Serum 25-hydroxyvitamin D status of adolescents and adults in two seasonal subpopulations from NHANES III

Vitamin D deficiency in minority populations

OBJECTIVE

Black and Hispanic individuals synthesize less vitamin D per unit of sun exposure than white individuals. The relationship between UV radiation and vitamin D insufficiency in minorities has not been well explored.

DESIGN

Prospective cohort study.

SETTING

Using the National Health and Nutrition Examination Survey, we obtained serum vitamin D levels for non-Hispanic Whites, Hispanics and non-Hispanic Blacks aged ≥18 years from 2000-2006. We linked these data with the average monthly solar UV index by census tract and data on sun exposure, vitamin D supplementation, health and demographics. We used multivariable regression analyses to assess vitamin D deficiency (<15 ng/ml) and insufficiency (<20 ng/ml) in January (when the UV index was lowest) by race/ethnicity and geography.

SUBJECTS

Adults (n 14,319) aged ≥18 years.

RESULTS

A 1-point increase in the UV index was associated with a 0·51 ng/ml increase in vitamin D (95% CI 0·35, 0·67 ng/ml; P<0·001). Non-Hispanic Black race and Hispanic ethnicity were associated with a 7·47 and 3·41 ng/ml decrease in vitamin D, respectively (both P<0·001). In January, an estimated 65·4% of non-Hispanic Blacks were deficient in vitamin D, compared with 28·9% of Hispanics and 14·0% of non-Hispanic Whites. An estimated 84·2% of non-Hispanic Blacks were insufficient in vitamin D v. 56·3% of Hispanics and 34·8% of non-Hispanic Whites. More non-Hispanic Blacks were estimated to be deficient in vitamin D in January in the highest UV index quartile than were non-Hispanic Whites in the lowest UV index quartile (60·2% v. 25·7%).

CONCLUSIONS

Wintertime vitamin D insufficiency is pervasive among minority populations, and not uncommon among non-Hispanic Whites.

Relationship between 25-hydroxyvitamin D concentrations, serum calcium, and parathyroid hormone in apparently healthy Syrian people

Vitamin D deficiency (25-hydroxyvitamin D (25OHD) <25 nmol/L) was common in a convenience sample of apparently healthy Syrian adults. Female gender, season, and concealing clothing were independent predictors of vitamin D deficiency. Community-based research is needed to identify vulnerable subgroups and inform public health actions.

PURPOSE

Optimal vitamin D status for bone health has been inferred from the determination of serum 25OHD levels below which there is an increase in serum parathyroid hormone (PTH). Studies worldwide showed high prevalence of hypovitaminosis D even in sunny countries. There is little evidence about its prevalence among Syrian adult population. We aimed to assess the serum levels of 25OHD and factors related to vitamin D inadequacy and its relation to serum PTH and calcium among apparently healthy adults.

METHODS

Serum 25OHD and PTH measurements were obtained from 372 subjects aged 18-62 years living in Damascus and its surroundings, between April 2011 and March 2013. Binary logistic regression was used to assess risk factors for hypovitaminosis D.

RESULTS

The mean (standard deviation (SD)) 25OHD level was 24.7 (16.9) nmol/L [9.8 (6.7) ng/mL] and was higher in men than women (p < 0.001). Levels <25, <50, and <75 nmol/L were detected in 61, 90.1, and 99.2 % of the participants, respectively. Season influenced vitamin D status in men but not in women (p < 0.001). Female gender and wearing the veil (hijab) were independent predictors of vitamin D deficiency (25OHD <25 nmol/L). PTH was significantly higher below this threshold (p < 0.001). Serum 25OHD <25 nmol/L, sex, and age ≥ 35 years were statistically significant factors for PTH elevation.

CONCLUSIONS

Vitamin D deficiency was highly prevalent in our sample. Further research is needed to identify population groups vulnerable for hypovitaminosis D and specify its predictors and inform the necessary public health measures.

Vitamin D intakes of adults differ by income, gender and race/ethnicity in the U.S.A., 2007 to 2010

OBJECTIVE

To determine if dietary, supplemental and total vitamin D intakes in the USA are influenced by income, race/ethnicity or gender.

DESIGN

Cross-sectional. US vitamin D intakes were estimated by poverty income ratio (PIR), race/ethnicity and gender using 24 h dietary intake recalls and dietary supplement use questionnaires. Statistical analyses of weighted data were performed using SAS (version 9.2) to estimate means and their standard errors. Race and ethnic intake differences controlling for PIR, gender and age were assessed by ANCOVA.

SUBJECTS

Adults aged ≥19 years.

SETTING

The 2007-2010 National Health and Nutrition Examination Survey, USA.

RESULTS

Total (dietary and supplement) vitamin D intake was greater in the high (10.0 (se 0.30) μg/d) v. the medium (7.9 (se 0.3) μg/d) or the low (8.0 (se 0.3) μg/d) PIR categories. Total vitamin D intake of non-Hispanic Whites (10.6 (se 0.4) μg/d) was greater than that of Hispanics (8.1 (se 0.3) μg/d) and non-Hispanic Blacks (7.1 (se 0.3) μg/d). Supplemental vitamin D intake was greater by females (5.3 (se 0.2) μg/d) than by males (3.3 (se 0.2) μg/d). Participants with high income were more likely to be vitamin D supplement users (33.0%) than those with medium (22.5%) or low (17.6%) income. High-income non-Hispanic Whites had the lowest percentage (57%) not meeting the Estimated Average Requirement for vitamin D. Fortified milk and milk products provided 43.7% of the dietary vitamin D intake.

CONCLUSIONS

Public health efforts should expand the number of vitamin D-fortified foods and encourage the consumption of foods high in vitamin D and use of supplements.

Vitamin D3 dose requirement to raise 25-hydroxyvitamin D to desirable levels in adolescents: results from a randomized controlled trial

Several organizations issued recommendations on desirable serum 25-hydroxy vitamin D [25(OH)D] levels and doses of vitamin D needed to achieve them. Trials allowing the formulation of evidence-based recommendations in adolescents are scarce. We investigated the ability of two doses of vitamin D3 in achieving recommended vitamin D levels in this age group. Post hoc analyses on data from a 1-year double-blind trial that randomized 336 Lebanese adolescents, aged 13 ± 2 years, to placebo, vitamin D3 at 200 IU/day (low dose), or 2000 IU/day (high dose). Serum 25(OH)D level and proportions of children achieving levels ≥ 20 ng/mL and 30 ng/mL were determined. At baseline, mean 25(OH)D was 15 ± 7 ng/mL, 16.4 ± 7 ng/mL in boys, and 14 ± 8 ng/mL in girls, p=0.003, with a level ≥ 20 ng/mL in 18% and ≥ 30 ng/mL in 5% of subjects. At 1 year, mean levels were 18.6 ± 6.6 ng/mL in the low-dose group, 17.1 ± 6 ng/mL in girls, and 20.2 ± 7 ng/mL in boys, p=0.01, and 36.3 ± 22.3 ng/mL in the high-dose group, with no sex differences. 25(OH)D increased to ≥ 20 ng/mL in 34% of children in the low-dose and 96% in the high-dose group, being higher in boys in the low-dose arm only; it remained ≥ 30 ng/mL in 4% of children in the low-dose arm but increased to 64% in the high-dose arm. Baseline 25(OH)D level, body mass index (BMI), and vitamin D dose assigned were the most significant predictors for reaching a 25(OH)D level ≥ 20 ng/mL and 30 ng/mL. A daily dose of 2000 IU raised 25(OH)D level ≥ 20 ng/mL in 96% of adolescents (98% boys versus 93% girls). Dose-response studies are needed to determine in a definitive manner the daily allowance of vitamin D for Middle Eastern adolescents with a similar profile.

The effectiveness of a short food frequency questionnaire in determining vitamin D intake in children

Previous studies have found a high prevalence of vitamin D deficiency in children, yet few validated dietary vitamin D assessment tools are available for use in children. Our objective was to determine whether a short food frequency questionnaire (SFFQ) can effectively assess vitamin D intake in children. Vitamin D intake ascertained by a SFFQ was compared with assessments by a previously validated long food frequency questionnaire (LFFQ) in a population of 296 healthy 6- to 14-y-old children (54% male, 60% African American) from Pittsburgh, PA. The questionnaires were completed at two points 6 mo apart. Median reported daily vitamin D intake from the SFFQ (baseline: 380 IU, follow-up: 363 IU) was higher than the LFFQ (255 IU and 254 IU, respectively). Reported median dairy intake, including milk, cheese, and yogurt, was 3.7 cups/day, which meets the USDA recommendation for children. Vitamin D intake reported by the 2 questionnaires was modestly correlated at baseline and follow-up (r = 0.35 and r = 0.37, respectively; p < 0.001). These associations were stronger in Caucasians (r = 0.48 and r = 0.49, p < 0.001) than in African Americans (r = 0.27 and r = 0.31; p = 0.001). The sensitivity of the SFFQ for predicting daily vitamin D intake, defined as intake of ≥ 400 IU on both the SFFQ and LFFQ, was 65%. Specificity, defined as intake of < 400 IU on both questionnaires, was 42%. Vitamin D requirements may not be met despite adequate consumption of dairy products. The SFFQ was found to be a modestly valid and sensitive tool for dietary assessment of vitamin D intake in children.

Serum 25(OH)D response to vitamin D3 supplementation: a meta-regression analysis

OBJECTIVE

The aim of this study was to review factors that influence serum 25(OH)D when patients are given vitamin D supplements.

METHODS

From a comprehensive search of all randomized controlled clinical trials with vitamin D3 supplementation available on PubMed up to November 2011, we selected 33 with 43 treatment arms that included at least 30 adult participants. The achieved pooled mean difference (PMD) and 95% confidence intervals (CIs) were calculated using the random-effects models. Meta-regression and subgroup analyses were performed for prespecified factors, including dose, duration, baseline serum 25(OH)D, and age.

RESULTS

With a mean baseline serum 25(OH)D of 50.4 nmol/L, PMD was 37 nmol/L (95% CI, 33-41) with significant heterogeneity among studies. Dose (slope: 0.006; P < 0.001), trial duration (slope: 0.21; P < 0.001), baseline serum 25(OH)D (slope: -0.19; P < 0.001), and age (slope: 0.42; P < 0.001) independently influenced vitamin D response. Similar results were found in studies with a mean baseline serum 25(OH)D <50 nmol/L. In subgroup analyses, the PMD was higher with doses ≥800 IU/d (39.3 nmol/L) after 6 to 12 mo (41.7 nmol/L), with baseline 25(OH)D <50 nmol/L (39.6 nmol/L), and in adults aged >80 y (40.5 nmol/L).

CONCLUSION

This meta regression indicates that a higher increase in serum levels of 25(OH)D in adults is found with a dose of ≥800 IU/d, after at least 6 to 12 mo, and even when baseline 25(OH)D is low and in adults >80 y.

Vitamin D insufficiency is associated with lower physical function in patients with heart failure and diabetes

Vitamin D deficiency is frequent among patients with heart failure (HF) and diabetes, disorders associated with exercise intolerance and muscle weakness. This study aims to search for associations between vitamin D sufficiency and physical function indexes in patients with HF and diabetes. A cross-sectional study of 146 HF patients, 39.7% with diabetes, at a Brazilian tertiary outpatient clinic was performed. Patients underwent clinical evaluation, 6-minute walk test (6 MWT), handgrip strength, physical activity level (IPAQ), and biochemical evaluations including serum 25-hydroxyvitamin D. Classification was done according to vitamin D status (≥ 30 ng/dL, sufficient) and presence/absence of diabetes in vitamin sufficient, no diabetes (DS-C, n = 25), vitamin sufficient, diabetes (DS-DM, n = 18), vitamin deficient, no diabetes (DD-C, n = 63), and vitamin deficient, diabetes (DD-DM, n = 40). Patients age was 55.4 ± 8 yrs; 70.5% had vitamin D deficiency. Clinical characteristics were similar among groups. Total time expended in physical activity was similar among groups (P = 0.26). DS-C covered higher distances in the 6 MWT (392 ± 60 m) versus DD-DM (309 ± 116 m); P = 0.024. Handgrip strength was similar among groups but tended to lower levels in DD-DM (P = 0.074) even after being adjusted to physical activity (P = 0.069). Vitamin D deficiency can influence physical function in HF diabetic patients.

Prevalence of 25-hydroxyvitamin D deficiency in Korean adolescents: association with age, season and parental vitamin D status

OBJECTIVE

We aimed to assess the prevalence and associated factors of vitamin D deficiency in healthy adolescents and to determine parent-adolescent association in vitamin D status.

DESIGN

A cross-sectional study.

SETTING

Data from the Korean National Health and Nutrition Examination Survey (KNHANES) 2008-2009. Serum 25-hydroxyvitamin D (25(OH)D) levels were measured using 125I-labelled RIA kits. Vitamin D deficiency in adolescents was defined as 25(OH)D level <27·5 nmol/l, and 25(OH)D levels between 27·5 and <50 nmol/l were considered insufficient. For the parents, vitamin D deficiency was defined as 25(OH)D level <50 nmol/l.

SUBJECTS

The study population consisted of 2062 adolescents (1095 boys, 967 girls; aged 10-18 years) and their parents (1005 fathers, 1341 mothers).

RESULTS

Overall, 13·4% of adolescents (boys 11·7%, girls 15·4%) were 25(OH)D deficient, 54·7% were 25(OH)D insufficient. Prevalence of vitamin D deficiency increased with age (P < 0·0001). Parental vitamin D deficiency was more prevalent in vitamin D-deficient adolescents than in non-deficient adolescents (all P < 0·0001). In multivariate logistic regression analyses, predictors for vitamin D deficiency were senior high school students (OR = 3·45-4·33), winter/spring season (OR = 3·18-5·11/5·35-7·36) and parental vitamin D deficiency (OR = 1·78-4·88; all P < 0·05).

CONCLUSIONS

Vitamin D insufficiency is prevalent among healthy Korean adolescents and the parent-offspring association warrants vitamin D screening for family members of deficient individuals.

Association between vitamin D and Apo B concentrations in Argentinean Indian children

OBJECTIVE

The objective of the study was to determine the prevalence of vitamin D insufficiency and its association with non-traditional cardiovascular disease (CVD) risk factors such as Apo B in South American Indian school children.

METHODS

A cross-sectional study of 355 children (166 Males) aged 9.6±2.3 y was performed. Anthropometric measures, glucose, lipids, insulin, Apo B, Apo A, and vitamin D concentrations were measured.

RESULTS

The prevalence of overweight and obesity was 10.7% (38) per CDC. One child (0.3%) had optimal vitamin D concentrations [25(OH)D[>30 ng/ml. Univariate analysis showed significant associations between vitamin D and HDL-C (r=0.12 p<0.05), age (r=-0.11 p<0.05) BMI (r=-0.22 p<0.05), LDL-C (r=-0.22 p<0.01), triglycerides (r=-0.16 p<0.01), non HDL-C (r=-0.21 p<0.01), Apo B (r=-0.23 p<0.01), Apo B/Apo A (r=-0.21 p<0.01), insulin (r=-0.17 p<0.05), and HOMA-IR (r=-0.16 p<0.05). Multiple linear regression analysis showed that female gender and Apo B were significantly associated with vitamin D adjusted for confounding factors (R(2) 0.12).

CONCLUSION

Vitamin D deficiency was associated with increased Apo B among Indian children, suggesting that it could be used as a risk marker of CVD.

Relationship between serum 25-hydroxyvitamin D and parathyroid hormone in the search for a biochemical definition of vitamin D deficiency in children

BACKGROUND

Current guidelines use differing definitions of vitamin D deficiency based on serum 25-hydroxyvitamin D (25OHD) levels, which complicates clinical decision making on vitamin D doses used for the prevention and treatment. This study examined the natural relationship between serum 25OHD, parathyroid hormone (PTH), calcium, phosphate, and alkaline phosphatase.

METHODS

Two-hundred and fourteen children routinely admitted without conditions affecting the natural relationship among metabolites, including 17 with radiologically confirmed vitamin D deficiency rickets, were studied. The frequency of abnormal bone metabolites was examined for different 25OHD thresholds.

RESULTS

The best fitting intersection point where PTH levels increased was a 25OHD level of 34 nmol/l (R(2) = 0.454; 95% confidence interval: 27-41 nmol/l). Seventy-three and 86% of the children demonstrated some biochemical abnormality below 25OHD levels of 41 and 27 nmol/l, respectively. All patients with rickets had 25OHD levels < 34 nmol/l. The vast majority of children with abnormal bone metabolites had 25OHD levels < 34 nmol/l and PTH levels > 50 ng/l.

CONCLUSION

Vitamin D deficiency, based on PTH elevation, was best defined by a 25OHD level of < 34 nmol/l. Because deficient calcium supply often coexists with vitamin D deficiency and both can independently cause nutritional rickets, a threshold for the skeletal effects of vitamin D should not be based purely on 25OHD levels.

Vitamin D deficiency in first episode psychosis: a case-control study

BACKGROUND

Vitamin D deficiency is seen in a high proportion of people with established psychotic disorders, but it is not known if this is present at onset of the illness. We set out to examine vitamin D levels in people with their first episode of psychosis (FEP).

METHOD

We conducted a matched case-control study to examine vitamin D levels and rates of vitamin D deficiency in sixty nine patients presenting with their FEP and sixty nine controls matched for age, sex and ethnicity. Differences between groups were tested using student's-t tests, paired t-tests and odds ratios for further analysis.

RESULTS

Vitamin D levels were significantly lower in cases than in controls (p<0.001). The odds ratio of being vitamin D deficient was 2.99 in the FEP group relative to the control group. There was no correlation between vitamin D levels and length of hospitalisation in the patient group (r=-0.027, p=0.827).

CONCLUSIONS

We found higher rates of vitamin D deficiency in people with FEP compared to matched controls. Given that vitamin D is neuroprotective; that developmental vitamin D deficiency may be a risk factor for psychosis, and that incipient psychosis may affect lifestyle factors and diet, future studies are required to examine this association further. In the meantime, there is a need for more widespread testing of vitamin D levels in FEP and for the development of appropriate management strategies.

Vitamin D status and bone mineral density in African American children with Crohn disease

BACKGROUND

Vitamin D deficiency and low bone mineral density (BMD) are complications of inflammatory bowel disease. Vitamin D deficiency is more prevalent among African Americans compared with whites. There are little data comparing differences in serum 25-hydroxyvitamin D (25OHD) concentrations and BMD between African American and white children with Crohn disease (CD).

METHODS

We compared serum 25OHD concentrations of African American children with CD (n = 52) to white children with CD (n = 64) and healthy African American controls (n = 40). We also analyzed BMD using dual-energy x-ray absorptiometry results from our pediatric CD population.

RESULTS

African American children with CD had lower serum 25OHD concentrations (16.1 [95% confidence interval, CI 14.5-17.9] ng/mL) than whites with CD (22.3 [95% CI 20.2-24.6] ng/mL; P < 0.001). African Americans with CD and controls exhibited similar serum 25OHD concentration (16.1 [95% CI 14.5-17.9] vs 16.3 [95% CI 14.4-18.4] ng/mL; NS). African Americans with CD exhibited no difference in serum 25OHD concentration when controlling for seasonality, disease severity, and surgical history, although serum 25OHD concentration was significantly decreased in overweight children (body mass index ≥85%, P = 0.003). Multiple regression analysis demonstrated that obese African American girls with CD had the lowest serum 25OHD concentrations (9.6 [95% CI 6.8-13.5] ng/mL). BMD was comparable between African American and white children with CD (z score -0.4 ± 0.9 vs -0.7 ± 1.2; NS).

CONCLUSIONS

African American children with CD are more likely to have vitamin D deficiency compared with white children with CD, but have similar BMD. CD disease severity and history of surgery do not affect serum 25OHD concentrations among African American children with CD. African American children have low serum 25OHD concentrations, independent of CD, compared with white children. Future research should focus on how race affects vitamin D status and BMD in children with CD.

Calcidiol [25(OH)D3]: from diagnostic marker to therapeutical agent

OBJECTIVE

Osteoporosis is a skeletal disorder characterized by diminished bone strength, which results in an increased risk of fracture. Currently, osteoporosis is a public health priority due to the large number of individuals affected and the detrimental effect on quality of life. Primary osteoporosis, the most common form, usually results from age-related reduction in bone mineral strength. Over time, the individual's capacity to build bone is impaired, as the synthesis of vitamin D, the hormone responsible for calcium absorption, tends to decline. As serum calcium levels decrease, metabolic control serves to increase the removal of calcium from the skeleton to make up for the deficit. The synthesis of the 'hormone' vitamin D and its control therefore become central to intervention in involutional osteoporosis syndromes. In humans, plain vitamin D (cholecalciferol), also called parental or native vitamin D, is photosynthesized in the skin and then hydroxylated in the liver into the vitamin D analog calcidiol [25(OH)D3], which is hydroxylated again in the kidney into the vitamin D analog calcitriol [1,25(OH)2D3]. The advantage of administering vitamin D analogs is that the pro-drug calcidiol avoids the effect of declines in hepatic function, while calcitriol avoids the effect of declines in hepatic and kidney function. A strategy to enhance [25(OH)D3] levels to the optimal threshold of vitamin D is supplementation with the calcidiol metabolite itself. The goal of this paper is to review published studies on the efficacy of the calcidiol metabolite in increasing 25(OH)D3 serum levels and improving skeletal health parameters in humans.

METHODS

A library search of published papers in the area of use of calcidiol in humans from 1967 to 2013 was performed (key words: calcidiol, 25-hydroxy-vitamin D3, vitamin D supplementation, vitamin D metabolism, osteomalacia).

RESULTS AND CONCLUSION

The results of the survey made it possible to conclude that calcidiol is characterized by a number of features that make the compound ideal in conditions that require supplementation with a 25-hydroxylated metabolite.

The association between vitamin D and cognition: a systematic review

Vitamin D insufficiency and deficiency are a major health care problem. The association between vitamin D levels and cognitive function is still under debate. We conducted a systematic review to assess the association between levels of vitamin D and cognition. Therefore, the databases of Embase and Pubmed were searched through June 2012 for observational studies relating vitamin D levels to cognition. Our initial search yielded 2182 articles. After applying exclusion criteria, there were 28 studies eligible for inclusion: 25 cross-sectional and 6 prospective studies (3 studies show cross-sectional as well as prospective data). The main finding of the 25 cross-sectional studies was a statistically significant worse outcome on one or more cognitive function tests or a higher frequency of dementia with lower vitamin D levels or intake in 18 out of 25 (72%) studies, whereas 7 (28%) studies failed to show an association. Four out of 6 (66.7%) prospective studies showed a higher risk of cognitive decline after a follow-up period of 4-7 years in participants with lower vitamin D levels at baseline. In conclusion, this review supports the hypothesis that hypovitaminosis D is associated with worse outcome on one or more cognitive function tests or a higher frequency of dementia in cross-sectional as well as prospective studies. Further studies should focus on the role of vitamin D supplementation in the prevention of cognitive decline in participants with low vitamin D levels.

Linking vitamin d deficiency to inflammatory bowel disease

Inflammatory bowel disease is associated with industrialization, and its incidence has increased markedly over time. The prospect of reversing these trends motivates the search for the agent(s) involved. Modernity entails several physical and behavioral modifications that compromise both the photosynthesis of cholecalciferol in the skin and of its bioavailability. Although deficiency in this "vitamin" has therefore emerged as a leading candidate, and despite the publication of a randomized control trial that showed a trend toward statistically significant benefit in Crohn's disease, its causal agency has yet to be demonstrated by an adequately powered study. We discuss the strengths and weaknesses of the case being made by epidemiologists, geneticists, clinicians, and basic researchers, and consolidate their findings into a model that provides mechanistic plausibility to the claim. Specifically, converging data sets suggest that local activation of vitamin D coordinates the activity of the innate and adaptive arms of immunity, and of the intestinal epithelium, in a manner that promotes barrier integrity, facilitates the clearance of translocated flora, and diverts CD4 T cell development away from inflammatory phenotypes. Because smoking is an important risk-altering exposure, we also discuss its newly established melanizing effect and other emerging evidence linking tobacco use to immune function through vitamin D pathways.

A systematic review of vitamin D status in populations worldwide

Vitamin D deficiency is associated with osteoporosis and is thought to increase the risk of cancer and CVD. Despite these numerous potential health effects, data on vitamin D status at the population level and within key subgroups are limited. The aims of the present study were to examine patterns of 25-hydroxyvitamin D (25(OH)D) levels worldwide and to assess differences by age, sex and region. In a systematic literature review using the Medline and EMBASE databases, we identified 195 studies conducted in forty-four countries involving more than 168 000 participants. Mean population-level 25(OH)D values varied considerably across the studies (range 4·9-136·2 nmol/l), with 37·3 % of the studies reporting mean values below 50 nmol/l. The highest 25(OH)D values were observed in North America. Although age-related differences were observed in the Asia/Pacific and Middle East/Africa regions, they were not observed elsewhere and sex-related differences were not observed in any region. Substantial heterogeneity between the studies precluded drawing conclusions on overall vitamin D status at the population level. Exploratory analyses, however, suggested that newborns and institutionalised elderly from several regions worldwide appeared to be at a generally higher risk of exhibiting lower 25(OH)D values. Substantial details on worldwide patterns of vitamin D status at the population level and within key subgroups are needed to inform public health policy development to reduce risk for potential health consequences of an inadequate vitamin D status.

An analysis of the association between the vitamin D pathway and serum 25-hydroxyvitamin D levels in a healthy Chinese population

Vitamin D deficiency has been recognized as a major public health issue worldwide. Recent studies have indicated that genetic factors might play an important role in determining serum 25-hydroxyvitamin D [25(OH)D] levels in Caucasians and African Americans. However, the genes that contribute to the variation in serum 25(OH)D levels in Chinese are unknown. In this study, we screened 15 key genes within the vitamin D metabolic pathway using 96 single-nucleotide polymorphism (SNP) markers in a group of 2897 unrelated healthy Chinese subjects. Significant confounding factors that may influence the variability in serum 25(OH)D levels were used as covariates for association analyses. An association test for quantitative traits was performed to evaluate the association between candidate genes and serum 25(OH)D levels. In the present study, variants and/or haplotypes in GC, CYP2R1, and DHCR7/NADSYN1 were identified as being associated with 25(OH)D levels. Participants with three or four risk alleles of the two variants (GC-rs4588 and CYP2R1-rs10766197) had an increased chance of presenting with a 25(OH)D concentration lower than 20 ng/mL (odds ratio 2.121, 95% confidence interval 1.586-2.836, p = 6.1 × 10(-8) ) compared with those lacking the risk alleles. Each additional copy of a risk allele was significantly associated with a 0.12-fold decrease in the log-25(OH)D concentration (p = 3.7 × 10(-12) ). Haplotype TGA of GC rs705117-rs2282679-rs1491710, haplotype GAGTAC of GC rs842999-rs705120-rs222040-rs4588-rs7041-rs10488854, haplotype CA of GC rs1155563-rs222029, and haplotype AAGA of CYP2R1 rs7936142-rs12794714-rs2060793-rs16930609 were genetic risk factors toward a lower 25(OH)D concentration. In contrast, haplotype TGGGCCC of DHCR7/NADSYN1 rs1790349-rs7122671-rs1790329-rs11606033-rs2276360-rs1629220-rs2282618 were genetic protective factors. The results suggest that the GC, CYP2R1, and DHCR7/NADSYN1 genes might contribute to variability in the serum 25(OH)D levels in a healthy Chinese population in Shanghai. These markers could be used as tools in Mendelian randomization analyses of vitamin D, and they could potentially be drug targets in the Chinese population in Shanghai.

The association between serum 25-hydroxyvitamin d concentration and consumption frequencies of vitamin d food sources in korean adolescents

The objectives of this study were to investigate the status of vitamin D in Korean adolescents and to determine the association between serum 25-hydroxyvitamin D (25(OH)D) concentration and consumption frequencies of vitamin D food sources by season (June to November and December to May). The subjects were 1,579 adolescents aged 12-18 years participating in the 2008-2009 Korean National Health and Nutrition Examination Survey (KNHANES). Consumption frequencies of vitamin D food sources were estimated by using a qualitative food frequency questionnaire (FFQ). Thirteen food items were selected as vitamin D food sources including beef, egg, mackerel, tuna, yellow corvine, pollack, anchovy, mushroom, milk, yoghurt, ice cream, all fish and dairy products from the FFQ based on previous research. The data was analyzed using proc survey procedures. The deficiency (5.25-12 ng/mL), inadequacy (12-20 ng/mL) and sufficiency (> 20 ng/mL) proportions of serum 25(OH)D from June to November and December to May were 9.9%, 51.4%, 38.7%, and 39.4%, 51.4%, 9.2%, respectively. Mean serum 25(OH)D concentration was positively related to the consumption frequencies of mackerel, anchovy, all fish and milk. These results suggest high proportion (> 61%) of Korean adolescents were vitamin D deficiency or inadequacy, and serum 25(OH)D was associated with the consumption of vitamin D food sources including fish and milk.

Vitamin D deficiency, interleukin 17, and vascular function in rheumatoid arthritis

OBJECTIVE

Vitamin D deficiency is associated with increased cardiovascular (CV) disease risk in the general population. We examined the association between vitamin D deficiency and CV risk in rheumatoid arthritis (RA).

METHODS

We measured large artery compliance by pulse wave velocity and microvascular function by the reactive hyperemia index in patients with stable RA (n = 87). We quantified CV risk factors, serum 25-hydroxyvitamin D [25(OH)D], and interleukin 17 (IL-17), and RA disease activity by Disease Activity Score of 28 joints. We used linear regression to test associations between serum 25(OH)D and CV risk factors.

RESULTS

The mean serum 25(OH)D level in the cohort was 27.1 ± SD 13.6 ng/ml. Fifty-nine patients (68%) were vitamin D-insufficient (25(OH)D < 30 ng/ml; mean 20.2 ± 5.9 ng/ml) and of these, 25 (29%) were vitamin D-deficient (25(OH)D < 20 ng/ml; mean 14.4 ± 3.4 ng/ml). In the whole cohort and the vitamin D-insufficient group, serum 25(OH)D was inversely associated with IL-17 (log IL-17; β = -0.83, p = 0.04; β = -0.63, p = 0.004, respectively) by univariate analysis, which persisted after adjustment for season, and in multivariate analysis after adjustment for confounders (log IL-17; β = -0.74, p = 0.04; β = -0.53, p = 0.02). In vitamin D-deficient patients, serum 25(OH)D was positively associated with microvascular function by univariate and multivariate analysis after adjustment for confounders (β = 2.1, p = 0.04; β = 2.7, p = 0.04).

CONCLUSION

Vitamin D deficiency in RA may affect Th17 responses and microvascular function. Maintaining normal serum vitamin D levels may protect against IL-17-mediated inflammation and vascular dysfunction in RA.

Prevalence of vitamin D insufficiency in survivors of childhood cancer

BACKGROUND

Data on 25-hydroxyvitamin D (25-OH D) status among survivors of childhood cancer are limited. Our aim was to determine the prevalence of and risk factors for 25-OH D insufficiency in a large, diverse population of cancer survivors being followed in a childhood cancer survivor clinic.

PROCEDURE

Retrospective chart review in survivors seen for routine long-term follow-up, who underwent routine screening blood studies including 25-OH D levels. Vitamin D insufficiency was defined as 25-OH D <20 ng/ml.

RESULTS

Four hundred eighty-four subjects (234 males) were evaluable for this analysis. Median age at 25-OH D testing was 12.3 years (2.05-36.4) and median age at cancer diagnosis was 3.9 years (0-18). Diagnoses included brain tumors (23.6%), neuroblastoma (21%), and leukemia (17.6%). Mean 25-OH D level was 25.2 ng/ml (SD = 10.37); 29% of subjects were 25-OH D insufficient. In univariate analysis, race, pubertal status, and age at cancer diagnosis were associated with 25-OH D insufficiency (P < 0.05). In multivariate analysis, a model including race and pubertal status provided a good fit for the data.

CONCLUSIONS

The prevalence of 25-OH D insufficiency in these cancer survivors was high but similar to what has been described in the general population. No cancer specific variables were associated with 25-OH D insufficiency. Since cancer survivors are at a higher risk for subsequent malignancies, cardiovascular disease, and low bone mineral density, all of which may be affected by 25-OH D levels, interventions to improve 25-OH D status in this vulnerable population are needed.

Prevalence of classic signs and symptoms of rickets and vitamin D deficiency in Mongolian children and women

In order to assess the current nutrition status of Mongolian population, including rickets and vitamin D deficiency of children and women, the Fourth National Nutrition Cross-Sectional Survey was conducted in 21 aimags (provinces) of 4 economic regions of the country and capital city Ulaanbaatar in 2010. Children of age under five years, and non-pregnant women of reproductive age were used as subjects for assessing rickets and vitamin D deficiency. A total of 400 households were randomly selected from each of 4 economic regions and Ulaanbaatar city. Clinical examinations were performed on 706 children of age under five years. Interviews were used to assess vitamin D supplement use. The serum level of 25-hydroxyvitamin D was measured in 524 children aged 6-59 months and in 867 women of reproductive age. This survey found that 21.8% of children had vitamin D deficiency, 20.6% had low vitamin D reserve, and 30.0% of women had vitamin D deficiency and 22.2% had low vitamin D reserve. The prevalence of vitamin D deficiency in children (35.0%, 95% CI, 24.7-47.0) and women (54.9%, 95% CI 45.5-64.0) in the Eastern Region was (35.0%, 95% CI, 24.7-47.0) significantly higher than in the Western, Khangai, Central Regions, and Ulaanbaatar. Further it was found that 27.4% of children under-two years had received vitamin D supplementation. The proportion of children, who did not receive vitamin D supplementation had a higher prevalence of vitamin D deficiency than that of the children of the Eastern Region. None of the women who were involved in this survey had received vitamin D supplementation; 10.2% of them had delivered in the past 12 months, and 22.5% were breastfeeding. The prevalence of classic signs and symptoms of rickets were commonly reported among children of age under five, and skeletal abnormalities more commonly reported in children aged 12-47 months. In conclusion, there is a high prevalence of classic signs and symptoms of rickets in children of age under five years. Vitamin D supplementation in adequate doses for the prevention and treatment of rickets in children is insufficient. Thus, a trial survey is needed to assess the safe and effective doses of vitamin D supplementation necessary for the maintenance of normal serum 25-hydroxyvitamin D concentrations in Mongolian children, and women. In addition, a vitamin D food fortification program is required. This article is part of a Special Issue entitled 'Vitamin D Workshop'.

Prevalence and predictors of vitamin D deficiency in healthy adults

OBJECTIVE

Vitamin D deficiency is highly prevalent in high-risk patient populations, but the prevalence among otherwise healthy adults is less well-defined. The goal of this study was to determine the prevalence and predictors of low 25-hydroxyvitamin D [25(OH)D] levels in healthy younger adults.

METHODS

This was a cross-sectional study of 634 healthy volunteers aged 18-50 years performed between January, 2006 and May, 2008. We measured serum 25(OH)D and parathyroid hormone and recorded demographic variables including age, sex, race, and use of multivitamin supplements.

RESULTS

Thirty-nine percent of subjects had 25(OH)D ≤ 20 ng/mL and 64% had 25(OH)D ≤ 30 ng/mL. Predictors of lower 25(OH)D levels included male sex, black or Asian race, and lack of multivitamin use (P<0.001 for each predictor). Seasonal variation in 25(OH)D levels was present in the overall cohort but was not observed in multivitamin users. Lower 25(OH)D levels were associated with increased risk of elevated parathyroid hormone. Regression models predicted 25(OH)D levels ≤ 20 or ≤ 30 ng/mL with areas under the receiver operating characteristic curves of 0.76 and 0.80, respectively.

CONCLUSION

Low 25(OH)D levels are prevalent in healthy adults and may confer risk of skeletal disease. Black and Asian adults are at increased risk of deficiency and multivitamin use appears partially protective. Our models predicting low 25(OH)D levels may guide decision-making regarding whom to screen for vitamin D deficiency.

Vitamin D status in cord blood and newborns: ethnic differences

BACKGROUND

A deficiency in vitamin D (25OHD) is common throughout the world in both adults and children, being related to skin pigmentation, sun exposure, dietary intake and obesity. Limited data are available for the neonatal age. The aim of the study is to understand the differences in 25OHD levels with respect to skin colour and ethnicity in newborns.

METHODS

We randomly enrolled 62 neonates, born at term and appropriate for gestational age. Thirty two were born from Italian mothers with fair skin (FS) and 30 from non-Caucasian mothers (North African, African, Asian and Latin American): 10 with light olive/light brown (LOB) and 20 with medium brown/black skin (MBB). Vitamin D was measured in the cord blood at birth and in neonatal serum during metabolic screening.

RESULTS

25OHD levels were (mean ± SD) 21.4 ± 11 ng/ml in cord blood and 14.9 ± 7 ng/ml in serum after birth. 25OHD values were higher in cord blood (p < 0.01) and neonatal serum (p < 0.001) in subjects supplemented with Vitamin D. Newborn FS showed higher vitamin D levels in cord blood when compared to LOB and MBB (p < 0.01), and higher levels in neonatal serum when compared to LOB (p < 0.01). In cord blood, 25OHD levels were higher in Italian newborns than in North African (p < 0.004) and African (p < 0.01). In neonatal serum, 25OHD levels were higher in Italian infants only when compared with North African infants (p < 0.03).

CONCLUSIONS

The present study shows a high prevalence of vitamin D insufficiency and deficiency in newborns with significant differences observed to be due to ethnicity, skin colour and maternal supplementation during the pregnancy.

Race-ethnicity is a strong correlate of circulating fat-soluble nutrient concentrations in a representative sample of the U.S. population

Sociodemographic and lifestyle factors exert important influences on nutritional status; however, information on their association with biomarkers of fat-soluble nutrients is limited, particularly in a representative sample of adults. Serum or plasma concentrations of vitamin A, vitamin E, carotenes, xanthophylls, 25-hydroxyvitamin D [25(OH)D], SFAs, MUFAs, PUFAs, and total fatty acids (tFAs) were measured in adults (aged ≥ 20 y) during all or part of NHANES 2003-2006. Simple and multiple linear regression models were used to assess 5 sociodemographic variables (age, sex, race-ethnicity, education, and income) and 5 lifestyle behaviors (smoking, alcohol consumption, BMI, physical activity, and supplement use) and their relation to biomarker concentrations. Adjustment for total serum cholesterol and lipid-altering drug use was added to the full regression model. Adjustment for latitude and season was added to the full model for 25(OH)D. Based on simple linear regression, race-ethnicity, BMI, and supplement use were significantly related to all fat-soluble biomarkers. Sociodemographic variables as a group explained 5-17% of biomarker variability, whereas together, sociodemographic and lifestyle variables explained 22-23% [25(OH)D, vitamin E, xanthophylls], 17% (vitamin A), 15% (MUFAs), 10-11% (SFAs, carotenes, tFAs), and 6% (PUFAs) of biomarker variability. Although lipid adjustment explained additional variability for all biomarkers except for 25(OH)D, it appeared to be largely independent of sociodemographic and lifestyle variables. After adjusting for sociodemographic, lifestyle, and lipid-related variables, major differences in biomarkers were associated with race-ethnicity (from -44 to 57%), smoking (up to -25%), supplement use (up to 21%), and BMI (up to -15%). Latitude and season attenuated some race-ethnicity differences. Of the sociodemographic and lifestyle variables examined, with or without lipid adjustment, most fat-soluble nutrient biomarkers were significantly associated with race-ethnicity.

Vitamin, mineral, and drug absorption following bariatric surgery

The prevalence of obesity continues to rise throughout the world. Increasingly, bariatric surgery is used for those with morbid obesity as a pivotal approach to achieve weight loss. Along with substantial weight loss, malabsorption of essential vitamins, minerals, and drugs also occurs. Therefore, more than ever, a better understanding of the physiology and mechanisms by which these deficiencies occur is essential. We review the normal physiology of vitamin, mineral, and drug absorption. This is followed by a description of currently performed bariatric surgeries in the United States. A detailed review of specific nutrient and mineral deficiency states is presented, based on the most significant studies published in the last two decades. Of note, screening and supplementation recommendations have been included. Drug absorption data after these procedures is presented and discussed. Studies were identified by searching the Cochrane Registry and MEDLINE using relevant search terms, as well as through review of the reference section of included manuscripts.

CONCLUSIONS

Bariatric surgery can be effectively used to achieve sustainable weight-loss in morbidly obese patients. It simultaneously brings forth important functional consequences on nutrient deficiencies and drug absorption that clinician's must be aware of. Further prospective, randomized research on specific procedures and deficiencies is required.

A randomized clinical trial of vitamin D supplementation in healthy adolescents

PURPOSE

The most safe and effective dose of vitamin D supplementation for healthy adolescents is currently unknown. The aim of this study was to compare the efficacy of 200 IU versus 1,000 IU of daily vitamin D3 for supplementation in healthy adolescents with baseline vitamin D sufficiency.

METHODS

We conducted a double-blind, randomized clinical trial. Fifty-six subjects, ages 11-19 years, with baseline vitamin D sufficiency received 1,000 IU or 200 IU of daily vitamin D3 for 11 weeks. Compliance was assessed using MEMS6 Trackcaps and pill counts.

RESULTS

Fifty-three subjects completed the clinical trial. Subjects in the two treatment arms were similar in terms of age, race, gender, body mass index, and dietary calcium and vitamin D intake. Serum 25(OH)D level in the 200 IU treatment arm was 28.1 ± 6.2 ng/mL at baseline (mean ± SD) and 28.9 ± 7.0 ng/mL at follow-up. In the 1,000 IU treatment arm, 25(OH)D levels were 29.0 ± 7.3 and 30.1 ± 6.6 at baseline and follow-up, respectively. Mean change in 25(OH)D level did not differ significantly between treatment arms (p = .87), nor did mean change in parathyroid hormone, calcium, phosphate, bone turnover markers, fasting glucose, or fasting insulin.

CONCLUSIONS

In healthy adolescents with baseline vitamin D sufficiency, supplementation with vitamin D3 doses of 200 and 1,000 IU for 11 weeks did not increase serum 25(OH)D levels, with no significant difference observed between treatment arms.

Predicted vitamin D status and incidence of tooth loss and periodontitis

OBJECTIVE

Vitamin D insufficiency is highly prevalent, with particular subgroups at greater risk (e.g. the elderly and those with darker skin). Vitamin D insufficiency may partly explain US racial/ethnic disparities in the prevalence of periodontitis and tooth loss. We evaluated the association between a predictor score of plasma 25-hydroxyvitamin D (25(OH)D) and incidence of periodontitis and tooth loss.

DESIGN

Detailed biennial questionnaires were collected on medical history, lifestyle practices and incident periodontitis and tooth loss. The predictor score was derived from variables known to influence circulating concentrations of plasma 25(OH)D and validated against plasma concentrations among a sub-sample. Multivariable Cox proportional-hazards models with time-varying covariates estimated the association between the predicted 25(OH)D score and time until first tooth loss.

SUBJECTS

A total of 42,730 participants of the Health Professionals Follow-Up Study aged 40-75 years at baseline were followed from 1986 to 2006.

SETTING

USA, representing all fifty states and the District of Columbia.

RESULTS

We observed 13,581 incident tooth loss events from 539,335 person-years. There was a dose-dependent significant inverse association across quintiles of the predicted 25(OH)D score and incidence of tooth loss. In multivariable analyses, the highest quintile of the updated predicted 25(OH)D score compared with the lowest was associated with a 20% lower incidence of tooth loss (hazard ratio = 0.80, 95 % CI 0.76, 0.85; P value for trend <0.001); UV-B was also independently associated. Results for the predicted 25(OH)D score and periodontitis were similar.

CONCLUSIONS

These results are suggestive of an association between predictors of vitamin D and lower incidence of tooth loss and periodontitis.

A possible correlation between vitamin D deficiency and loss of smell: 2 case reports

OBJECTIVE

The purpose of this report is to present 2 cases of diminished olfaction that improved with increasing serum levels of vitamin D3.

CLINICAL FEATURES

Both patients were under the care of medical and chiropractic physicians for various complaints. A 47-year-old hyposmic woman was diagnosed with vitamin D deficiency who incidentally noticed a progressive return of her sense of smell while taking vitamin D supplements as prescribed by her medical doctor. A 34-year-old anosmic woman noticed a direct relationship with her ability to smell and vitamin D3 supplementation.

INTERVENTION AND OUTCOME

Treatment for the first patient consisted of vitamin D supplementation of 10 000 IU a day. Her serum D3 levels increased substantially over a period of 8 months, at which time she reported a marked improvement in her sense of smell. The second patient was prescribed 50 000 IU of vitamin D a week; and she reported an increased ability to smell, although only the strongest of odors.

CONCLUSION

A link between hypovitaminosis D and a diminished sense of smell was noted in these 2 individuals.

Prevalence of hypovitaminosis D among children with upper extremity fractures

BACKGROUND

Recent publications show a high rate of hypovitaminosis D among children in general as well as among children with fractures. 25-hydroxyvitamin D levels were analyzed from hospital records to determine the prevalence of hypovitaminosis D, with the goal of using that information in fracture management and nutritional counseling.

METHODS

We retrospectively reviewed the records of 213 children with upper extremity fractures that were treated during a 14-month period. For 181 of those patients, the 25-hydroxyvitamin D level was measured at the time of emergency department presentation or at the first clinic appointment within 2 weeks after the initial presentation. The following information was collected from the charts: fracture mechanism (high or low energy), age, sex, race, and body mass index. Vitamin D levels were categorized as normal (≥ 32 ng/mL), insufficient (20 to 32 ng/mL), or deficient (< 20 ng/mL). The levels were analyzed with respect to fracture pattern and race.

RESULTS

Of the 181 patients, 24% had deficient vitamin D levels, 41% had insufficient levels, and 35% had normal levels. There was no significant correlation with vitamin D level and mechanism of injury. African American children were more likely to have insufficient or deficient levels of vitamin D.

CONCLUSIONS

Hypovitaminosis D is common among children with upper extremity fractures. Further investigation is warranted on the use of the 25-hydroxyvitamin D level as a screening tool to predict risk of fracture and to design proper nutritional programs for children with fractures.

LEVEL OF EVIDENCE

Retrospective chart review; Level III evidence.

Role of vitamin d in cardiometabolic diseases

Vitamin D deficiency is a highly prevalent condition. Low vitamin D levels have long been associated with bone diseases, such as rickets in children and osteomalacia and osteoporosis in adults. However, it has become apparent in recent years that adequate vitamin D levels are also important for optimal functioning of many organs and tissues throughout the body, including the cardiovascular system. Evolving data indicate that vitamin D deficiency is associated with an increased risk of cardiovascular disease (CVD). Studies have shown that low vitamin D levels are associated with hypertension, diabetes, metabolic syndrome, left ventricular hypertrophy, and chronic vascular inflammation, all of which are risk factors for CVD. This paper reviews the definition and pathophysiology of vitamin D deficiency, clinical evidence linking vitamin D and CVD risk, diabetes and its complications, and metabolic syndrome.

Seasonal changes in vitamin D status among Danish adolescent girls and elderly women: the influence of sun exposure and vitamin D intake

BACKGROUND/OBJECTIVES

To determine seasonal variation in vitamin D status in healthy Caucasian adolescent girls and elderly community-dwelling women living in Denmark, and to quantify the impact of sun exposure and intake on the seasonal changes in vitamin D status.

SUBJECTS/METHODS

A 1-year longitudinal observational study of 54 girls (11-13 years) and 52 women (70-75 years). The participants were examined three times (winter-summer-winter). Serum 25-hydroxyvitamin D (S-25OHD) concentration and vitamin D intake were measured at each visit. Sun exposure was measured during summer.

RESULTS

S-25OHD concentrations (winter, summer, winter) were median (25, 75 percentiles) 23.4 (16.5, 36.4), 60.3 (42.7, 67.7), 29.5 (22.2, 40.4) and 47.2 (27.3, 61.1), 67.3 (35.1, 79.2), 50.5 (32.7, 65.5)nmol/l for girls and women, respectively. The usual sun habits were determinant (P=0.002) for change in vitamin D status from winter to summer. Vitamin D intake from supplements (P<0.0001) and diet (P=0.002) were determinants for change in vitamin D status from summer to winter. Winter vitamin D status of 50 nmol/l is achievable when vitamin D status the previous summer was ≈ 100 nmol/l. If summer vitamin D status is only ≈ 60 nmol/l, vitamin D status the following winter would be ≈ 28 nmol/l.

CONCLUSIONS

Low vitamin D status among adolescent girls and elderly women during two consecutive winter seasons, improved vitamin D status during the summer and better vitamin D status in women than in girls was found. The estimations show that a summer S-25OHD concentration ≈ 100 nmol/l is needed to achieve a concentration of ≈ 50 nmol/l the following winter.

Age-related differences in asthma outcomes in the United States, 1988-2006

BACKGROUND

Relatively little is known about the effect of age on asthma outcomes in adults, particularly at a national level.

OBJECTIVE

To investigate age-related differences in asthma outcomes in a nationally representative, longitudinal study.

METHODS

We analyzed data from the Third National Health and Nutrition Examination Survey (1988-1994) with linked mortality files through 2006. Adults with physician-diagnosed asthma were identified and were divided into 2 age groups: younger adults (17-54 years of age) and older adults (55 years or older). The outcome measures were both cross-sectional (health care use, comorbidity, and lung function) and longitudinal (all-cause mortality).

RESULTS

There were an estimated 9,566,000 adults with current asthma. Of these, 73% were younger adults and 27% older adults. Compared with younger adults, older adults had more hospitalizations in the past year, more comorbidities, and poorer lung function (eg, lower forced expiratory volume in 1 second) (P < .05 for all). During a median follow-up of 15 years, significant baseline predictors of higher all-cause mortality included older age (≥55 vs <55 years old: adjusted hazard ratio [HR], 6.77; 95% confidence interval [CI], 3.15-14.54), poor health status (fair and poor vs excellent health status: adjusted HR, 10.07; 95% CI, 3.75-27.01), and vitamin D deficiency (vitamin D level <30 vs ≥50 nmol/L: adjusted HR, 2.19; 95% CI, 1.05-4.58), whereas Mexican American ethnicity (adjusted HR, 0.31; 95% CI, 0.14-0.65) was associated with lower mortality. Controlling for age, asthma was not associated with increased all-cause mortality (adjusted HR, 1.28; 95% CI, 0.99-1.65).

CONCLUSION

Older adults with asthma have a substantial burden of morbidity and increased mortality. The ethnic differences in asthma mortality and the vitamin D-mortality link merit further investigation.

Lifestyle modification in colorectal cancer patients: an integrative oncology approach

Colorectal cancer (CRC) is predominantly a disease of economically developed countries, with many lifestyle-related risk factors proposed that contribute to a higher incidence. These risk factors include obesity, especially visceral fat, lack of physical activity, high consumption of red and processed meat, alcohol and a low intake of dietary fiber. Many population-based studies suggest that a combination of these lifestyle-related risk factors not only increases the incidence of CRC, but also contributes to an increased risk of CRC recurrence after the initial diagnosis. In this article we have reviewed various scientific studies that link lifestyle risk factors with CRC and we propose lifestyle modification as an adjunct intervention to surgery and chemotherapy in patients with early stage and locally advanced CRC.

Vitamin D and bone health in childhood and adolescence

Vitamin D plays a key role in bone metabolism. The link between vitamin D deficiency and rickets is well understood. However, subclinical vitamin D deficiency may also be detrimental to bone health in childhood. Its effects on bone mineralization have the potential to result in lower peak bone mass being attained, which could in turn contribute to increased fracture risk in both childhood and older adult life. As vitamin D deficiency is common globally, any detrimental effects of vitamin D deficiency on bone health are likely to have substantial public health implications. This review describes the current literature relevant to vitamin D and bone health in childhood and adolescence, with a particular emphasis on evaluating the emerging evidence for the impact of subclinical vitamin D deficiency on bone health and the effectiveness of vitamin D supplementation. The evidence suggests that subclinical vitamin D deficiency does affect bone acquisition, potentially beginning in utero and extending into adolescence. However, the effectiveness of vitamin D supplementation for improving bone health in situations of subclinical deficiency remains unclear, particularly in early life where there are few trials with bone density outcomes. The available evidence suggests that benefits are likely to be greatest in or even restricted to children with serum 25-hydroxyvitamin D levels at least below 50 nmol/L and possibly even lower than this. Trials of sufficient duration in deficient pregnant mothers, infants, and children are urgently required to address critical evidence gaps.

The world pandemic of vitamin D deficiency could possibly be explained by cellular inflammatory response activity induced by the renin-angiotensin system

This review attempts to show that there may be a relationship between inflammatory processes induced by chronic overstimulation of the renin-angiotensin system (RAS) and the worldwide deficiency of vitamin D (VitD) and that both disorders are probably associated with environmental factors. Low VitD levels represent a risk factor for several apparently different diseases, such as infectious, autoimmune, neurodegenerative, and cardiovascular diseases, as well as diabetes, osteoporosis, and cancer. Moreover, VitD insufficiency seems to predispose to hypertension, metabolic syndrome, left ventricular hypertrophy, heart failure, and chronic vascular inflammation. On the other hand, inappropriate stimulation of the RAS has also been associated with the pathogenesis of hypertension, heart attack, stroke, and hypertrophy of the left ventricle and vascular smooth muscle cells. Because VitD receptors (VDRs) and RAS receptors are almost distributed in the same tissues, a possible link between VitD and the RAS is even more plausible. Furthermore, from an evolutionary point of view, both systems were developed simultaneously, actively participating in the regulation of inflammatory and immunological mechanisms. Changes in RAS activity and activation of the VDR seem to be inversely related; thus any changes in one of these systems would have a completely opposite effect on the other, making it possible to speculate that the two systems could have a feedback relationship. In fact, the pandemic of VitD deficiency could be the other face of increased RAS activity, which probably causes lower activity or lower levels of VitD. Finally, from a therapeutic point of view, the combination of RAS blockade and VDR stimulation appears to be more effective than either RAS blockade or VDR stimulation individually.

Serum 25-hydroxyvitamin D and breast cancer in the military: a case-control study utilizing pre-diagnostic serum

PURPOSE

The objective of this study was to ascertain whether a relationship exists between pre-diagnostic serum levels of 25-hydroxyvitamin D (25(OH)D) and risk of breast cancer in young women.

METHODS

About 600 incident cases of breast cancer were matched to 600 controls as part of a nested case-control study that utilized pre-diagnostic sera. Logistic regression was used to assess the relationship between serum 25(OH)D concentration and breast cancer risk, controlling for race and age.

RESULTS

According to the conditional logistic regression for all subjects, odds ratios for breast cancer by quintile of serum 25(OH)D from lowest to highest were 1.2, 1.0, 0.9, 1.1, and 1.0 (reference) (p trend = 0.72). After multivariate regression for subjects whose blood had been collected within 90 days preceding diagnosis, odds ratios for breast cancer by quintile of serum 25(OH)D from lowest to highest were 3.3, 1.9, 1.7, 2.6, and 1.0 (reference) (p trend = 0.09).

CONCLUSIONS

An inverse association between serum 25(OH)D concentration and risk of breast cancer was not present in the principal analysis, although an inverse association was present in a small subgroup analysis of subjects whose blood had been collected within 90 days preceding diagnosis. Further prospective studies of 25(OH)D and breast cancer risk are needed.

Racial disparities in allergic outcomes in African Americans emerge as early as age 2 years

BACKGROUND

Racial disparities in allergic disease outcomes have been reported with African Americans suffering disproportionately compared to White individuals.

OBJECTIVE

To examine whether or not racial disparities are present as early as age 2 years in a racially diverse birth cohort in the Detroit metropolitan area.

METHODS

All children who were participants in a birth cohort study in the Detroit metropolitan area were invited for a standardized physician exam with skin prick testing and parental interview at age 2 years. Physicians made inquiries regarding wheezing and allergy symptoms and inspected for and graded any atopic dermatitis (AD). Skin testing was performed for Alternaria, cat, cockroach, dog, Dermatophagoides farinae (Der F), Short Ragweed, Timothy grass, egg, milk and peanut. Specific IgE was measured for these same allergens and total IgE was determined.

RESULTS

African American children (n = 466) were more likely than White children (n = 223) to have experienced any of the outcomes examined: at least 1 positive skin prick test from the panel of 10 allergens (21.7% vs. 11.0%, P = 0.001); at least one specific IgE ≥ 0.35 IU/mL (out of a panel of 10 allergens) (54.0% vs. 42.9%, P = 0.02); had AD (27.0% vs. 13.5%, Chi-square P < 0.001); and to ever have wheezed (44.9% vs. 36.0%, P = 0.03). African American children also tended to have higher total IgE (geometric means 23.4 IU/mL (95%CI 20.8, 27.6) vs. 16.7 IU/mL (95%CI 13.6, 20.6 IU/mL), Wilcoxon Rank Sum P = 0.004). With the exception of wheezing, the associations did not vary after adjusting for common social economic status variables (e.g. household income), environmental variables (endotoxin; dog, cat and cockroach allergen in house dust) or variables that differed between the racial groups (e.g. breastfeeding). After adjustment, the wheeze difference was ameliorated.

CONCLUSIONS

With disparities emerging as early as age 2 years, investigations into sources of the disparities should include the prenatal period and early life.

Time course of 25(OH)D3 vitamin D3 as well as PTH (parathyroid hormone) during fracture healing of patients with normal and low bone mineral density (BMD)

BACKGROUND

Until now the exact biochemical processes during healing of metaphyseal fractures of healthy and osteoporotic bone remain unclear. Especially the physiological time courses of 25(OH)D(3) (Vitamin D) as well as PTH (Parathyroid Hormone) the most important modulators of calcium and bone homeostasis are not yet examined sufficiently. The purpose of this study was to focus on the time course of these parameters during fracture healing.

METHODS

In the presented study, we analyse the time course of 25(OH)D3 and PTH during fracture healing of low BMD level fractures versus normal BMD level fractures in a matched pair analysis. Between March 2007 and February 2009 30 patients older than 50 years of age who had suffered a metaphyseal fracture of the proximal humerus, the distal radius or the proximal femur were included in our study. Osteoporosis was verified by DEXA measuring. The time courses of 25(OH)D(3) and PTH were examined over an eight week period. Friedmann test, the Wilcoxon signed rank test and the Mann-Withney U test were used as post-hoc tests. A p-value ≤ 0.05 was considered significant.

RESULTS

Serum levels of 25(OH)D(3) showed no differences in both groups. In the first phase of fracture healing PTH levels in the low BMD level group remained below those of the normal BMD group in absolute figures. Over all no significant differences between low BMD level bone and normal BMD level bone could be detected in our study.

CONCLUSIONS

The time course of 25(OH)D(3) and PTH during fracture healing of patients with normal and low bone mineral density were examined for the first time in humans in this setting and allowing molecular biological insights into fracture healing in metaphyseal bones on a molecural level. There were no significant differences between patients with normal and low BMD levels. Hence further studies will be necessary to obtain more detailed insight into fracture healing in order to provide reliable decision criteria for therapy and the monitoring of fracture healing.

Time course of 25(OH)D3 vitamin D3 as well as PTH (parathyroid hormone) during fracture healing of patients with normal and low bone mineral density (BMD)

BACKGROUND

Until now the exact biochemical processes during healing of metaphyseal fractures of healthy and osteoporotic bone remain unclear. Especially the physiological time courses of 25(OH)D(3) (Vitamin D) as well as PTH (Parathyroid Hormone) the most important modulators of calcium and bone homeostasis are not yet examined sufficiently. The purpose of this study was to focus on the time course of these parameters during fracture healing.

METHODS

In the presented study, we analyse the time course of 25(OH)D3 and PTH during fracture healing of low BMD level fractures versus normal BMD level fractures in a matched pair analysis. Between March 2007 and February 2009 30 patients older than 50 years of age who had suffered a metaphyseal fracture of the proximal humerus, the distal radius or the proximal femur were included in our study. Osteoporosis was verified by DEXA measuring. The time courses of 25(OH)D(3) and PTH were examined over an eight week period. Friedmann test, the Wilcoxon signed rank test and the Mann-Withney U test were used as post-hoc tests. A p-value ≤ 0.05 was considered significant.

RESULTS

Serum levels of 25(OH)D(3) showed no differences in both groups. In the first phase of fracture healing PTH levels in the low BMD level group remained below those of the normal BMD group in absolute figures. Over all no significant differences between low BMD level bone and normal BMD level bone could be detected in our study.

CONCLUSIONS

The time course of 25(OH)D(3) and PTH during fracture healing of patients with normal and low bone mineral density were examined for the first time in humans in this setting and allowing molecular biological insights into fracture healing in metaphyseal bones on a molecural level. There were no significant differences between patients with normal and low BMD levels. Hence further studies will be necessary to obtain more detailed insight into fracture healing in order to provide reliable decision criteria for therapy and the monitoring of fracture healing.

Prevalence and seasonal variation of hypovitaminosis D and its relationship to bone metabolism in healthy Hungarian men over 50 years of age: the HunMen Study

This study reports a high prevalence of hypovitaminosis D and low bone mineral density (BMD) in a healthy Hungarian male cohort over 50 years of age. Men with 25-hydroxyvitamin D levels of <75 nmol/L had a significantly higher 10-year hip and major osteoporotic fracture probability using the country-specific fracture risk assessment (FRAX) algorithm.

INTRODUCTION

The aim of this study is to characterize the prevalence and seasonal variation of hypovitaminosis D and its relationship to bone metabolism in healthy Hungarian men over 50 years of age.

METHODS

We determined levels of 25-hydroxyvitamin D (25-OH-D), PTH, osteocalcin (OC), C-terminal telopeptides of type-I collagen (CTX-I), procollagen type 1 amino-terminal propeptide (PINP), BMD at L1-L4 (LS) and femur neck (FN), daily dietary calcium intake, and the 10-year probability of hip fracture and a major osteoporotic fracture using the country-specific FRAX algorithm in 206 randomly selected ambulatory men.

RESULTS

The mean (range) age of the volunteers was 60 (51-81) years. The prevalence of hypovitaminosis D (25-OH-D, <75 nmol/L) was 52.9%. The prevalence of low (T-score < -1.0) BMD at the FN and LS was 45% and 35.4%, respectively. The mean (range) FRAX hip fracture and FRAX major osteoporotic fracture was 0.8% (0-9.4%) and 3.8% (1.7-16%), respectively. On comparing the vitamin D sufficient to the insufficient group, there was a statistically significant difference between the FRAX hip fracture and FRAX major osteoporotic fracture indexes. There was significant seasonal variation in the vitamin D levels; the lowest levels were measured in winter and the highest in summer.

CONCLUSIONS

A high prevalence of hypovitaminosis D and low BMD were observed in the studied Hungarian male population. This is the first study reporting higher 10-year hip and major osteoporotic fracture probability using the country-specific FRAX algorithm in individuals with hypovitaminosis D.

25-hydroxyvitamin D insufficiency is associated with impaired renal endothelial function and both are improved with rosuvastatin treatment

BACKGROUND

Vitamin D deficiency is nowadays considered as a potential cardiovascular and renal risk factor. We tested the hypotheses that vitamin D deficiency impairs the endothelial function of renal vasculature and whether vitamin D levels and endothelial function can be improved by the treatment with statins.

METHODS

In a double-blind, randomized study of 31 hypercholesterolemic patients with vitamin D insufficiency (<30 ng/ml) were randomly assigned to rosuvastatin (10 mg/d) and placebo for 6 weeks. Basal nitric oxide (NO) activity of the renal vasculature was assessed both before and after the blockade of NO synthases with systemic infusion of N(G)-monomethyl-L-arginine (L-NMMA). In parallel, 25(OH)D was measured.

RESULTS

Multiple regression analysis revealed that at baseline 25(OH)D is an independent determinant of basal NO activity as assessed by the decrease in RPF, in response to L-NMMA (β = -0.446, r = 0.015). Compared to placebo treatment, rosuvastatin increased 25(OH)D levels (21.6 ± 4.0 vs. 24.1 ± 8.1 ng/ml, p = 0.039). Basal NO activity was significantly more increased after 6-week therapy with rosuvastatin than with placebo (-94.8 ± 70 vs. -68.2 ± 32 ml/min, p = 0.044), indicating increased basal NOS activity after 6 weeks of rosuvastatin treatment. Basal NO activity in the placebo phase was correlated inversely with 25(OH)D (r = -0.385; p = 0.027).

CONCLUSIONS

Thus, vitamin D insufficiency is associated with impaired endothelial function in the renal vasculature and both were beneficially influenced by the treatment with rosuvastatin.

Which vitamin D oral supplement is best for postmenopausal women?

Next to a healthy calcium and protein rich diet and exercise, vitamin D supplementation is a key pillar of osteoporosis prevention among postmenopausal women. This article reviews the recent recommendations on vitamin D by the IOF (2010), the Institute of Medicine (2010), and the US Endocrine Society (2011), including the evidence to support these recommendations for fracture and fall prevention. The recent recommendations agree that supplementation should be performed with vitamin D3 or vitamin D2, and that a minimal serum 25-hydroxyvitamin D threshold of 50 nmol/l (20 ng/ml)should be achieved to overcome vitamin D deficiency. In contrast to the Institute of Medicine, the IOF and the US Endocrine Society recommend vitamin D also for the prevention of falls, and state that for fracture prevention a higher serum 25-hydroxyvitamin D threshold of 75 nmol/l (30 ng/ml) should be targeted.

Prospective study of serum 25-hydroxyvitamin D concentration and mortality in a Chinese population

Prospective epidemiologic data on the association between vitamin D and mortality are limited, particularly in Asian populations. Among subjects in Linxian, China, the authors aimed to test whether baseline serum 25-hydroxyvitamin D (25(OH)D) concentrations in a prospective cohort were associated with all-cause mortality and cause-specific mortality rates over 24 years of follow-up (1986-2010). Serum 25(OH)D concentrations were measured in 1,101 subjects using an immunoassay. Hazard ratios and 95% confidence intervals were calculated using Cox regression models that were adjusted for age, sex, tobacco smoking, alcohol drinking, and hypertension. The 25th, 50th, and 75th percentile concentrations of 25(OH)D were 19.6, 31.9, and 48.4 nmol/L, respectively. During follow-up, 793 subjects died, including 279 who died of cerebrovascular accident, 217 who died of cancer, and 200 cardiovascular disease deaths. All-cause mortality was not associated with 25(OH)D concentrations using continuous models (for every 15 nmol/L, hazard ratio = 1.01, 95% confidence interval: 0.97, 1.05) or quartile models (fourth vs. first quartiles, hazard ratio = 1.06, 95% confidence interval: 0.87, 1.30; P for trend = 0.731). The authors also found no association with the cause-specific mortality outcomes. Results were similar for men and women. This study showed that prediagnostic serum 25(OH)D concentrations were not associated with all-cause or cause-specific mortality rates in this Chinese population who had low levels of vitamin D.