Vitamin D concentrations in Asian children aged 2 years living in England: population survey

Global Health Disparities in Childhood Rickets

Nutritional rickets is a global health problem reflecting both historical and contemporary health disparities arising from racial, ethnic, environmental, and geopolitical circumstances. It primarily affects marginalized populations and can contribute to long-term morbidity. Deficits in bone health in childhood may also contribute to osteomalacia/osteoporosis. Solutions require a global public health approach.

Vitamin D in pediatric age: Current evidence, recommendations, and misunderstandings

In recent years vitamin D has been in the spotlight of many researchers for its possible role in various disorders, including autoimmune and infectious diseases. Even if vitamin D deficiency remains a major public health problem, its symptomatic manifestations are less and less common in clinical practice, and pediatric age represents a “gray area” where vitamin D supplementation is often administered in the absence of an effective evaluation of its status. Moreover, a poor knowledge about different definitions of “deficiency,” “insufficiency,” and similar terms is spread among clinicians, while guidelines are not univocal, especially after the first year of life. The aim of this brief opinion paper is to sum up recent evidence about vitamin D status and its supplementation in pediatrics, in order to better clarify a common definition of its deficiency. The aim of this opinion article is to raise awareness on this topic among clinicians and encourage a discussion on the real need for routine 25-hydroxycholecalciferol serum evaluation and its supplementation.

Changes in Bone Turnover, Inflammatory, Oxidative Stress, and Metabolic Markers in Women Consuming Iron plus Vitamin D Supplements: a Randomized Clinical Trial

We aimed to investigate whether combination of vitamin D and iron supplementation, comparing vitamin D alone, could modify bone turnover, inflammatory, oxidative stress, and metabolic markers. Eighty-seven women with hemoglobin (Hb) ≤ 12.7 g/dL and 25OHD ≤ 29 ng/mL vitamin D deficiency/insufficiency aged 18-45 years were randomly assigned into two groups: (1) receiving either 1000 IU/day vitamin D3 plus 27 mg/day iron (D-Fe); (2) vitamin D3 plus placebo supplements (D-P), for 12 weeks. In D-Fe group, significant decrease in red blood cells (RBC) (P = 0.001) and hematocrit (Hct) (P = 0.004) and increases in mean corpuscular hemoglobin concentration (MCHC) (P = 0.001), 25OHD (P < 0.001), osteocalcin (P < 0.001), high-density cholesterol (HDL) (P = 0.041), and fasting blood sugar (FBS) (P < 0.001) were observed. D-P group showed significant decrease in RBC (P < 0.001), Hb (P < 0.001), Hct (P < 0.001), mean corpuscular volume (MCV) (P = 0.004), mean corpuscular hemoglobin (MCH) (P < 0.001), MCHC (P = 0.005), serum ferritin (P < 0.001), and low-density cholesterol (LDL) (P = 0.016) and increases of 25OHD (P < 0.001), osteocalcin (P < 0.001), C-terminal telopeptide (CTX) (P = 0.025), triglyceride (TG) (P = 0.004), FBS (P < 0.001), and interleukin-6 (IL-6) (P = 0.001) at week 12. After the intervention, the D-P group had between-group increases in mean change in the osteocalcin (P = 0.007) and IL-6 (P = 0.033), and decreases in the RBC (P < 0.001), Hb (P < 0.001), Hct (P < 0.001), and MCV (P = 0.001), compared with the D-Fe group. There were significant between-group changes in MCH (P < 0.001), MCHC (P < 0.001), ferritin (P < 0.001), and serum iron (P = 0.018). Iron-vitamin D co-supplementation does not yield added benefits for improvement of bone turnover, inflammatory, oxidative stress, and metabolic markers, whereas, vitamin D alone may have some detrimental effects on inflammatory and metabolic markers. IRCT registration number: IRCT201409082365N9.

Influence of maternal use of tenofovir disoproxil fumarate or zidovudine in Vietnamese pregnant women with HIV on infant growth, renal function, and bone health

Tenofovir disoproxil fumarate (TDF) is still widely prescribed for human immunodeficiency virus (HIV)-infected pregnant women, despite its renal and bone toxicity. Although TDF-exposed infants often show transient growth impairment, it is not clear whether maternal TDF causes infantile rickets via maternal/fetal renal dysfunction in Asian populations. This prospective observational study was conducted in Vietnam and involved pregnant HIV-infected women treated with TDF-based regimen (TDF group) or zidovudine-based regimen (AZT-group). At birth, 3, 12, and 18 months of age, and included body length, weight, head circumference, serum alkaline phosphatase (ALP), creatinine, calcium, phosphorus, urine-β2-microglobulin (U-BMG), percentage of tubular reabsorption of phosphate (%TRP), and radiographic wrist score for rickets. Age-adjusted multivariate linear regression analysis evaluated the association of TDF/AZT use during pregnancy with fetal renal function and bone health. The study included 63 mother-infant pairs (TDF group = 53, AZT group = 10). In the mothers, detectable U-BMG (>252 μg/L) was observed more frequently in the TDF- than AZT group (89 vs 50%, p<0.001), but other renal/bone parameters were similar. In infants, maternal TDF use was not associated with growth impairment, renal dysfunction, or abnormal bone findings, but with a slightly higher ALP levels (p = 0.019). However, shorter length was associated with maternal AZT (p = 0.021), and worse radiographic scores were associated with LPV/r (p = 0.024). In Vietnamese population, TDF usage during pregnancy was not associated with infant transient rickets, growth impairment, or renal dysfunction, despite mild maternal tubular impairment. Maternal AZT and LPV/r influenced infant growth and bone health, though further studies are needed to confirm this finding.

Very high prevalence of 25-hydroxyvitamin D deficiency in 6433 UK South Asian adults: analysis of the UK Biobank Cohort

Little research has assessed serum 25-hydroxyvitamin D (25(OH)D) concentration and its predictors in Western-dwelling South Asians in a relatively large sample size. This observational, cross-sectional analysis assessed baseline prevalence of 25(OH)D deficiency in UK-dwelling South Asians (aged 40-69 years, 2006-2010) from the UK Biobank Cohort. Serum 25(OH)D measurements were undertaken using the DiaSorin Liaison XL assay. Of 6433 South Asians with a 25(OH)D measurement, using commonly used cut-off thresholds, 55 % (n 3538) had 25(OH)D < 25 nmol/l (severe deficiency) and 92 % (n 5918) had 25(OH)D < 50 nmol/l (insufficiency). Of the participants with a measurement, 20 % (n 1287) had 25(OH)D concentration <15 nmol/l (very severe deficiency). When 824 participants with undetectable (<10 nmol/l) 25(OH)D measurements were included (total n 7257), 29 % (n 2105) had 25(OH)D < 15 nmol/l, 60 % (n 4354) had 25(OH)D < 25 nmol/l and 93 % (n 6749) had 25(OH)D < 50 nmol/l. Logistic regression predictors of 25(OH)D < 25 nmol/l included the following characteristics: being male; Pakistani; higher BMI; 40-59 years old; never consuming oily fish; summer sun exposure <5 h/d, not using a vitamin D-containing supplement, measurement in winter or spring and vegetarianism. In terms of region, median 25(OH)D concentration was 19-20 nmol/l in Scotland, Northern England, the Midlands and Wales. Across Southern England and London, it was slightly higher at 24-25 nmol/l. Our analyses suggest the need for increased awareness of vitamin D deficiency in South Asians as well as urgent public health interventions to prevent and treat vitamin D deficiency in this group.

A High Prevalence of Vitamin D Deficiency Observed in an Irish South East Asian Population: A Cross-Sectional Observation Study

At northern latitudes, non-ethnic population groups can be at an increased risk of vitamin D deficiency (defined as a 25-hydroxyvitamin D [25(OH)D] status ≤30 nmol/L). The vitamin D status of ethnic minority groups has been examined both in UK and European populations, but not in the Irish context. The aim of this study is to assess the vitamin D status from a selection of the Dublin population of South East Asian descent. A search was conducted, using the laboratory information system of St James's Hospital, Dublin, for vitamin D requests by General practitioners. From 2013 to 2016, 186 participants were identified and 25(OH)D analysis was quantified using liquid chromatography-tandem mass spectrometry (LC-MS-MS). Overall, the median age was 32 years, 51% were male, and the 25(OH)D concentration ranged from 10 to 154 nmol/L. In total, 66.7% of the total sample were vitamin D deficient and 6.7% had a 25(OH)D status greater than 50 nmol/L (the 25(OH)D concentration defined by the EU as 'sufficient'). Females had a significantly higher 25(OH)D concentration than males (25.0 vs. 18.0 nmol/L; p = 0.001) but both groups had a significant proportion with deficient status (56% and 76.8%, respectively). Seasonal variation of 25(OH)D was not evident while high rates of deficiency were also observed in those aged <18 years and >50 years. Given the importance of vitamin D for health, this sub-population could be at a significantly increased risk of rickets, impaired bone metabolism, and osteoporosis. In addition, vitamin D deficiency has been associated with several non-bone related conditions, including cardiovascular disease and diabetes. Currently, there is no unique vitamin D intake or vitamin D status maintenance guidelines recommended for adults of non-Irish descent; this needs to be considered by the relevant public health bodies in Ireland.

Vitamin D deficiency in western dwelling South Asian populations: an unrecognised epidemic

Vitamin D deficiency (25-hydroxyvitamin D; 25(OH)D) is at epidemic proportions in western dwelling South Asian populations, including severe deficiency (<12⋅5 nmol/l) in 27-60% of individuals, depending on season. The paper aimed to review the literature concerning vitamin D concentrations in this population group. Research from the UK and Europe suggests a high prevalence of South Asians with 25(OH)D concentration <25 nmol/l, with most having a 25(OH)D concentration of <50 nmol/l. In Canada, South Asians appear to have a slightly higher 25(OH)D concentration. There are few studies from the United States, South Africa and Australasia. Reasons for vitamin D deficiency include low vitamin D intake, relatively high adiposity, sun exposure avoidance and wearing of a covered dress style for cultural reasons. Possible health effects of deficiency include bone diseases such as rickets and hypocalcaemia in children and osteomalacia in adults. Vitamin D deficiency may also increase the risk of other chronic diseases. Increased fortification of food items relevant to South Asian groups (e.g. chapatti flour), as well as increased use of vitamin D supplements may help reduce this epidemic. Introducing culturally acceptable ways of increasing skin exposure to the sun in South Asian women may also be beneficial but further research is needed to assess the effectiveness of different approaches. There may be a need for a South Asian specific vitamin D dietary intake guideline in western countries. To conclude, vitamin D deficiency is epidemic in South Asians living in western countries and there is a clear need for urgent public health action.

Epidemiology and risk factors of hypovitaminosis D in a cohort of internationally adopted children: a retrospective study

Background

Predictors of hypovitaminosis D were extensively studied in the adult population, leading to an approximately complete understanding of them, while there is a lack of studies in the pediatric population, especially in migrant and internationally adopted children.

In this retrospective study, we tried to identify the major laboratory predictors of hypovitaminosis D in a cohort of internationally adopted children.

Methods

Data were extracted from the database of the “Ethnopediatrics Outpatient Clinic” of the “A. Gemelli” Foundation University Hospital in Rome, Italy. Our study included 873 children evaluated from March 2007 to May 2016. Analysis of variance, chi square test, t test and multivariate logistic regression were performed, a “p” value < 0.05 was considered significant, with a confidence interval of 95%.

Results

We did not find any significant correlation between Vitamin D and Calcium, Phosphates or Magnesium levels within the population we examined. Moreover, parathyroid hormone is not a good predictor of Vitamin D Status.

Conclusions

Considering the strong influence Vitamin D status has not only on bone health, but also on general well-being, it is due to perform a vitamin D assessment as soon as possible, especially in internationally adopted children.

Electronic supplementary material

The online version of this article (10.1186/s13052-018-0527-4) contains supplementary material, which is available to authorized users.

Vitamin D deficiency in immigrants

Vitamin D deficiency and rickets are more common in non-western immigrants and refugees than in the native population. Severe vitamin D deficiency (serum 25-hydroxyvitamin D <25 nmol/l) may occur in up to 50% of children and adults of non-western origin. They are not used to sunshine exposure due to the often excessive sunshine in the country of origin. They usually have a more pigmented skin. Non-western immigrants and refugees often wear skin-covering clothes due to religious or cultural tradition. The food contains little vitamin D with the exception of fatty fish. In addition, many immigrants have a low calcium intake. Complaints may include fatigue, pain in shoulders, ribs, lower back and thighs. Neonates and young children may have spasms and convulsions due to hypocalcemia. Older children and adolescents may have bone pain, muscle weakness and skeletal deformities. Widening of the wrist, chest deformities and bowing of the legs may occur, and longitudinal growth is delayed. In adults, muscle weakness and bone pain are predominant. Laboratory examination may show hypocalcemia and hypophosphatemia and elevated alkaline phosphatase. The serum 25(OH)D is below 25 nmol/l in case of severe vitamin D deficiency with symptoms. Impaired 25-hydroxylation or 1α-hydroxylation may occur in case of severe liver or renal disease or by genetic causes. Radiographs of wrists or knees may show widening of the growth plates and cupping of radius and ulna may confirm the diagnosis. In adolescents and adults, radiographs of painful bones may show pseudofractures or Looser zones. Rickets and osteomalacia are treated by vitamin D3 2000 IU/d in infants, 3000-6000 IU/d in older children in combination with calcium 500 mg /d. In osteomalacia, the adult vitamin D3 dose is 2000-3000 IU/d, combined with calcium 1000-2000 mg/d. Prevention of vitamin D deficiency can be done with vitamin D3 400-800 IU/d, depending on age. Nutritional measures include fortification of milk or other foods.

Serum vitamin D profile of Nigerian children with asthma: Association with asthma severity and control

OBJECTIVE

Childhood asthma is a chronic inflammatory airway disorder with increasing prevalence even in Africa. Vitamin D, with anti-inflammatory and immune-modulatory properties, may have effects on the severity and level of symptoms control in childhood asthma. We aimed to assess the serum vitamin D levels in children with asthma as related to disease severity and control in a tropical region.

METHODS

A hospital based comparative cross sectional study was conducted in western Nigeria. Serum vitamin D (25-OH-D) levels of all the children, assayed using high-performance liquid chromatography (HPLC), were compared to the various disease severity and levels of asthma control as well as between the asthmatic and non-asthmatic children.

RESULTS

A total of 206 children (103 asthmatics and 103 non-asthmatics) were recruited with a mean (SD) age of 6.6 (3.7) years. The majority (82.5%) of the children with asthma had mild intermittent form, 63.1% had well controlled symptoms while 33.0% and 3.9% had partly controlled and uncontrolled symptoms, respectively. None of the children were deficient in vitamin D. The mean (SD) serum vitamin D levels of the children with asthma (49.2 [7.2] ng/mL) was significantly lower than those without asthma (51.2 [6.9] ng/mL, P = 0.043). Varying degrees of asthma severity and levels of symptoms control were not affected by serum vitamin D levels.

CONCLUSION

Children with asthma in Nigeria had marginally but significantly lower mean serum vitamin D levels when compared with their counterparts without asthma. However, serum vitamin D level does not seem to be associated with childhood asthma severity and control in these children with normal serum vitamin D levels.

Vitamin D and mental health in children and adolescents

While vitamin D is known to be relevant for bone health, evidence has recently accumulated for an impact on mental health. To identify the potential benefits and limitations of vitamin D for mental health, an understanding of the physiology of vitamin D, the cut-off values for vitamin D deficiency and the current status of therapeutic trials is paramount. Results of a systematic PUBMED search highlight the association of vitamin D levels and mental health conditions. Here, we focus on children and adolescents studies as well as randomized controlled trials on depression in adults. 41 child and adolescent studies were identified including only 1 randomized controlled and 7 non-controlled supplementation trials. Overall, results from 25 cross-sectional studies as well as from 8 longitudinal studies suggest a role of vitamin D in the pathogenesis of mental disorders in childhood and adolescence. Findings from supplementation trials seem to support this hypothesis. However, randomized controlled trials in adults revealed conflicting results. Randomized controlled trials in childhood and adolescents are urgently needed to support the potential of vitamin D as a complementary therapeutic option in mental disorders. Study designs should consider methodological challenges, e.g., hypovitaminosis D at baseline, appropriate supplementation doses, sufficient intervention periods, an adequate power, clinically validated diagnostic instruments, and homogenous, well-defined risk groups.

Vitamin D supplementation for preventing infections in children under five years of age

BACKGROUND

Vitamin D is a micronutrient important for bone growth and immune function. Deficiency can lead to rickets and has been linked to various infections, including respiratory infections. The evidence on the effects of supplementation on infections in children has not been assessed systematically.

OBJECTIVES

To evaluate the role of vitamin D supplementation in preventing pneumonia, tuberculosis (TB), diarrhoea, and malaria in children under five years of age. This includes high-, middle-, and low-income countries.

SEARCH METHODS

We searched the Cochrane Infectious Diseases Group Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane Library, MEDLINE, EMBASE, LILACS, the WHO International Clinical Trials Registry Platform (ICTRP; http://www.who.int/ictrp/en/) , ClinicalTrials.gov and the ISRCTN registry (http://www.isrctn.com/) up to 16 June 2016.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that evaluated preventive supplementation of vitamin D (versus placebo or no intervention) in children under five years of age.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the titles and abstracts, extracted the data, and assessed the risk of bias of included trials.

MAIN RESULTS

Four trials met the inclusion criteria, with a total of 3198 children under five years of age, and were conducted in Afghanistan, Spain, and the USA. Prevalence of vitamin D deficiency varied widely in these populations (range: 73.1% in Afghanistan, 10 to 12% in USA, and 6.2% in Spain). The included trials evaluated mortality (two trials), pneumonia incidence (two trials), diarrhoea incidence (two trials), hospitalization (two trials), and mean serum vitamin D concentrations (four trials).We do not know whether vitamin D supplementation impacts on all-cause mortality because this outcome was underpowered due to few events (risk ratio (RR) 1.43, 95% confidence interval (CI) 0.54 to 3.74; one trial, 3046 participants, low quality evidence).For pneumonia, episodes of 'radiologically confirmed' first or only episode of pneumonia were little different in the supplemented and unsupplemented group (Rate Ratio: 1.06, 95% confidence interval (CI) 0.89 to 1.26; two trials, 3134 participants, moderate quality evidence), and similarly for children with confirmed or unconfirmed pneumonia (RR 0.95, 95% CI 0.87 to 1.04; one trial, 3046 participants). In these two trials there were no obvious differences between supplemented and unsupplemented children regarding episodes of diarrhoea.In the single large trial from Afghanistan, the trial authors reported that vitamin D supplementation was associated with an increase in repeat episodes of pneumonia confirmed by chest radiograph (RR 1.69, 95% CI 1.28 to 2.21; one trial, 3046 participants), but not reflected in the outcome of confirmed or unconfirmed pneumonia (RR 1.06, 95% CI 1.00 to 1.13; one trial, 3046 participants).For hospital admission measured in one small trial, there was no difference detected (RR 0.86, 95% CI 0.20 to 3.62; one trial, 88 participants; very low quality evidence).The mean serum vitamin D concentrations were higher in supplemented compared to unsupplemented children at the end of supplementation (MD 7.72 ng/mL, 95% CI 0.50 to 14.93; four trials, 266 participants, low quality evidence). These results were driven primarily by two smaller trials with large magnitudes of effect. In the other two bigger trials, serum vitamin D concentrations were elevated in the intervention group for most of the trial duration but not at the end of supplementation. This may be due to time elapsed at measurement from the last dose, incomplete compliance, or increased need of vitamin D with infant age.We did not find any trial that reported on the incidence of TB, malaria or febrile illness, duration of pneumonia, duration of diarrhoea, severity of infection, and cause-specific mortality (due to TB, diarrhoea, or malaria).

AUTHORS' CONCLUSIONS

Evidence from one large trial did not demonstrate benefit of vitamin D supplementation on the incidence of pneumonia or diarrhoea in children under five years. To our knowledge, trials that evaluated supplementation for preventing other infections, including TB and malaria, have not been performed.

Independent association of circulating vitamin D metabolites with anemia risk in patients scheduled for cardiac surgery

BACKGROUND

Preoperative anemia is considered an independent risk factor of poor clinical outcome in cardiac surgical patients. Low vitamin D status may increase anemia risk.

METHODS

We investigated 3,615 consecutive patients scheduled for cardiac surgery to determine the association between preoperative anemia (hemoglobin [Hb] <12.5 g/dL) and circulating levels of the vitamin D metabolites 25-hydroxyvitamin D (25OHD) and 1,25-dihydroxyvitamin D (1,25[OH]2D).

RESULTS

Of the study cohort, 27.8 % met the criteria for anemia. In patients with deficient 25OHD levels (<30 nmol/l) mean Hb concentrations were 0.5 g/dL lower than in patients with adequate 25OHD levels (50.0-125 nmol/l; P<0.001). Regarding 1,25(OH)2D, mean Hb concentrations were 1.2 g/dL lower in the lowest 1,25(OH)2D category (<40 pmol/l) than in the highest 1,25(OH)2D category (>70 pmol/l; P<0.001). In multivariable-adjusted logistic regression analyses, the odds ratios for anemia of the lowest categories of 25OHD and 1,25(OH)2D were 1.48 (95%CI:1.19-1.83) and 2.35 (95%CI:1.86-2.97), compared with patients who had adequate 25OHD levels and 1,25(OH)2D values in the highest category, respectively. Anemia risk was greatest in patients with dual deficiency of 25OHD and 1,25(OH)2D (multivariable-adjusted OR = 3.60 (95%CI:2.40-5.40). Prevalence of deficient 25OHD levels was highest in anemia of nutrient deficiency, whereas low 1,25(OH)2D levels were most frequent in anemia of chronic kidney disease.

CONCLUSION

This cross-sectional study demonstrates an independent inverse association between vitamin D status and anemia risk. If confirmed in clinical trials, preoperative administration of vitamin D or activated vitamin D (in case of chronic kidney disease) would be a promising strategy to prevent anemia in patients scheduled for cardiac surgery.

Vitamin D Status Affects Serum Metabolomic Profiles in Pregnant Adolescents

Vitamin D is linked to a number of adverse pregnancy outcomes through largely unknown mechanisms. This study was conducted to examine the role of vitamin D status in metabolomic profiles in a group of 30 pregnant, African American adolescents (17.1 ± 1.1 years) at midgestation (26.8 ± 2.8 weeks), in 15 adolescents with 25-hydroxy vitamin D (25(OH)D) ≥20 ng/mL, and in 15 teens with 25(OH)D <20 ng/mL. Serum metabolomic profiles were examined using gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry. A novel hierarchical mixture model was used to evaluate differences in metabolite profiles between low and high groups. A total of 326 compounds were identified and included in subsequent statistical analyses. Eleven metabolites had significantly different means between the 2 vitamin D groups, after correcting for multiple hypothesis testing: pyridoxate, bilirubin, xylose, and cholate were higher, and leukotrienes, 1,2-propanediol, azelate, undecanedioate, sebacate, inflammation associated complement component 3 peptide (HWESASXX), and piperine were lower in serum from adolescents with 25(OH)D ≥20 ng/mL. Lower maternal vitamin D status at midgestation impacted serum metabolic profiles in pregnant adolescents.

Vitamin D deficiency in cord plasma from multiethnic subjects living in the tropics

BACKGROUND

Vitamin D deficiency is commonly reported in high-latitude areas and in dark-pigmented individuals. However, nothing is known about vitamin D in cord blood from multiethnic subjects living in the tropics.

OBJECTIVE

Our study objective was to determine the prevalence of vitamin D deficiency in summer and winter in cord blood from multiethnic individuals in Hawai'i where sufficient sun irradiance occurs year-round for cutaneous vitamin D production.

METHODS

25-Hydroxyvitamin D (25(OH)D) levels were quantified by enzyme immunoassay in 100 cord plasma samples from apparently healthy full-term newborns and their mothers. Stratification was performed by birth season and ethnicity.

RESULTS

Mean 25(OH)D levels were 24.5 ng/mL (9.1-68.3 ng/mL). Overall, 28% of samples were vitamin D deficient (<20 ng/mL) and 50% were insufficient (20-30 ng/mL). 25(OH)D levels (ng/mL) were highest in Caucasians (30.5, n = 19), followed by Asians (25.1, n = 43), Hispanics (21.5, n = 3), Pacific Islanders (20.0, n = 25), and African Americans (19.6, n = 2). Differences among groups were significant (p = 0.008). Cord plasmas from summer versus winter were higher overall (p = 0.001) and among Asians (p = 0.0003). Seasonal changes were correlated with sun irradiance overall (r = 0.43, p = 0.0001), among Caucasians (r = 0.45, p = 0.05), and among Asians (r = 0.45, p = 0.0001).

CONCLUSION

Our results suggest that prenatal supplement recommendations of 400 IU vitamin D/day do not protect against vitamin D deficiency, even in subjects living in the tropics where ample sun irradiance exists for cutaneous vitamin D synthesis. The high prevalence of vitamin D deficiency we observed emphasizes the necessity for regular 25(OH)D monitoring, particularly during pregnancy and lactation, in dark-pigmented individuals, and during winter months.

Vitamin D in the healthy European paediatric population

In recent years, reports suggesting a resurgence of vitamin D deficiency in the Western world, combined with various proposed health benefits for vitamin D supplementation, have resulted in increased interest from health care professionals, the media, and the public. The aim of this position paper is to summarise the published data on vitamin D intake and prevalence of vitamin D deficiency in the healthy European paediatric population, to discuss the health benefits of vitamin D and to provide recommendations for the prevention of vitamin D deficiency in this population. Vitamin D plays a key role in calcium and phosphate metabolism and is essential for bone health. There is insufficient evidence from interventional studies to support vitamin D supplementation for other health benefits in infants, children, and adolescents. The pragmatic use of a serum concentration >50 nmol/L to indicate sufficiency and a serum concentration <25 nmol/L to indicate severe deficiency is recommended. Vitamin D deficiency occurs commonly among healthy European infants, children, and adolescents, especially in certain risk groups, including breast-fed infants, not adhering to the present recommendation for vitamin D supplementation, children and adolescents with dark skin living in northern countries, children and adolescents without adequate sun exposure, and obese children. Infants should receive an oral supplementation of 400 IU/day of vitamin D. The implementation should be promoted and supervised by paediatricians and other health care professionals. Healthy children and adolescents should be encouraged to follow a healthy lifestyle associated with a normal body mass index, including a varied diet with vitamin D-containing foods (fish, eggs, dairy products) and adequate outdoor activities with associated sun exposure. For children in risk groups identified above, an oral supplementation of vitamin D must be considered beyond 1 year of age. National authorities should adopt policies aimed at improving vitamin D status using measures such as dietary recommendations, food fortification, vitamin D supplementation, and judicious sun exposure, depending on local circumstances.

Seizures as initial manifestation of vitamin D-deficiency rickets in a 5-month-old exclusively breastfed infant

Despite the fact that sunlight-dependent skin synthesis is the major mechanism for vitamin D synthesis in vivo, vitamin D-deficiency rickets continues to occur in exclusively breastfed infants in Greece. We present such a case in a 5-month-old infant who presented with afebrile seizures and whose mother was underexposed to sunlight due to veiling for religious reasons. Additionally, we briefly but thoroughly review the relevant medical literature. A high index of suspicion is required for nutritional rickets, when seizures occur in exclusively breastfed infants whose mothers have inadequate exposure to sunlight.

Predictors of anaemia and iron deficiency in HIV-infected pregnant women in Tanzania: a potential role for vitamin D and parasitic infections

OBJECTIVE

Anaemia is common during pregnancy, and prenatal Fe supplementation is the standard of care. However, the persistence of anaemia despite Fe supplementation, particularly in HIV infection, suggests that its aetiology may be more complex and warrants further investigation. The present study was conducted to examine predictors of incident haematological outcomes in HIV-infected pregnant women in Tanzania.

DESIGN

Prospective cohort study. Cox proportional hazards and binomial regression models were used to identify predictors of incident haematological outcomes: anaemia (Hb < 110 g/l), severe anaemia (Hb < 85 g/l) and hypochromic microcytosis, during the follow-up period.

SETTING

Antenatal clinics in Dar es Salaam, Tanzania.

SUBJECTS

Participants were 904 HIV-infected pregnant women enrolled in a randomized trial of vitamins (1995-1997).

RESULTS

Malaria, pathogenic protozoan and hookworm infections at baseline were associated with a two-fold increase in the risk of anaemia and hypochromic microcytosis during follow-up. Higher baseline erythrocyte sedimentation rate and CD8 T-cell concentrations, and lower Hb concentrations and CD4 T-cell counts, were independent predictors of incident anaemia and Fe deficiency. Low baseline vitamin D (<32 ng/ml) concentrations predicted a 1.4 and 2.3 times greater risk of severe anaemia and hypochromic microcytosis, respectively, during the follow-up period.

CONCLUSIONS

Parasitic infections, vitamin D insufficiency, low CD4 T-cell count and high erythrocyte sedimentation rate were the main predictors of anaemia and Fe deficiency in pregnancy and the postpartum period in this population. A comprehensive approach to prevent and manage anaemia, including micronutrient supplementation and infectious disease control, is warranted in HIV-infected women in resource-limited settings - particularly during the pre- and postpartum periods.

Hb level in relation to vitamin D status in healthy infants and toddlers

Objective

To assess the presence of an association between vitamin D deficiency and anaemia in Jordanian infants and toddlers, in whom both vitamin D deficiency and anaemia have previously been proved to be common separately.

Design

Cross-sectional prospective study.

Setting

Department of Paediatrics, Princess Rahma Teaching Hospital, Jordan.

Subjects

Healthy infants and children aged 6–36 months who were seen for primary care.

Results

Out of 203 infants and toddlers included in the study, the anaemia prevalence was 40·4 %. The prevalence of anaemia among infants (n 110) was 51·8 %, whereas it was 26·9 % among toddlers (n 93). No association between vitamin D status and anaemia was found.

Conclusions

Vitamin D deficiency is not a risk for anaemia in infants and toddlers.

Maternal vitamin D status and child morbidity, anemia, and growth in human immunodeficiency virus-exposed children in Tanzania

BACKGROUND

Vitamin D may help prevent adverse pediatric outcomes, including infectious diseases and growth failure, based on its role in immune and metabolic functions. We examined the association of maternal vitamin D status and pediatric health outcomes in children born to human immunodeficiency virus (HIV)-infected women.

METHODS

Vitamin D status was determined in 884 HIV-infected pregnant women at 12 to 27 weeks of gestation in a trial of vitamin supplementation (not excluding vitamin D) in Tanzania. Information on child morbidities, anemia and hypochromic microcytosis, and anthropometry was recorded through monthly clinic visits. Generalized estimating equations and Cox proportional hazards models were used to assess the relationships of outcomes with maternal vitamin D status.

RESULTS

A total of 39% of women had low vitamin D levels (<32 ng/mL). Children born to women with low vitamin D status were 1.11 times more likely to report cough during follow-up (relative risk [RR], 1.11; 95% confidence interval [CI], 1.02-1.21). No significant associations were noted for other respiratory symptoms, diarrhea, or anemia outcomes. Low maternal vitamin D status was associated with significantly increased risk of stunting (height-for-age z score, <-2; RR, 1.29; 95% CI, 1.05-1.59) and being underweight (weight-for-age z score, <-2; RR, 1.33; 95% CI, 1.03-1.71).

CONCLUSIONS

Maternal vitamin D status may be important for preventing respiratory infections and ensuring optimal growth in HIV-exposed children.

Vitamin D status in paediatric patients with cancer

BACKGROUND

Children with malignant disease are at increased risk of bone disorders and cardiovascular disease. Vitamin D status may influence this risk and so we assessed vitamin D levels in children with malignant disease undergoing active treatment or surveillance post-therapy.

PROCEDURE

This was an outpatient-based cross-sectional study of 61 children with a history of malignancy (median age 11.1 years; range 1.5-24.4 years) and 60 control subjects (median age 8.4 years; range 0.2-18.0 years) attending hospital for the management of non-malignant disorders. Serum vitamin D (25-OH-D), parathormone levels and bone biochemistry were determined. Vitamin D status and its relationship to age, sex, ethnicity, time of sampling and presence of malignant disease was determined.

RESULTS

Vitamin D status was suboptimal in 62% of cases (25-OH-D < 50 nmol/L [20 ng/ml]). Vitamin D deficiency (25-OH-D < 25 nmol/L [10 ng/ml]) was more common in children with malignant disease than controls (21.3% vs. 3.3%; P = 0.013). Month of sampling (P < 0.001), ethnicity (P < 0.001), older age (P = 0.011), and history of malignancy (P = 0.012) were associated with a poorer vitamin D status.

CONCLUSIONS

Vitamin D levels [25-OH-D] are lower in survivors of childhood cancer in comparison to control children with the majority either insufficient or deficient. Assessment and adequate replacement of vitamin D status may be of particular value in this group of children.

Vitamin D deficiency is an independent predictor of anemia in end-stage heart failure

Both, anemia and vitamin D deficiency are prevalent in patients with heart failure. According to recent evidence, vitamin D may stimulate erythropoiesis. We measured circulating 25-hydroxyvitamin D (25[OH]D), 1,25-dihydroxyvitamin D (1,25[OH](2)D) and hemoglobin (Hb) in a cross-sectional study in 364 end-stage heart failure patients awaiting cardiac transplantation, of whom 52.6% met the criteria for anemia (Hb < 13 g/dl in males and <12 g/dl in females). None of the patients were on erythrocyte-stimulating agents. Of the study cohort, 87.8% had 25(OH)D concentrations below 50 nmol/l. The mean Hb concentrations were significantly reduced in the lower tertiles of 25(OH)D and 1,25(OH)(2)D (P < 0.001). In multivariate-adjusted logistic regression analyses, the odds ratios for anemia of the lowest tertile of 25(OH)D (<18 nmol/l) and 1,25(OH)(2)D (<40 pmol/l) were 2.69 (1.46-5.00) and 4.08 (2.18-7.62) compared with their respective highest tertile (>32 nmol/l and >70 pmol/l). Patients with severe dual deficiency of 25(OH)D and 1,25(OH)(2)D had an odds ratio for anemia of 9.87 (95% CI 3.59-27.1) compared with patients in the highest tertile for both vitamin D metabolites. Circulating 1,25(OH)(2)D was directly related to circulating 25(OH)D levels and kidney function (P < 0.001), and inversely associated with C-reactive protein (P = 0.020). Our data demonstrate that vitamin D deficiency is independently associated with low Hb values and anemia in end-stage heart failure. Circulating 1,25(OH)(2)D is a better predictor of anemia than circulating 25(OH)D. Prospective randomized studies with administration of vitamin D (metabolites) will have to clarify if the association of vitamin D deficiency with anemia is causal.

Prevalence of vitamin D deficiency among Turkish, Moroccan, Indian and sub-Sahara African populations in Europe and their countries of origin: an overview

Vitamin D status of nonwestern immigrants in Europe was poor. Vitamin D status of nonwestern populations in their countries of origin varied, being either similar to the immigrant populations in Europe or higher than in European indigenous populations. Vitamin D concentrations in nonwestern immigrant populations should be improved.

PURPOSE

The higher the latitude, the less vitamin D is produced in the skin. Most European countries are located at higher latitudes than the countries of origin of their nonwestern immigrants. Our aim was to compare the serum 25-hydroxyvitamin D (25(OH)D) concentration of nonwestern immigrant populations with those of the population in their country of origin, and the indigenous population of the country they migrated to.

METHODS

We performed literature searches in the "PubMed" and "Embase" databases, restricted to 1990 and later. The search profile consisted of terms referring to vitamin D or vitamin D deficiency, prevalence or cross-sectional studies, and countries or ethnicity. Titles and abstracts were reviewed to identify studies on population-based mean serum 25(OH)D concentrations among Turkish, Moroccan, Indian, and sub-Sahara African populations in Europe, Turkey, Morocco, India, and sub-Sahara Africa.

RESULTS

The vitamin D status of immigrant populations in Europe was poor compared to the indigenous European populations. The vitamin D status of studied populations in Turkey and India varied and was either similar to the immigrant populations in Europe (low) or similar to or even higher than the indigenous European populations (high).

CONCLUSIONS

In addition to observed negative consequences of low serum 25(OH)D concentrations among nonwestern populations, this overview indicates that vitamin D status in nonwestern immigrant populations should be improved. The most efficacious strategy should be the subject of further study.

BCG vaccination: a role for vitamin D?

Background

BCG vaccination is administered in infancy in most countries with the aim of providing protection against tuberculosis. There is increasing interest in the role of vitamin D in immunity to tuberculosis. This study objective was to determine if there was an association between circulating 25(OH)D concentrations and BCG vaccination status and cytokine responses following BCG vaccination in infants.

Methods

Blood samples were collected from UK infants who were vaccinated with BCG at 3 (n = 47) and 12 (n = 37) months post BCG vaccination. These two time-points are denoted as time-point 1 and time-point 2. Two blood samples were also collected from age-matched unvaccinated infants (n = 32 and 28 respectively), as a control group. Plasma vitamin D concentrations (25(OH)D) were measured by radio-immunoassay. The cytokine IFNγ was measured in supernatants from diluted whole blood stimulated with M.tuberculosis (M.tb) PPD for 6 days.

Results

58% of infants had some level of hypovitaminosis (25(OH)D <30ng/ml) at time-point 1, and this increased to 97% 9 months later. BCG vaccinated infants were almost 6 times (CI: 1.8–18.6) more likely to have sufficient vitamin D concentrations than unvaccinated infants at time-point 1, and the association remained strong after controlling for season of blood collection, ethnic group and sex. Among vaccinees, there was also a strong inverse association between IFNγ response to M.tb PPD and vitamin D concentration, with infants with higher vitamin D concentrations having lower IFNγ responses.

Conclusions

Vitamin D may play an immuno-regulatory role following BCG vaccination. The increased vitamin D concentrations in BCG vaccinated infants could have important implications: vitamin D may play a role in immunity induced by BCG vaccination and may contribute to non-specific effects observed following BCG vaccination.

Proceedings of the Rank Forum on Vitamin D

The Rank Forum on Vitamin D was held on 2nd and 3rd July 2009 at the University of Surrey, Guildford, UK. The workshop consisted of a series of scene-setting presentations to address the current issues and challenges concerning vitamin D and health, and included an open discussion focusing on the identification of the concentrations of serum 25-hydroxyvitamin D (25(OH)D) (a marker of vitamin D status) that may be regarded as optimal, and the implications this process may have in the setting of future dietary reference values for vitamin D in the UK. The Forum was in agreement with the fact that it is desirable for all of the population to have a serum 25(OH)D concentration above 25 nmol/l, but it discussed some uncertainty about the strength of evidence for the need to aim for substantially higher concentrations (25(OH)D concentrations>75 nmol/l). Any discussion of 'optimal' concentration of serum 25(OH)D needs to define 'optimal' with care since it is important to consider the normal distribution of requirements and the vitamin D needs for a wide range of outcomes. Current UK reference values concentrate on the requirements of particular subgroups of the population; this differs from the approaches used in other European countries where a wider range of age groups tend to be covered. With the re-emergence of rickets and the public health burden of low vitamin D status being already apparent, there is a need for urgent action from policy makers and risk managers. The Forum highlighted concerns regarding the failure of implementation of existing strategies in the UK for achieving current vitamin D recommendations.

Vitamin D status of HIV-infected women and its association with HIV disease progression, anemia, and mortality

BACKGROUND

Vitamin D has a potential role in slowing HIV disease progression and preventing mortality based on its extensive involvement in the immune system; however, this relationship has not been examined in large studies or in resource-limited settings.

METHODOLOGY/PRINCIPAL FINDINGS

Vitamin D levels were assessed in 884 HIV-infected pregnant women at enrollment in a trial of multivitamin supplementation (not including vitamin D) in Tanzania. Women were followed up for a median of 69.5 months, and information on hemoglobin levels, HIV disease progression, and mortality was recorded. Proportional hazard models and generalized estimating equations were used to assess the relationship of these outcomes with vitamin D status.

CONCLUSIONS/SIGNIFICANCE

Low vitamin D status (serum 25-hydroxyvitamin D<32 ng/mL) was significantly associated with progression to WHO HIV disease stage III or greater in multivariate models (incidence rate ratio [RR]: 1.25; 95% confidence intervals [CI]: 1.05, 1.50). No significant relationship was observed between vitamin D status and T-cell counts during follow-up. Women with low vitamin D status had 46% higher risk of developing severe anemia during follow-up, compared to women with adequate vitamin D levels (RR: 1.46; 95% CI: 1.09, 1.96). Women in the highest vitamin D quintile had a 42% lower risk of all-cause mortality, compared to the lowest quintile (RR: 0.58; 95% CI: 0.40, 0.84). Vitamin D status had a protective association with HIV disease progression, all-cause mortality, and development of anemia during follow-up in HIV-infected women. If confirmed in randomized trials, vitamin D supplementation could represent a simple and inexpensive method to prolonging the time to initiation of antiretroviral therapy in HIV-infected patients, particularly in resource-limited settings.

Possible Health Implications and Low Vitamin D Status during Childhood and Adolescence: An Updated Mini Review

Vitamin D deficiency is common in the developing countries and exists in both childhood and adult life. The great importance of Vitamin D is the moderation of calcium (Ca) and phosphorus (P) homeostasis as well as the absorption of Ca. While insufficiency of vitamin D is a significant contributing factor to risk of rickets in childhood, it is possible that a more marginal deficiency of vitamin D during life span contribute to osteoporosis as well as potentially to the development and various other chronic diseases such as cardiovascular disease, cancer and diabetes. This paper reviews the metabolism, epidemiology, and treatment of vitamin D and calcium insufficiency as well as its relation to various diseases during childhood and adolescence.

Nutritional rickets and vitamin D deficiency--association with the outcomes of childhood very severe pneumonia: a prospective cohort study

BACKGROUND

The association of rickets and vitamin D deficiency (VDD) with pneumonia is well documented, but not with its outcomes.

OBJECTIVES

To investigate whether rickets and VDD predict the outcomes in very severe pneumonia (VSP).

DESIGN

A prospective cohort study conducted at Al-Sabeen hospital in Sana'a, Yemen. A total of 152 children aged 2-59 months with WHO-defined VSP were enrolled, managed, and followed for up to 30 days. Treatment outcome was either successful or failure (antibiotic modification for clinical worsening, death, relapse after 10-day antibiotics, or development of complications). Serum vitamin D (25OHD) was measured in 79 cases. A concentration of <or=30 nmol/L defines VDD.

MAIN OUTCOME MEASURES

Association of rickets with treatment outcome; and VDD with the circulating neutrophils (PMNs), and oxygen saturation% (SpO(2)%), respectively.

RESULTS

Treatment failure occurred in 24 (15.8%), all aged 2-12 months, and 21 (87.5%) were rachitic. Of the 79 subset, 29 had VDD of which 23 (79.3%) had rickets. Treatment failure was significantly higher in the rachitic compared to non-rachitic [20.6% (21/102) vs. 6% (3/50); OR 1.38 (95% CI 1.13-1.69), P = 0.031]. In multivariate regression, rickets significantly predict a reduced successful treatment compared with non-rachitic [79.4% (81/102) vs. 94% (47/50); Adjusted OR 0.41 (95% CI 0.20-0.85); P = 0.02]. VDD was strongly associated with reduced PMNs% [Mean (SD) 37 (17) vs. 47 (17); Adjusted OR 0.71 (95% CI 0.53-0.95), P = 0.02], and reduced SpO(2)% [Mean (SD) 85.9 (7.9) vs. 89.8 (7.1); OR 0.96 (95% CI 0.93-0.99), P = 0.021].

CONCLUSIONS

In VSP, rickets was significantly associated with treatment outcome and VDD significantly predict both reduced circulating PMNs, and Day-5 hypoxemia (SpO(2)%, <88%).

Vitamin D deficiency in early childhood: prevalent in the sunny South Pacific

Objective

To estimate the prevalence of and risk factors for vitamin D deficiency in young urban children in Auckland, New Zealand, where there is no routine vitamin D supplementation.

Design

A random sample of urban children. Vitamin D deficiency was defined as serum 25-hydroxyvitamin D <27·5 nmol/l (<11 ng/ml). Logistic regression analysis was used to calculate odds ratios and, from these, relative risks (RR) and 95 % confidence intervals were estimated.

Setting

Auckland, New Zealand (36°52′S), where the daily vitamin D production by solar irradiation varies between summer and winter at least 10-fold.

Subjects

Children aged 6 to 23 months enrolled from 1999 to 2002.

Results

Vitamin D deficiency was present in forty-six of 353 (10 %; 95 % CI 7, 13 %). In a multivariate model there was an increased risk of vitamin D deficiency associated with measurement in winter or spring (RR = 7·24, 95 % CI 1·55, 23·58), Pacific ethnicity (RR = 7·60, 95 % CI 1·80, 20·11), not receiving any infant or follow-on formula (RR = 5·69, 95 % CI 2·66, 10·16), not currently receiving vitamin supplements (RR = 5·32, 95 % CI 2·04, 11·85) and living in a more crowded household (RR = 2·36, 95 % CI 1·04, 4·88).

Conclusions

Vitamin D deficiency is prevalent in early childhood in New Zealand. Prevalence varies with season and ethnicity. Dietary factors are important determinants of vitamin D status in this age group. Vitamin D supplementation should be considered as part of New Zealand’s child health policy.

The vitamin D connection to pediatric infections and immune function

Over the past 20 y, a resurgence in vitamin D deficiency and nutritional rickets has been reported throughout the world, including the United States. Inadequate serum vitamin D concentrations have also been associated with complications from other health problems, including tuberculosis, cancer (prostate, breast, and colon), multiple sclerosis, and diabetes. These findings support the concept of vitamin D possessing important pleiotropic actions outside of calcium homeostasis and bone metabolism. In children, an association of nutritional rickets with respiratory compromise has long been recognized. Recent epidemiologic studies clearly demonstrate the link between vitamin D deficiency and the increased incidence of respiratory infections. Further research has also elucidated the contribution of vitamin D in the host defense response to infection. However, the mechanism(s) by which vitamin D levels contribute to pediatric infections and immune function has yet to be determined. This knowledge is particularly relevant and timely, because infants and children seem more susceptible to viral rather than bacterial infections in the face of vitamin D deficiency. The connection among vitamin D, infections, and immune function in the pediatric population indicates a possible role for vitamin D supplementation in potential interventions and adjuvant therapies.

Vitamin D deficiency and supplementation during pregnancy

OBJECTIVE

Vitamin D is essential for skeletal health and prolonged deficiency results in infantile rickets and adult osteomalacia. The aim of this study is to determine the vitamin D status in pregnancy and to evaluate the effects of daily and of single-dose vitamin D supplementation.

DESIGN

A prospective randomized study at St Mary's Hospital London.

PATIENTS

A total of 180 women (Indian Asian, Middle Eastern, Black and Caucasian) were recruited at 27 weeks gestation and randomized into three treatment groups: a single oral dose of 200,000 IU vitamin D, a daily supplement of 800 IU vitamin D from 27 weeks until delivery and a no treatment group.

MEASUREMENTS

Vitamin D (25-hydroxyvitamin D), PTH and corrected calcium levels in mothers at 27 weeks and at delivery and cord 25-hydroxyvitamin D and corrected calcium levels.

RESULTS

The final maternal 25-hydroxyvitamin D levels were significantly higher in the supplemented group [daily dose (median) 42 (IQR 31-76) nmol/l, stat dose (median) 34 (IQR 30-46) nmol/l vs. median 27 (IQR 27-39) nmol/l in the no treatment; P < 0.0001] and significantly fewer women with secondary hyperparathyroidism in the supplemented group (10% in daily dose vs. 12% in stat dose vs. 27% in the no treatment; P < 0.05). Cord 25-hydroxyvitamin D levels were significantly higher with supplementation [daily dose median 26 (IQR 17-45) nmol/l, stat dose median 25 (IQR 18-34) nmol/l vs. median 17 (IQR 14-22) nmol/l in no treatment; P = 0.001].

CONCLUSION

Single or daily dose improved 25-hydroxyvitamin D levels significantly. However, even with supplementation, only a small percentage of women and babies were vitamin D sufficient. Further research is required to determine the optimal timing and dosing of vitamin D in pregnancy.

Vitamin D deficiency: a global perspective

The prevalence of clinical vitamin D deficiency (rickets and osteomalacia) is high in many parts of the world, and there is a resurgence of rickets among children of ethnic minority groups in Europe and Australasia. Plasma 25-hydroxyvitamin D concentration (25OHD) is a useful risk marker of clinical vitamin D deficiency. This review summarizes the factors that contribute to differences in 25OHD among populations and provides an overview of the prevalence of low vitamin D status worldwide. It discusses the controversies that surround the interpretation of 25OHD, other proposed indices of vitamin D adequacy and dietary reference values for vitamin D, and describes the emerging evidence that a very low calcium intake may contribute to the etiology of rickets in Africa and Asia. There is an urgent need for action to address the global burden of rickets and osteomalacia.

Higher prevalence of vitamin D deficiency is associated with immigrant background among children and adolescents in Germany

In recent years, a high prevalence of vitamin D deficiency among children and adolescents has been reported in countries with moderate climates. Those with an immigrant background living under these conditions are at especially high risk. To date, representative data in Germany is lacking. We analyzed 25-hydroxyvitamin D [25(OH)D] concentrations of 10,015 children and adolescents, aged 1-17 y, who participated in the German National Health Interview and Examination Survey for Children and Adolescents. The proportion of immigrants was 25.4%, corresponding well to their percentage of the population. Among 3- to 17-y-old participants, 29% of immigrant boys and 31% of immigrant girls had 25(OH)D concentrations <25 nmol/L (severe to moderate vitamin D deficiency) compared with 18% of nonimmigrant boys and 17% of nonimmigrant girls. Furthermore, 92% of immigrant boys and 94% of immigrant girls had 25(OH)D concentrations <75 nmol/L (levels above 75 nmol/L are defined as optimal regarding various health outcomes) compared with 87% of nonimmigrants. Boys with a Turkish or Arab-Islamic background had an increased risk of having 25(OH)D concentrations <25 nmol/L compared with nonimmigrants (odds ratio [OR] 2.3; [95% CI] 1.4-3.8 and OR 7.6; [95% CI] 3.0-19.1). The same was true for girls with a Turkish (OR 5.2; [95% CI] 2.9-9.6), Arab-Islamic (OR 5.9; [95% CI] 2.5-14.0), Asian (OR 6.7; [95% CI] 2.2-19.8), or African (OR 7.8; [95% CI] 1.5-40.8) background. Supplementation of vitamin D beyond infancy, especially in high-risk groups, or fortification of food should be considered.

Vitamin D deficiency in children and adolescents: epidemiology, impact and treatment

Vitamin D deficiency is highly prevalent among children and adolescents worldwide. The high rates of vitamin D deficiency during childhood are of major public health relevance, given the growing evidence that vitamin D deficiency may play a key role in the pathophysiology of many chronic diseases beyond rickets, including autoimmune conditions, cardiovascular diseases, and cancer. Identification, treatment, and prevention of vitamin D deficiency in childhood may therefore have profound health effects throughout the life span. In this review, we discuss the definitions, epidemiology, clinical implications, and treatment of vitamin D deficiency in children and adolescents.

Vitamin D, glucose, insulin, and insulin sensitivity

This review examines available evidence of links between abnormalities of glucose and insulin metabolism and vitamin D deficiency. Possible mechanisms of action of vitamin D include stimulation of insulin secretion and effects on insulin sensitivity. Sun exposure usually implies greater outdoor physical activity, which in itself may have beneficial effects on insulin sensitivity, unrelated to serum 25-hydroxyvitamin D concentrations. The observed associations in humans among vitamin D, insulin, and glucose metabolism have not yet been confirmed by intervention studies and, hence, a causal association has not been established. Clinical trials are needed to determine whether vitamin D treatment of vitamin D-deficient individuals is able to prevent or treat diabetes mellitus.

Nutritional problems related to food allergy in childhood

Food allergy is becoming an increasing problem worldwide with an estimated 6-8% of children affected at some point in their childhood. The perceived prevalence of food allergy is even higher with an estimated 20% of children adhering to some form of elimination diet. Against this background, accurate diagnosis is essential to prevent the imposition of unnecessarily restrictive diets on young children. Raising clinical awareness amongst health professionals as to the clinical characteristics, epidemiology, investigation, and management of food allergic disorders is key to tackling this growing problem. In this article, three separate cases of children with poor nutrition and secondary morbidity are presented, highlighting the varying scenarios in which these conditions can be encountered. In the first child, the features clinically displayed were hypocalcemic seizures and rickets due to prolonged breast feeding, poor weaning, and inadequate dietary supplementation. The second case reveals the dangers of complementary diagnostic allergy testing leading to poor nutrition as a consequence of an unsupervised elimination diet. The last report describes a child with multiple food allergies, failure to thrive, and protein losing enteropathy to highlight the diversity of nutritional problems faced by allergists and to underline the importance of specialist dietetic input in the management of a child with food allergy.

[Biochemical measures in the German Health Interview and Examination Survey for Children and Adolescents (KiGGS)]

In the framework of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS) a variety of biochemical parameters was determined in order to provide objective information on health status and particular health risks, in addition to parent interview data and anthropometric measurements. Overall 43 parameters covered three areas of particular public health interest: micronutrient deficiency, seroepidemiology of infectious diseases and immunization status, and risk indicators or risk factors for chronic non-communicable diseases. A review of available evidence regarding valid reference or cutoff values as well as the standardization of laboratory methods led to the categorization of these parameters into five classification categories. Here, we discuss the present first descriptive results on selected parameters representing the various categories. In order to determine the public health impact of measurement results, and perhaps even derive normative reference data relevant to health care, more detailed analyses will be required. In the first step, these will focus on cross-sectional analyses of the association between biochemical parameters and other health-related anthropometric and sociodemographic variables. Intermediate and long-term objectives will include the construction of multidimensional reference values taking into account several laborato ry data and other clinical information at the same time, and the prognostic validation of reference or cut-off values based on a follow- up of the study participants for clinical outcomes.

Population prevalence and risk factors for iron deficiency in Auckland, New Zealand

AIM

Previous prevalence estimates of iron deficiency (ID) in young New Zealand children are inaccurate because of sampling bias and imprecise definition of ID. The aim of this study was to estimate the prevalence of ID in children aged 6-23 months and the factors associated with ID.

METHODS

An ethnically stratified sample identified from random residential address start points. Children resident in Auckland, New Zealand were enrolled from 1999 to 2002. Children with elevated C-reactive protein (>4 mg/L) were excluded. Iron status was determined in 324 (78%) of 416 enrolled children. Analyses adjusted for clustering and weighted for ethnic stratification. ID defined as abnormal values for two or more of serum ferritin (<10 microg/L), iron saturation (<10%) and mean cell volume (<73 fl).

RESULTS

ID was present in 14% (95% confidence interval (CI) 9-17%). ID prevalence varied with ethnicity (Maori 20%, Pacific 17%, other 27%, New Zealand European 7%, P = 0.005), but not with social deprivation. In a multivariate analysis that adjusted for low birthweight, there was an increased risk of ID associated with a body mass index >or= 18.5 kg/m(2) (RR = 4.34, 95% CI 1.08-10.67), and with receiving no infant or follow on formula (RR = 3.60, 95% CI 1.56-6.49).

CONCLUSIONS

ID is prevalent in young New Zealand children. Variance in ID prevalence with ethnicity but not social deprivation implies that cultural practices influence iron status. Young children with more rapid growth are at increased risk of ID as are those receiving milk other than that specifically modified for them.

Vitamins for babies and young children

The Welfare Food Scheme has recently been reviewed, and, although changes are being made, free vitamin supplements for children <4 years old will remain an important part of the new "Healthy Start" scheme. Establishing precise daily requirements for vitamins is not easy, and there is considerable individual variation; however, achieving the reference nutrient intake (RNI) should be possible with a healthy balanced diet for all except vitamins K and D, which require additional physiological or metabolic processes. For vitamin K, there is a well-established neonatal supplementation programme, and clinical deficiency is extremely rare. For vitamin D, however, supplementation is inconsistent, and both clinical and subclinical deficiencies are not uncommon in young children in the UK, particularly infants of Asian and Afro-Caribbean ethnic origin, and those who have prolonged exclusive breast feeding and delayed weaning. Most vitamin supplements contain vitamins A, C and D, with or without some of the B group of vitamins. There is clinical and dietary evidence to support vitamin D supplementation and some evidence from dietary surveys that vitamin A intakes may be low; however, there is no evidence to support supplementation of diets of UK children with water-soluble vitamins. Future strategy should aim at education of the public and health professionals regarding dietary intake and physiological aspects of vitamin sufficiency, as well as increasing awareness and availability of supplements, particularly of vitamin D, for those at increased risk of deficiency.

"The English disease" or "Asian rickets"? Medical responses to postcolonial immigration

Do the former colonizing powers, like their former colonies, have "postcolonial medicine," and if so, where does it take place, who practices it, and upon whom? How has British medicine in particular responded to the huge cultural shifts represented by the rise of the New Commonwealth and associated postcolonial immigration? I address these questions through a case study of the medical and political responses to vitamin D deficiency among Britain's South Asian communities since the 1960s. My research suggests that in these contexts, diet frequently became a proxy or shorthand for culture (and religion, and race), while disease justified pressure to assimilate.

Vitamin D deficiency: prevention or treatment?

BACKGROUND

Vitamin D deficiency is a chronic condition which contributes to general ill health and seems to be re-emerging in our catchment area since funding of vitamin D supplementation by Primary Care Trusts ceased. This study aims to verify this situation and to assess the cost effectiveness of reintroducing vitamin D supplementation in the Burnley Health Care NHS Trust.

METHODS

Vitamin D deficient patients presenting between January 1994 and May 2005 were identified and data retrospectively collected from their case notes. The cost of treatment and the theoretical cost of primary prevention for the Trust population were calculated using previous and current DoH guidelines.

RESULTS

Fourteen patients were identified, of whom 86% presented in the last 5 years and 93% were of Asian origin. The incidence of vitamin D deficiency for our population is 1 in 923 children overall and 1 in 117 in children of Asian origin. The average cost of treatment for each such child is pound2500, while the theoretical cost of prevention of vitamin D deficiency in the Asian population through primary prevention according to COMA guidance is pound2400 per case.

CONCLUSIONS

Vitamin D deficiency is re-emerging in our Trust. The overwhelming majority of our patients are of Asian origin. The cost of primary prevention for this high risk population compares favourably both medically and financially with treatment of established disease. We suggest that Primary Care Trusts provide funds for vitamin D supplementation of Asian children for at least the first 2 years of life.