A Treatment Trial of Vitamin D Supplementation in Breast-fed Infants: Universal Supplementation Is Not Necessary for Rickets Prevention in Southern Louisiana Prospective study of vitamin D supplementation and rickets in China. Vitamin-D-deficiency rickets in Kuwait: the prevalence of a preventable disease. Double Blind Study on the Need for Vitamin D Supplementation in Prepubertal Children Comparisons of oral calcium, high dose vitamin D and a combination of these in the treatment of nutritional rickets in children. A comparison of calcium, vitamin D, or both for nutritional rickets in Nigerian children. Vitamin D supplementation and growth in urban Mongol school children: Results from two randomized clinical trials Vitamin D supplementation in breastfed infants from Montréal, Canada: 25-hydroxyvitamin D and bone health effects from a follow-up study at 3 years of age DO IT Trial: vitamin D Outcomes and Interventions in Toddlers – a TARGet Kids! randomized controlled trial High-dose vitamin d intervention in infants--effects on vitamin d status, calcium homeostasis, and bone strength. Effect of different dosages of oral vitamin D supplementation on vitamin D status in healthy, breastfed infants: a randomized trial. Randomised controlled trial of daily versus stoss vitamin D therapy in Aboriginal children. Prevention of vitamin D deficiency in children following cardiac surgery: study protocol for a randomized controlled trial Vitamin D fortification of growing up milk prevents decrease of serum 25-hydroxyvitamin D concentrations during winter: a clinical intervention study in Germany Vitamin D Is a Major Determinant of Bone Mineral Density at School Age Randomized study of sunshine exposure and serum 25-OHD in breast-fed infants in Beijing, China. [Prophylaxis of vitamin D deficiency in hypothyroidism in the newborn infant].
This study was conducted to determine if vitamin D supplementation is required to prevent rickets in breast-fed infants . Breast-feeding rates are increasing , and there are concerns about whether the vitamin D content of breast milk is sufficient . There are a few treatment trials of vitamin D supplementation in breast-fed infants ; these were conducted in northern climates . The authors therefore performed a prospect i ve clinical trial comparing vitamin D supplementation with placebo as control in southern Louisiana . Blood sample s and question naires were collected at birth , 2 , 4 , and 6 months of age . There were no cases of rickets observed , and no differences in alkaline phosphatase levels between groups . Thus , there was no evidence that vitamin D supplementation reduced rickets risk in the authors ’ study population . This suggests that the current recommendations for universal vitamin D supplementation of breast-fed infants throughout the United States may need to be revised 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 Two hundred and fifty children with clinical , biochemical and radiological evidence of vitamin-D-deficiency rickets were studied over a period of 5 years . Their ages ranged from 1 month to 2 years . Breastfed infants formed 63 % of total cases . Intramuscular therapy with vitamin D in a dose of 600,000 IU , deep intramuscular , proved to be safe and effective . In contrast , oral vitamin D did not provide such satisfactory results , presumably owing to poor patient/parental compliance . This report reveals that vitamin-D-deficieny rickets is common in Kuwait in spite of abundant sunlight all through the year because children are wrapped up and kept indoors . Insufficient intake of vitamin D is another important factor in the pathogenesis of vitamin-D-deficiency rickets in Kuwait ABSTRACT . Fifty‐one healthy prepubertal schoolchildren were followed for 13 months in a double blind study . Twenty‐four of them were supplemented with 400 IU of vitamin D2 5–7 times weekly , while 27 received a placebo . The children were examined in winter both at the beginning and at the end of the study , and in the middle of the study in autumn . Mean 25‐hydroxyvitamin D levels in the supplemented group were significantly higher than those in the placebo group both in autumn and in winter , when the study ended . The vitamin D supplementation did not , however , affect other vitamin D metabolites , serum calcium , albumin , inorganic phosphorus , parathyroid hormone concentrations or alkaline phosphatase activity . Moreover , the supplementation caused no alterations in the weight or height gain or bone mineral content of the distal radius of the children , and thus sub clinical rickets could not be shown Nutritional rickets remains a common child health problem in Turkey and many other developing countries . Although vitamin D deficiency is accepted as the basic problem underlying the disease , others postulate that a deficiency of dietary calcium , rather than vitamin D , is often responsible for the nutritional rickets in sunny countries . We conducted a placebo-controlled study to determine the best treatment regimen for nutritional rickets in children residing in lower socioeconomic regions of a sunny city , Istanbul . Forty-two infants ( aged 6 - 30 months ) with rickets were divided into three groups and included in the study . In a r and omized fashion vitamin D ( 300 000 units , intramuscularly ) , calcium lactate ( 3 g daily ) or a combination of vitamin D and calcium were given to the children . Alkaline phosphatase , calcium , albumin , ionized calcium and phosphorus levels were measured each week . X-ray examinations of the left wrist and left knee were undertaken at the beginning of the study and were repeated at the 2nd and 4th weeks and were scored in order to assess the response to treatment . Treatment produced an increase in serum calcium and a decrease in alkaline phosphatase concentration in all three groups , but the most important increase was reached in the vitamin D plus calcium group . We conclude that vitamin D deficiency appears to be the primary etiologic factor of rickets in our study group , but a better response to treatment with vitamin D or in combination with calcium was obtained than to treatment with calcium alone BACKGROUND Nutritional rickets remains prevalent in many tropical countries despite the fact that such countries have ample sunlight . Some postulate that a deficiency of dietary calcium , rather than vitamin D , is often responsible for rickets after infancy . METHODS We enrolled 123 Nigerian children ( median age , 46 months ) with rickets in a r and omized , double-blind , controlled trial of 24 weeks of treatment with vitamin D ( 600,000 U intramuscularly at enrollment and at 12 weeks ) , calcium ( 1000 mg daily ) , or a combination of vitamin D and calcium . We compared the calcium intake of the children at enrollment with that of control children without rickets who were matched for sex , age , and weight . We measured serum calcium and alkaline phosphatase and used a 10-point radiographic score to assess the response to treatment at 24 weeks . RESULTS The daily dietary calcium intake was low in the children with rickets and the control children ( median , 203 mg and 196 mg , respectively ; P=0.64 ) . Treatment produced a smaller increase in the mean ( + /-SD ) serum calcium concentration in the vitamin D group ( from 7.8+/-0.8 mg per deciliter [ 2.0+/-0.2 mmol per liter ] at base line to 8.3+/-0.7 mg per deciliter [ 2.1+/-0.2 mmol per liter ] at 24 weeks ) than in the calcium group ( from 7.5+/-0.8 [ 1.9+/-0.2 mmol per liter ] to 9.0+/-0.6 mg per deciliter [ 2.2+/-0.2 mmol per liter ] , P<0.001 ) or the combination-therapy group ( from 7.7+/-1.0 [ 1.9+/-0.25 mmol per liter ] to 9.1+/-0.6 mg per deciliter [ 2.3+/-0.2 mmol per liter ] , P<0.001 ) . A greater proportion of children in the calcium and combination-therapy groups than in the vitamin D group reached the combined end point of a serum alkaline phosphatase concentration of 350 U per liter or less and radiographic evidence of nearly complete healing of rickets ( 61 percent , 58 percent , and 19 percent , respectively ; P<0.001 ) . CONCLUSIONS Nigerian children with rickets have a low intake of calcium and have a better response to treatment with calcium alone or in combination with vitamin D than to treatment with vitamin D alone 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 Summary Whether infant vitamin D supplementation may have long-term bone benefits is unclear . In this study , breastfed infants who received vitamin dosages greater than 400 IU/day did not have higher bone mineralization at 3 years . This study provides important data to inform pediatric public health recommendations for vitamin D. Introduction North American health agencies recommend breastfed infants should be supplemented with 400 IU of vitamin D/day to support bone health . Few studies examined the long-term benefits of early life vitamin D supplementation on bone mineralization . The objective of this study was to determine if a dose-response relationship exists between infant vitamin D supplementation , vitamin D status , and bone outcomes at 3 years of age . Methods This was a double-blind r and omized trial of 132 , 1-month-old healthy , breastfed infants from Montréal , Canada , between 2007 and 2010 . In this longitudinal analysis , 87 infants ( 66 % ) returned for follow-up at 3 years of age , between 2010 and 2013 . At 1 month of age , participants were r and omly assigned to receive oral cholecalciferol ( vitamin D3 ) supplements of 400 , 800 , 1200 , or 1600 IU/day until 12 months of age . Lumbar spine vertebrae 1–4 ( LS ) bone mineral density ( BMD ) , LS and whole body bone mineral content ( BMC ) , and mineral accretion were measured by dual-energy x-ray absorptiometry at 3 years . Results At follow-up , the treatment groups were similar in terms of diet , sun exposure , and demographics . There were no significant differences among the groups in LS or whole body BMC , BMD , or accretion . Although , 25(OH)D concentrations were not different among the groups , higher doses ( 1200 and 1600 IU/day ) achieved higher 25(OH)D area under the curve from 1 to 36 months vs. 400 IU/day . Conclusions This is the first longitudinal follow-up of an infant vitamin D dose-response study which examines bone mineralization at 3 years of age . Dosages higher than 400 IU/day do not appear to provide additional benefits to the bone at follow-up . Larger studies with more ethnically diverse groups are needed to confirm these results Background Vitamin D levels are alarmingly low ( < 75 nmol/L ) in 65 - 70 % of North American children older than 1 year . An increased risk of viral upper respiratory tract infections ( URTI ) , asthma-related hospitalizations and use of anti-inflammatory medication have all been linked with low vitamin D. No study has determined whether wintertime vitamin D supplementation can reduce the risk of URTI and asthma exacerbations , two of the most common and costly illnesses of early childhood . The objectives of this study are : 1 ) to compare the effect of ‘ high dose ’ ( 2000 IU/day ) vs. ‘ st and ard dose ’ ( 400 IU/day ) vitamin D supplementation in achieving reductions in laboratory confirmed URTI and asthma exacerbations during the winter in preschool-aged Canadian children ; and 2 ) to assess the effect of ‘ high dose ’ vitamin D supplementation on vitamin D serum levels and specific viruses that cause URTI . Methods / Design This study is a pragmatic r and omized controlled trial . Over 4 successive winters we will recruit 750 healthy children 1–5 years of age . Participating physicians are part of a primary healthcare research network called TARGet Kids!. Children will be r and omized to the ‘ st and ard dose ’ or ‘ high dose ’ oral supplemental vitamin D for a minimum of 4 months ( 200 children per group ) . Parents will obtain a nasal swab from their child with each URTI , report the number of asthma exacerbations and complete symptom checklists . Unscheduled physician visits for URTIs and asthma exacerbations will be recorded . By May , a blood sample will be drawn to determine vitamin D serum levels . The primary analysis will be a comparison of URTI rate between study groups using a Poisson regression model . Secondary analyses will compare  vitamin D serum levels , asthma exacerbations and the frequency of specific viral agents between groups . Discussion Identifying whether vitamin D supplementation of preschoolers can reduce wintertime viral URTIs and asthma exacerbations and what dose is optimal may reduce population wide morbidity and associated health care and societal costs . This information will assist in determining practice and health policy recommendations related to vitamin D supplementation in healthy Canadian preschoolers 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 IMPORTANCE Vitamin D supplementation in infancy is required to support healthy bone mineral accretion . A supplement of 400 IU of vitamin D per day is thought to support plasma 25-hydroxyvitamin D ( 25[OH]D ) concentrations between 40 and 50 nmol/L ; some advocate 75 to 150 nmol/L for bone health . OBJECTIVE To investigate the efficacy of different dosages of vitamin D in supporting 25(OH)D concentrations in infants . DESIGN , SETTING , AND PARTICIPANTS Double-blind r and omized clinical trial conducted among 132 one-month-old healthy , term , breastfed infants from Montréal , Québec , Canada , between March 2007 and August 2010 . Infants were followed up for 11 months ending August 2011 ( 74 % completed study ) . INTERVENTION Participants were r and omly assigned to receive oral cholecalciferol ( vitamin D3 ) supplements of 400 IU/d ( n=39 ) , 800 IU/d ( n=39 ) , 1200 IU/d ( n=38 ) , or 1600 IU/d ( n=16 ) . MAIN OUTCOMES AND MEASURES The primary outcome was a plasma 25(OH)D concentration of 75 nmol/L or greater in 97.5 % of infants at 3 months . Secondary outcomes included 25(OH)D concentrations of 75 nmol/L or greater in 97.5 % of infants at 6 , 9 , and 12 months ; 25(OH)D concentrations of 50 nmol/L or greater across all times ; growth ; and whole body and regional bone mineral content . Data were analyzed by intention to treat using available data , logistic regression , and mixed-model analysis of variance . RESULTS By 3 months , 55 % ( 95 % CI , 38%-72 % ) of infants in the 400-IU/d group achieved a 25(OH)D concentration of 75 nmol/L or greater vs 81%(95 % CI , 65%-91 % ) in the 800-IU/d group , 92 % ( 95 % CI , 77%-98 % ) in the 1200-IU/d group , and 100 % in the 1600-IU/d group . This concentration was not sustained in 97.5 % of infants at 12 months in any of the groups . The 1600-IU/d dosage was discontinued prematurely because of elevated plasma 25(OH)D concentrations . All dosages established 25(OH)D concentrations of 50 nmol/L or greater in 97 % ( 95 % CI , 94%-100 % ) of infants at 3 months and sustained this in 98 % ( 95 % CI , 94%-100 % ) to 12 months . Growth and bone mineral content did not differ by dosage . CONCLUSIONS AND RELEVANCE Among healthy , term , breastfed infants , only a vitamin D supplement dosage of 1600 IU/d ( but not dosages of 400 , 800 , or 1200 IU/d ) increased plasma 25(OH)D concentration to 75 nmol/L or greater in 97.5 % of infants at 3 months . However , this dosage increased 25(OH)D concentrations to levels that have been associated with hypercalcemia . TRIAL REGISTRATION clinical trials.gov Identifier : NCT00381914 AIM The prevalence of vitamin D deficiency has risen in countries with a high ultraviolet index and sunny environment such as Australia . There is lack of information on vitamin D status and best possible therapy in Australian Aboriginal children . We aim to ( i ) describe the vitamin D status in an opportunistic sample of Aboriginal children in Western Australia and ( ii ) compare the efficacy of oral daily vitamin D with oral stoss vitamin D therapy in this sample . METHOD Participants were recruited from a metropolitan area ( 31 ' S ) and a rural area ( 17 ' S ) . Those with a 25(OH)D level less than 78 nmol/L were r and omised to receive daily or stoss vitamin D therapy with follow-up at 4 - 6 months and 9 - 12 months . Biochemical and clinical parameters such as 25(OH)D , alkaline phosphatase , calcium and sun exposure were collected . RESULTS Seventy-three participants were enrolled ( 61 from a metropolitan and 12 from a rural area ) .  25(OH)D levels were greater than 78 nmol/L in 9/12 ( 75 % ) participants in the rural group and 21/61 ( 34 % ) in the metropolitan group . 25(OH)D levels were less than 78 nmol/L in 43/73 ( 59 % ) participants . Of these , 34/43 ( 79 % ) were insufficient ( 50 - 78 nmol/L ) , 8/43 ( 19 % ) mildly deficient ( 27.5 - 50 nmol/L ) and 1/43 ( 2 % ) deficient ( < 27.5 nmol/L ) . Daily vitamin D therapy had a higher average increase in 25(OH)D levels from baseline than stoss therapy ; however , this was not significant . CONCLUSION Vitamin D insufficiency is common in Aboriginal children of Western Australia and stoss therapy is a safe alternative to daily vitamin D therapy but requires further evaluation of timing and doses Background Vitamin D is a pleiotropic hormone important for the recovery of organ systems after critical illness . Recent observational studies have suggested that three out of every four children are vitamin D deficient following cardiac surgery , with inadequate preoperative intake and surgical losses playing important contributory roles . Observed associations between postoperative levels , cardiovascular dysfunction and clinical course suggest that perioperative optimization of vitamin D status could improve outcome . With this two-arm , parallel , double blind , r and omized controlled trial ( RCT ) , we aim to compare immediate postoperative vitamin D status in children requiring cardiopulmonary bypass for congenital heart disease who receive preoperative daily high dose vitamin D supplementation ( high-dose arm ) with those who receive  usual intake ( low-dose arm ) . Methods / Design Eligibility requirements include age ( > 36 weeks , < 18 years ) and a congenital heart defect requiring cardiopulmonary bypass surgical correction . Enrollment of 62 participants will take place at a single Canadian tertiary care center over a period of 2 years . Children r and omized to the high-dose group will receive age-based dosing that was informed by the Institute of Medicine ( IOM ) daily tolerable upper intake level ( < 1 year old = 1,600 IU/day , > 1 year old = 2,400 IU/day ) . Children in the low-dose arm will receive usual care based on IOM recommendations ( < 1 year old = 400 IU , > 1 year old = 600 IU ) . The primary outcome measure is immediate postoperative vitamin D status , using blood 25(OH)D. Discussion Maintaining adequate postoperative vitamin D levels following surgery could represent an effective therapy to speed recovery following CHD surgery . The proposed research project will determine whether preoperative supplementation with a dosing regimen based on the IOM recommended daily upper tolerable intake will prevent postoperative vitamin-D deficiency in the majority of children . The results will then be used to inform the design of a large international RCT exploring whether preoperative optimization of vitamin D status might improve short and long-term outcomes in this vulnerable population .Trial Registration Clinical trials.gov Identifier - NCT01838447 Date of registration : 11 April Vitamin D plays an important role in human health . Current recommendations for vitamin D intake and endogenous supply through sun exposure are not met in German pre-school children , and suboptimal serum 25-hydroxyvitamin D concentrations , especially during the winter months , are common . Consequently , vitamin D supplementation or fortification have gained increased acceptance . The KiMi trial ( Kindermilch = growing up milk ) was a prospect i ve , r and omized , and double-blind study in which young children ( 2–6 years of age , n = 92 ) were assigned to receive either vitamin D-fortified growing up milk ( 2.85 μg/100 ml ) or semi skimmed cow 's milk without added vitamin D. Daily consumption of fortified growing up milk contributed to the prevention of an otherwise frequently observed decrease in serum 25-hydroxyvitamin D concentration during winter ( before winter : median 21.5 ng/mL ( 10.1–43.0 ng/mL ) intervention vs. median 18.4 ng/mL ( 11.0–44.9 ng/mL ) control ; after winter : median 24.8 ng/mL ( 7.0–48.2 ng/mL ) intervention vs. median 13.6 ng/mL ( 7.0–36.8 ng/mL ) control ) and proved to be safe during summer ( median 27.6 ng/mL ( 18.8–40.5 ng/mL ) intervention vs. median 27.4 ng/mL ( 17.8–38.7 ng/mL ) control ) . Due to the high prevalence of vitamin D deficiency , fortification of growing up milk with vitamin D at a level used in this study could be an effective measure to improve vitamin D status Background Vitamin D insufficiency in children may have long-term skeletal consequences as vitamin D affects calcium absorption , bone mineralization and bone mass attainment . Methodology /Principal Findings This school-based study investigated vitamin D status and its association with vitamin D intake and bone health in 195 Finnish children and adolescents ( age range 7–19 years ) . Clinical characteristics , physical activity and dietary vitamin D intake were evaluated . Blood and urine sample s were collected for serum 25-hydroxyvitamin D ( 25-OHD ) and other parameters of calcium homeostasis . Bone mineral density ( BMD ) and body composition were measured with dual-energy X-ray absorptiometry ( DXA ) . Altogether 71 % of the subjects were vitamin D insufficient ( 25-OHD < 50 nmol/L ) . The median 25-OHD was 41 nmol/L for girls and 45 nmol/L for boys , and the respective median vitamin D intakes 9.1 µg/day and 10 µg/day . In regression analysis , after adjusting for relevant factors , 25-OHD concentration explained 5.6 % of the variance in lumbar BMD ; 25-OHD and exercise together explained 7.6 % of the variance in total hip BMD and 17 % of the variance in whole body BMD . S-25-OHD was an independent determinant of lumbar spine and whole body BMD and in magnitude surpassed the effects of physical activity . Conclusions / Significance Vitamin D insufficiency was common even when vitamin D intake exceeded the recommended daily intake . Vitamin D status was a key determinant of BMD . The findings suggest urgent need to increase vitamin D intake to optimize bone health in children The hypothesis that breastfed infants in Beijing , China , have low vitamin D status and that sunshine exposure increases serum 25-hydroxyvitamin D ( 25-OHD ) concentrations was tested in a r and omized prospect i ve study involving 42 healthy infants 1 - 8 months of age . 24 controls were exposed to the usual amount of sunshine , while the 18 cases were provided with 2 hours of sunshine/day . All infants were being breastfed without vitamin D supplementation .  Serum 25-OHD concentrations at entry into the study ranged from 3 - 61 ng/ml and increased with age . 3 infants in each group were diagnosed as having rickets . Serum 25-OHD concentrations did not change significantly during the 2-month study period among controls , while serum 25-OHD values increased significantly in the experimental group . Final infant serum 25-OHD concentrations correlated with ultraviolet exposure scores ( p.001 ) . The estimate of ultraviolet score needed to maintain a serum 25-OHD of 11 ng/ml was 2.4 ( 24 minutes/day with only the face uncovered ) . Rickets has been reported in as many as 18 % of Chinese infants and seems to especially affect those 2 - 4 months of age . The fact that not all infants with rickets in this study had low 25-OHD concentrations suggests 2 possibilities : 1 ) not all rickets is necessarily related to a vitamin D deficiency , or 2 ) serum 25-OHD concentrations are not the best indicator of vitamin D status . The low serum 25-OHD concentrations in many Chinese infants may be related to low maternal milk vitamin D content result ing from the lack of vitamin D food fortification . Overall , these results suggest that the diet of breastfed Chinese infants should be supplemented with orally administered vitamin This study deals with the relationship between the occurrence of hypercalcemia and the administration of prophylactic doses of vitamin D in children with hypothyroidism , before and during L-thyroxine ( LT4 ) treatment .  The goal of the study was to determine the dosage of vitamin D necessary to prevent rickets without inducing hypercalcemia . There was a 23 % prevalence of hypercalcemia at the time of the diagnosis of hypothyroidism by screening whereas it was 21 % in the children who were not given vitamin D  during the first 3 months of LT4 treatment . This figure was significantly higher in those who were given vitamin D during the first 3 months of treatment and reached 70 % . However , one of the 19 children not given vitamin D presented with biological signs evoking vitamin D deficiency . In conclusion , in hypothyroid infants , vitamin D should be administered carefully during the first 6 months of treatment and restricted to children at risk for developing vitamin D deficiency
Whether or not outcomes such as osteoporosis ( or low bone mass ) and specific types of cancer may be prevented by ' generous ' vitamin D supplementation is unclear and mostly based on indirect epidemiologic data not clearly substantiated by r and omized controlled trials SUMMARY The dose of daily vitamin D supplements needed to prevent rickets is probably much lower than that recommended by most expert committees .
PURPOSE OF REVIEW To underst and the basis for current recommendations for  vitamin D supplementation in childhood and the differences between the recommendations published by major expert committees , using the Medline engine of the US National Library of Medicine and the National Institutes of Health .
Most trials have examined the question of whether a specific daily vitamin D dose is capable or not to prevent rickets ( by study ing surrogate markers of rickets ) .