight or body mass index in either trial . For the Fortification Study , girls gained more weight than boys while taking vitamin D 3 ( p-value for interaction = 0.03 ) , but sex was not an effect modifier of the relationship between vitamin D3 and change in either height or BMI in either trial . Conclusions Correcting vitamin D deficiency in children with very low serum vitamin D levels using 800 IU of vitamin D3 daily for six months increased growth , at least in the short-term , whereas , in a shorter trial of 300 IU of D fortified milk daily for 7 weeks did not Objectives : This study was conducted to determine whether there are age differences in the plasma parent vitamin D and 25-hydroxyvitamin D ( 25OHD ) responses to eight weeks of supplementation with 20 μg/day of vitamin D3 . Methods : Twenty-five healthy young men ( age 18–35 ) and 25 healthy older men ( 62–79 ) were r and omly assigned to supplementation with 20 μg/day of vitamin D3 or to no intervention and followed for eight weeks . Plasma vitamin D3 was measured by high performance liquid chromatography and 25OHD was measured by competitive protein binding . Results : Both young and old men in the supplemented group had pronounced , rapid and similar increases in plasma vitamin D3 , whereas vitamin D3 concentrations were stable in the control group . By the end of the eight-week adaptation period , plasma vitamin D3 of young and old men had increased by 4.3 and 6.2 nmol/L respectively . In the supplemented group , mean 25OHD concentrations of both the young and old men increased during the study , and the magnitude of the change after eight weeks was nearly identical in the two age groups ( 22.5 and 22.1 nmol/L in the young and the old men , respectively ) . In the control group there was a modest decrease in 25OHD of both the young and old men . Conclusions : There appears to be no age-related impairment among men in the absorption or metabolism of 20 μg/day of vitamin D3 taken orally for at least eight weeks Abstract Purpose To determine the dose – response of vitamin D3 supplementation on serum 25-hydroxyvitamin D [ 25(OH)D ] among Chinese adults . Methods In this 5-arm , r and omized , double-blinded controlled trial , 76 healthy participants were assigned to orally administrate 0 , 400 , 800 , 1200 or 2000 IU/d of vitamin D3 for 16 weeks . Serum 25(OH)D , parathyroid hormone , calcium , biomarkers of liver and renal function were measured at multiple time points . Results The mean ( SD ) serum 25(OH)D at baseline was 31.6 ( 8.7 ) nmol/L , and the dose – response relationship was curvilinear with a plateau around 6 weeks for all doses . At week 16 , 25(OH)D was increased by 6.0 ( 6.5 ) , 21.7 ( 15.8 ) , 26.3 ( 12.6 ) , 32.0 ( 12.8 ) and 36.3 ( 26.0 ) nmol/L for 0 , 400 , 800 , 1200 and 2000 IU/d ( all P ≤ 0.002 ) , corresponding to approximately 19 , 53 , 67 , 77 and 80 % of reversion of vitamin D deficiency , respectively . Daily intake of 800 IU vitamin D3 reached a targeted 25(OH)D ≥ 30 nmol/L in at least 97.5 % of Chinese , but not a targeted 25(OH)D ≥ 50 nmol/L even with 2000 IU/d . Change of 25(OH)D was inversely associated with change of PTH concentration ( r = −0.39 , P < 0.001 ) after controlling for age and sex . No between-group differences were observed in terms of the change in serum calcium , alanine transaminase , aspartate aminotransferase , gamma-glutamyltransferase and creatinine ( P ≥ 0.22 ) . Conclusions Supplementation with 400 , 800 , 1200 or 2000 IU/d vitamin D could improve the vitamin D deficiency with various degrees . Whether 2000 IU/d vitamin D3 would generate a better result without side effect requires more studies with larger sample s in future CONTEXT Guidelines in Finl and recommend 10 μg of vitamin D3 daily for all infants . Recent observations suggest that this may be insufficient to maintain optimal serum 25-hydroxyvitamin D ( S-25-OHD ) . OBJECTIVE The aim of the study was to evaluate effects of various vitamin D doses and determine a dose ensuring S-25-OHD of at least 80 nmol/liter in infants without signs of vitamin D excess . DESIGN We conducted a r and omized double-blind intervention study . Cord blood was obtained at birth for S-25-OHD ; 113 infants were r and omized to receive vitamin D3 10 , 30 , or 40 μg/d from age 2 wk to 3 months . SETTING An investigator-initiated study was performed in a single maternity hospital in Helsinki , Finl and . MAIN OUTCOME MEASURES S-25-OHD , calcium homeostasis , and skeletal characteristics were evaluated with peripheral quantitative computed tomography at age 3 months . RESULTS Baseline S-25-OHD was similar in all three groups ( median , 53 nmol/liter ) . At 3 months , the mean S-25-OHD values were 88 , 124 , and 153 nmol/liter , and the minimum values were 46 , 57 , and 86 nmol/liter in the groups receiving 10 , 30 , and 40 μg ( ANOVA ; P < 0.001 ) . No hypercalcemia occurred ; plasma calcium , serum PTH , and urine calcium excretion was similar between the groups . Peripheral quantitative computed tomography showed a trend toward larger tibial total bone and cortical bone area with higher vitamin D doses . CONCLUSION Vitamin D3 supplementation with up to 40 μg/d from age 2 wk to 3 months was safe and caused no hypercalcemia or hypercalciuria . The 40-μg dose maintained S-25-OHD above 80 nmol/liter in all infants . More extensive and longer intervention studies are necessary to assess long-term effects CONTEXT Vitamin D insufficiency/deficiency is commonly observed in black youth . OBJECTIVE The aim was to determine 25-hydroxyvitamin D [ 25(OH)D ] in response to 2000 IU vitamin D supplementation over time ; to evaluate the relation between 25(OH)D concentrations and total body fat mass by dual-energy x-ray absorptiometry ; and to determine whether vitamin D supplementation improves arterial stiffness measured by pulse wave velocity ( PWV ) . DESIGN We conducted a r and omized , blinded , controlled clinical trial . SETTING AND PARTICIPANTS Forty-nine normotensive black boys and girls , aged 16.3 ± 1.4 yr , were r and omly assigned to either the control group ( 400 IU/d ; n = 24 ) or the experimental group ( 2000 IU/d ; n = 25 ) . RESULTS Plasma 25(OH)D values at baseline and at 4 , 8 , and 16 wk were 34.0 ± 10.6 , 44.9 ± 9.4 , 51.2 ± 11.1 , and 59.8 ± 18.2 nmol/liter , respectively , for the control group ; and 33.1 ± 8.7 , 55.0 ± 11.8 , 70.9 ± 22.0 , and 85.7 ± 30.1 nmol/liter , respectively , for the experimental group . The experimental group vs. the control group reached significantly higher 25(OH)D concentrations at 8 and 16 wk , respectively . Partial correlation analyses indicated that total body fat mass at baseline was significantly and inversely associated with 25(OH)D concentrations in response to the 2000-IU supplement across time . Furthermore , carotid-femoral PWV increased from baseline ( 5.38 ± 0.53 m/sec ) to posttest ( 5.71 ± 0.75 m/sec ) in the control group ( P = 0.016 ) , whereas in the experimental group carotid-femoral PWV decreased from baseline ( 5.41 ± 0.73 m/sec ) to posttest ( 5.33 ± 0.79 m/sec ) ( P = 0.031 ) . CONCLUSION Daily 2000 IU vitamin D supplementation may be effective in optimizing vitamin D status and counteracting the progression of aortic stiffness in black youth . Plasma 25(OH)D concentrations in response to the 2000 IU/d supplementation are negatively modulated by adiposity In this double blind , unicentre , r and omized , placebo controlled study , we evaluated the changes in 25-hydroxyvitamin D ( 25(OH)D ) serum levels in 150 young Belgian adults ( 18–30 years ) , monthly supplemented with 50,000 IU of vitamin D ( VTD ) or placebo for 6 months , from November 2010 to May 2011 . At T0 , 30 % of the population presented 25(OH)D serum levels below 20 ng/mL. In the VTD-treated group , mean serum levels increased from 21.2 ± 8.2 to 30.6 ± 8.8 ng/mL ( P < 0.001 ) at T3mo and to 36.0 ± 9.2 ng/mL ( P < 0.001 ) at T6mo . Despite documented VTD intake , no changes in serum levels were , however , observed in 10 % of the treated group . In the placebo group , mean 25(OH)D serum levels decreased from 22.8 ± 8.5 to 14.0 ± 6.9 ng/mL at T3mo ( P < 0.001 ) but returned to values not significantly different from those observed at T0 ( 23.5 ± 8.6 ng/mL ) at T6mo . No difference between serum calcium levels was observed between the groups throughout the study . In conclusion , monthly supplementation with 50,000 UI of VTD in winter can warrant serum 25(OH)D levels above 20 ng/mL in 96.2 % of those healthy young adults without inducing unacceptably high 25(OH)D concentration . This supplementation is safe and may be proposed without 25(OH)D testing The beneficial biologic effects attributed to vitamin D suggest a potential to influence overall mortality . Evidence addressing this hypothesis is limited , especially for African Americans who have a high prevalence of vitamin D insufficiency . The authors conducted a nested case-control study within the prospect i ve Southern Community Cohort Study to relate baseline serum levels of 25-hydroxyvitamin D ( 25(OH)D ) with subsequent mortality .  Cases were 1,852 participants who enrolled from 2002 to 2009 and died > 12 months postenrollment . Controls ( n = 1,852 ) were matched on race , sex , age , enrollment site , and blood collection date . The odds ratios for quartile 1 ( < 10.18 ng/mL ) versus quartile 4 ( > 21.64 ng/mL ) levels of 25(OH)D were 1.60 ( 95 % confidence interval ( CI ) : 1.20 , 2.14 ) for African Americans and 2.11 ( 95 % CI : 1.39 , 3.21 ) for non-African Americans . The effects were strongest for circulatory disease death , where quartile 1 versus quartile 4 odds ratios were 2.53 ( 95 % CI : 1.44 , 4.46 ) and 3.25 ( 95 % CI : 1.33 , 7.93 ) for African Americans and non-African Americans , respectively . The estimated odds of total mortality were minimized in the 25(OH)D range of 35 - 40 ng/mL. These findings provide support for the hypothesis that vitamin D status may have an important influence on mortality for both African Americans and non-African Americans BACKGROUND Falls frequently occur in the elderly and are a major cause of morbidity and mortality . OBJECTIVE The objective of the study was to prospect ively investigate the association between serum 25-hydroxyvitamin D [ 25(OH)D ] levels and risk of recurrent falling  in older men and women . DESIGN This was a prospect i ve cohort study . SETTING An age- and sex-stratified r and om sample of the Dutch older population was determined . SUBJECTS Subjects included 1231 men and women ( aged 65 yr and older ) participating in the Longitudinal Aging Study Amsterdam . MEASUREMENTS Baseline serum 25(OH)D was determined by a competitive protein binding assay . During 1 yr , falls were prospect ively recorded by means of a fall calendar . RESULTS Low 25(OH)D ( < 10 ng/ml ) was associated with an increased risk of falling . After adjustment for age , sex , education level , region , season , physical activity , smoking , and alcohol intake , the odds ratios ( 95 % confidence interval ) were 1.78 ( 1.06 - 2.99 ) for subjects who experienced two falls or more as compared with those who did not fall or fell once and 2.23 ( 1.17 - 4.25 ) for subjects who fell three or more times as compared with those who fell two times or less . There was a statistically significant effect modification by age , and stratified analyses ( < 75 and > or = 75 yr ) showed that the associations were particularly strong in the younger age group ; the odds ratios ( 95 % confidence interval ) were 5.21 ( 2.03 - 13.40 ) for two falls or more and 4.96 ( 1.52 - 16.23 ) for three falls or more . CONCLUSIONS Poor vitamin D status is independently associated with an increased risk of falling  in the elderly , particularly in those aged 65 - 75 yr Background : Vitamin D insufficiency is prevalent in the northeast United States . Since vitamin D insufficiency is readily amenable to supplementation , it is important to underst and what factors are associated with serum 25 hydroxy vitamin D ( 25(OH)D ) response to vitamin D supplementation . Objective : In this study we examined the association of serum 25(OH)D response to vitamin D supplementation with body size in a population of elderly subjects . Methods : 257 healthy , ambulatory men and women 65 years of age or older were r and omly assigned to treatment with either 700 IU/day ( 17.5 μg/d ) of supplemental vitamin D3 and 500 mg/day ( 12.5 mmol/d ) of supplemental calcium , or to placebo . Results : In multivariate regression analyses , after adjusting for baseline 25(OH)D , season , and sex , we found change in 25(OH)D to be inversely associated with baseline BMI ( p = 0.01 ) in subjects treated with supplements for one year . Change in 25(OH)D was also negatively associated with other baseline anthropometric measurements in these subjects . Conclusion : Our study implies that body size should be taken into account when estimating the amount of vitamin D intake needed to raise 25(OH)D to the desired level OBJECTIVE The adequate dose of vitamin D supplementation for community-dwelling elderly people has not been thoroughly investigated . This study aims to determine the efficacy of a low-dose and a higher dose of vitamin D3 in maintaining 25-hydroxyvitamin D [ 25(OH)D ] levels at or above 30 ng/mL. METHODS This was a single site , double-blind , r and omized exploratory clinical trial that enrolled adults 65 years of age and older . Within strata of baseline 25(OH)D levels ( < 30 versus ≥ 30 ng/mL ) subjects were r and omized in a 1:2 ratio to receive either 400 or 2,000 IU vitamin D3 daily for 6 months . The main outcome measures were changes in serum 25(OH)D levels according to baseline 25(OH)D levels and dose of vitamin D3 . RESULTS At baseline , 41 of 105 participants ( 39 % ) had low 25(OH)D levels ( < 30 ng/mL ) . After 6 months of vitamin D3 supplementation , 21 of 32 participants ( 66 % ) receiving 400 IU and 14 of 59 participants ( 24 % ) receiving 2,000 IU of vitamin D3 still had low 25(OH)D levels . The largest increases in serum 25(OH)D levels were observed in subjects with baseline levels < 30 ng/mL who received 2,000 IU of vitamin D daily . CONCLUSION Regardless of baseline 25(OH)D level , in persons 65 years of age and older , 6-month vitamin D3 supplementation with 400 IU daily result ed in low 25(OH)D in most individuals , while 2,000 IU daily maintained 25(OH)D levels within an acceptable range in most people on this regimen Background / Aims Emerging evidence in the literature suggests a positive association between serum 25-hydroxyvitamin D [ 25(OH)D ] , a st and ard indicator of vitamin D status , and survival in certain types of cancer . We investigated this relationship in newly diagnosed stage IV prostate cancer patients . Methods A consecutive cohort of 125 newly diagnosed stage IV prostate cancer patients underwent a baseline serum 25(OH)D evaluation prior to receiving any treatment at our institution between January 2008 and December 2011 . We used the vitamin D categories of “ deficient ( < 20 ng/ml ) ” , “ insufficient ( 20 to 32 ng/ml ) ” , and “ sufficient ( > 32 ng/ml ) ” . Cox regression was used to evaluate the prognostic significance of serum 25(OH)D after adjusting for relevant confounders . Results Mean age at diagnosis was 60 years . Of the 125 patients , 32 ( 25.6 % ) were deficient , 49 ( 39.2 % ) were insufficient and 44 ( 35.2 % ) were sufficient in vitamin D at the time of diagnosis . The median survival in deficient , insufficient and sufficient cohorts was 47.8 , 44.0 and 52.6 months respectively ( p = 0.60 ) . On univariate analysis , four variables demonstrated a statistically significant association with survival : nutritional status , bone metastasis , corrected serum calcium and serum albumin ( p<0.05 for all ) . On multivariate analysis , five variables demonstrated statistically significant associations with survival : hospital location , age , bone metastasis , serum albumin and corrected serum calcium ( p<0.05 for all ) . Serum vitamin D status was not significant on either univariate or multivariate analysis . Conclusion Contrary to previously published research , we found no significant association between pre-treatment serum 25(OH)D and survival in newly diagnosed stage IV prostate cancer patients . The lack of a significant association between serum vitamin D and survival in our study could perhaps be due to the fact that the disease was far too advanced in our patients for vitamin D levels to have any impact on prognosis CONTEXT AND OBJECTIVE Suboptimal vitamin D status can be corrected by vitamin D supplementation , but individual responses to supplementation vary . We aim ed to examine genetic and nongenetic determinants of change in serum 25-hydroxyvitamin D ( 25(OH)D ) after supplementation . DESIGN AND PARTICIPANTS We used data from a pilot r and omized controlled trial in which 644 adults aged 60 to 84 years were r and omly assigned to monthly doses of placebo , 30 000 IU , or 60 000 IU vitamin D3 for 12 months . Baseline characteristics were obtained from a self-administered question naire . Eighty-eight single-nucleotide polymorphisms ( SNPs ) in 41 c and i date genes were genotyped using Sequenom MassArray technology . Serum 25(OH)D levels before and after the intervention were measured using the Diasorin Liaison platform immunoassay . We used linear regression models to examine associations between genetic and nongenetic factors and change in serum 25(OH)D levels . RESULTS Supplement dose and baseline 25(OH)D level explained 24 % of the variability in response to supplementation . Body mass index , self-reported health status , and ambient UV radiation made a small additional contribution . SNPs in CYP2R1 , IRF4 , MC1R , CYP27B1 , VDR , TYRP1 , MCM6 , and HERC2 were associated with change in 25(OH)D level , although only CYP2R1 was significant after adjustment for multiple testing . Models including SNPs explained a similar proportion of variability in response to supplementation as models that included personal and environmental factors . CONCLUSION Stepwise regression analyses suggest that genetic variability may be associated with response to supplementation , perhaps suggesting that some people might need higher doses to reach optimal 25(OH)D levels or that there is variability in the physiologically normal level of There is limited information on the effects of vitamin D on serum 25 hydroxyvitamin D ( 25OHD ) in young people and none on African Americans . The main objective of this trial was to measure the effect of different doses of vitamin D3 on serum 25OHD and serum parathyroid hormone ( PTH ) in young women with vitamin D insufficiency ( serum 25OHD ≤ 20 ng/mL ( 50 nmol/L ) . A r and omized double-blind placebo-controlled trial of vitamin D3 was conducted in young white and African American women , age 25 to 45 years . A total of 198 healthy white ( 60 % ) and African American ( 40 % ) women were r and omly assigned to placebo , or to 400 , 800 , 1600 , or 2400 IU of vitamin D3 daily . Calcium supplements were added to maintain a total calcium intake of 1000 to 1200 mg daily . The primary outcomes of the study were the final serum 25OHD and PTH levels at 12 months . The absolute increase in serum 25OHD with 400 , 800 , 1600 , and 2400 IU of vitamin D daily was slightly greater in African American women than in white women . On the highest dose of 2400 IU/d , the mixed model predicted that mean 25OHD increased from baseline 12.4 ng/mL ( 95 % confidence interval [ CI ] , 9.2 - 15.7 ) to 43.2 ng/mL ( 95 % CI , 38.2 - 48.1 ) in African American women and from 15.0 ng/mL ( 95 % CI , 12.3 - 17.6 ) to 39.1 ng/mL ( 95 % CI , 36.2 - 42.0 ) in white women . There was no significant effect  of vitamin D dose on serum PTH in either race but there was a significant inverse relationship between final serum PTH and serum 25OHD . Serum 25OHD exceeded 20 ng/mL in 97.5 % of whites on the 400 IU/d dose and between 800 and 1600 IU/d for African Americans . The recommended dietary allowance ( RDA ) suggested by the Institute of Medicine for young people is 600 IU daily . The increase in serum 25OHD  after vitamin D supplementation was similar in young and old , and in white and African American women Hydroxylation of 25(OH)D to 1,25-dihydroxyvitamin D and signaling through the vitamin D receptor occur in various tissues not traditionally involved in calcium homeostasis . Laboratory studies indicate that 1,25-dihydroxyvitamin D suppresses renin expression and vascular smooth muscle cell proliferation ; clinical studies demonstrate an inverse association between ultraviolet radiation , a surrogate marker for vitamin D synthesis , and blood pressure . We prospect ively studied the independent association between measured plasma 25-hydroxyvitamin D [ 25(OH)D ] levels and  risk of incident hypertension  and also the association between predicted plasma 25(OH)D levels and risk of incident hypertension .  Two prospect i ve cohort studies including 613 men from the Health Professionals ’ Follow-Up Study and 1198 women from the Nurses ’ Health Study with measured 25(OH)D levels were followed for 4 to 8 years . In addition , 2 prospect i ve cohort studies including 38 388 men and 77 531 women with predicted 25(OH)D levels were followed for 16 to 18 years . During 4 years of follow-up , the multivariable relative risk of incident hypertension among men whose measured plasma 25(OH)D levels were < 15 ng/mL ( ie , vitamin D deficiency ) compared with those whose levels were ≥30 ng/mL was 6.13 ( 95 % confidence interval [ CI ] : 1.00 to 37.8 ) . Among women , the same comparison yielded a relative risk of 2.67 ( 95 % CI : 1.05 to 6.79 ) . The pooled relative risk combining men and women with measured 25(OH)D levels using the r and om-effects model was 3.18 ( 95 % CI : 1.39 to 7.29 ) . Using predicted 25(OH)D levels in the larger cohorts , the multivariable relative risks comparing the lowest to highest deciles were 2.31 ( 95 % CI : 2.03 to 2.63 ) in men and 1.57 ( 95 % CI : 1.44 to 1.72 ) in women . Plasma 25(OH)D levels are inversely associated with risk of incident hypertension There has been an increased interest in the role of vitamin D in depression ; however , there have been few studies conducted in younger population groups . Our aim was to investigate the association between vitamin D status and depressive symptoms in a non- clinical young adult sample living in Dunedin , New Zeal and . A cross-sectional sample of 615 young adults completed a question naire including demographics and the  Centre  for Epidemiological Studies Depression Scale ( CES-D ) . Height , weight and a blood sample for 25-hydroxyvitamin D [ 25(OH)D ] was obtained . Serum 25(OH)D was used to predict depression scores , adjusting for potential confounders including time spent outdoors for 13 consecutive days , BMI , age , sex and ethnicity . Prevalence of low vitamin D was high even in this age group , and serum 25(OH)D was negatively associated with depression symptoms before and after adjustment . When investigating the relationship between the presence versus absence of depressive symptoms and quartiles of 25(OH)D , participants in the lowest quartile were more likely to report depressive symptoms compared with those in the highest quartile . Although our findings suggest that vitamin D is a predictor of depression symptomatology , even when controlling for time spent outdoors , a r and omised controlled trial in this young adult target group is needed to confirm the association BACKGROUND Vitamin D insufficiency was shown to be associated with adverse musculoskeletal and nonskeletal outcomes in numerous observational studies . However , some studies did not control for confounding factors such as age or seasonal variation of 25-hydroxyvitamin D [ 25(OH)D ] . OBJECTIVE We sought to determine the effect of vitamin D status on health outcomes . DESIGN Healthy community-dwelling women ( n = 1471 ) with a mean age of 74 y were followed in a 5-y trial of calcium supplementation .  25(OH)D was measured at baseline in all women .  Skeletal and nonskeletal outcomes were evaluated according to seasonally adjusted vitamin D status at baseline . RESULTS Fifty percent of women had a seasonally adjusted 25(OH)D concentration < 50 nmol/L. These women were significantly older , heavier , and less physically active and had more comorbidities than women with a seasonally adjusted 25(OH)D concentration > or = 50 nmol/L. Women with a seasonally adjusted 25(OH)D concentration < 50 nmol/L had an increased incidence of stroke and cardiovascular events that did not persist after adjustment for between-group differences in age or comorbidities . Women with a seasonally adjusted 25(OH)D concentration < 50 nmol/L were not at increased risk of adverse consequences for any musculoskeletal outcome , including fracture , falls , bone density , or grip strength or any nonskeletal outcomes , including death , myocardial infa rct ion , cancer , heart failure , diabetes , or adverse changes in blood pressure , weight , body composition , cholesterol , or glucose . CONCLUSIONS Vitamin D insufficiency is more common in older , frailer women . Community-dwelling older women with a seasonally adjusted 25(OH)D concentration < 50 nmol/L were not at risk of adverse outcomes over 5 y after control for comorbidities . R and omized placebo-controlled trials are needed to determine whether vitamin D supplementation in individuals with vitamin D insufficiency influences health outcomes . This trial was registered at www.anzctr.org.au as ACTRN 012605000242628
Dietary recommendations and r and omized trials on vitamin D supplementation should evaluate whether increases in circulating 25-hydroxyvitamin D levels match expectations -- for instance , the average increases obtained by trials on vitamin D3 without concomitant calcium supplements
CONTEXT Few studies in subjects over 50 yr of age have evaluated the influence of variable doses of vitamin D supplementation on serum 25-hydroxyvitamin D levels .
OBJECTIVE We performed a meta- analysis of changes in circulating 25-hydroxyvitamin D level associated with vitamin D supplementation in Caucasian subjects over 50 yr old .