Vitamin D intakes of children differ by race/ethnicity, sex, age, and income in the United States, 2007 to 2010

Diet-Related Health Inequalities in High-Income Countries: A Scoping Review of Observational Studies

Diet-related health inequalities are a persistent public health challenge in high-income countries, disproportionately affecting socially and economically disadvantaged populations. This study aims to map the existing evidence on diet-related health inequalities in high-income countries through a scoping review of observational studies, identifying populations most affected and key dietary outcomes across social determinants of health. We conducted a systematic search of MEDLINE, Web of Science, Scopus, and Embase for observational studies published between January 2011 and March 2021. Eligible studies assessed diet-related health outcomes stratified by ≥1 Place of Residence, Race/Ethnicity, Occupation, Gender/Sex, Religion, Education, Socioeconomic Status, and Social Capital (PROGRESS)-Plus determinant. We followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews guidelines and registered the review with International Prospective Register of Systematic Reviews (CRD42021234567). Data were charted and analyzed thematically according to PROGRESS categories. A total of 163 studies were included. Most studies focused on education, socioeconomic status, and place of residence, whereas fewer addressed gender identity, sexual orientation, or disability. Common dietary indicators included fruit and vegetable intake, dietary patterns, and food group consumption. Evidence consistently showed that lower education and income levels were associated with poorer dietary outcomes. Notably, certain population groups (for example, ethnic minorities, rural residents, and individuals with low education or income) experienced cumulative disadvantages. The scoping review highlights persistent and intersecting diet-related health inequalities in high-income countries. It underscores the need for standardized indicators and intersectional approaches in monitoring, research, and policy making.

The Influence of Vitamin D Levels on Dental Caries: A Retrospective Study of the United States Population

(1) Background: This study examines vitamin D's impact on dental caries to inform prevention strategies, given its critical role in bone and calcium regulation, vital for dental health. (2) Methods: Data from 18,683 participants of the National Health and Nutrition Examination Survey (NHANES) 2011-2016 were analyzed. NHANES collects U.S. population data through interviews, physical exams, and tests, including vitamin D levels and dental health assessed using both the decayed, missing, and filled teeth (DMFT) index and the presence of untreated dental caries. Vitamin D levels were measured according to serum 25(OH)D concentrations, and the analyses adjusted for confounders such as body mass index (BMI) and socioeconomic status (SES) using Chi-square, Mann-Whitney U, Kruskal-Wallis tests, as well as logistic and Poisson regression. (3) Results: This study found a mean DMFT score of 7.36 and a 33.2% prevalence of untreated dental caries. A higher caries prevalence was correlated with a lower SES (p < 0.001), the male gender (p < 0.001), and a higher BMI (p < 0.001). Severe vitamin D deficiency (<25 nmol/L) doubled the risk of dental caries, with odds ratios of 2.261 and 1.953 after adjusting for demographic factors and BMI. (4) Conclusions: Our study confirms a significant relationship between low vitamin D levels and an increased risk of dental caries nationwide, even after accounting for sociodemographic factors, emphasizing the importance of maintaining sufficient vitamin D levels for preventing caries.

A review of dairy food intake for improving health among black children and adolescents in the US

Adequate nutrition during childhood and adolescence is crucial for proper neurological, musculoskeletal, immunological, and cardiometabolic health and development. Yet, disparities among socially underserved racial/ethnic groups in the United States (US) provide significant challenges to achieving adequate nutrition during these years of rapid growth and maturation. For example, Black children and adolescents are at greater risk for having food insecurity, lower-quality diets, obesity, and numerous associated health challenges that result from these disparities compared to their White peers. A growing body of evidence indicates that improving diet quality is critical for improving childhood and adolescent health and well-being, and that the diverse nutritional profile and bioactive compounds found within dairy foods may play multiple roles in promoting proper growth and development during these life stages. Therefore, to support overall health and development among Black youth, greater education and implementation efforts are needed to help this population meet the national dietary recommendations of 2.5 to 3 servings of dairy foods per day. Continuing to fall short of these recommendations puts Black children and adolescents at risk of multiple nutrient inadequacies and health disparities that can have lifelong impacts on disease development, mental health, and quality of life. This review presents the state of knowledge on health disparities and modifiable nutritional strategies involving milk and dairy foods to support the growth and maturation of children and adolescents, with a special focus on Black youth in the US.

The role of dairy food intake for improving health among black Americans across the life continuum: A summary of the evidence

Decades of health data show major health disparities occurring at every life stage between Black and White Americans. These disparities include greater mortality rates among Black mothers and their offspring, higher levels of malnutrition and obesity among Black children and adolescents, and a higher burden of chronic disease and lower life expectancy for Black adults. Although nutrition is only one of many factors that influence human health and well-being across the life continuum, a growing body of research continues to demonstrate that consuming a healthy dietary pattern is one of the most dominant factors associated with increased longevity, improved mental health, improved immunity, and decreased risk for obesity and chronic disease. Unfortunately, large percentages of Black Americans tend to consume inadequate amounts of several essential nutrients such as vitamin A, vitamin D, calcium, and magnesium; and simultaneously consume excessive amounts of fast foods and sugar-sweetened beverages to a greater degree than other racial/ethnic groups. Therefore, strategies that can help improve dietary patterns for Black Americans could make up a major public health opportunity for reducing nutrition-related diseases and health disparities across the life course. A key intervention strategy to improve diet quality among Black Americans is to focus on increasing the intake of nutrient-rich dairy foods, which are significantly underconsumed by most Black Americans. Compared to other food group, dairy foods are some of the most accessible and affordable sources of essential nutrients like vitamin A, D, and B12, calcium, magnesium, potassium, selenium, and zinc in the food supply, as well as being some of the primary sources of several health-promoting bioactive compounds, including polar lipids, bioactive proteins and peptides, oligosaccharides, and live and active cultures in fermented products. Given the complex relationships that many Black Americans have with dairy foods, due to issues with lactose intolerance, and/or negative perceptions about the health effects of dairy foods, there is still a need to examine the role that dairy foods play in the health and well-being of Black Americans of all ages and life stages. Therefore, the National Medical Association and its partners have produced multiple reports on the value of including adequate dairy in the diet of Black Americans. This present summary paper and its associated series of evidence reviews provide an examination of an immense amount of research focused on dairy intake and health outcomes, with an emphasis on evidence-based strategies for improving the health of Black Americans. Overall, the findings and conclusions from this body of research continue to indicate that higher dairy intake is associated with reduced risk for many of the most commonly occurring deficiencies and diseases impacting each life stage, and that Black Americans would receive significantly greater health benefits by increasing their daily dairy intake levels to meet the national recommendations than they would from continuing to fall short of these recommendations. However, these recommendations must be considered with appropriate context and nuance as the intake of different dairy products can have different impacts on health outcomes. For instance, vitamin D fortified dairy products and fermented dairy products like yogurt - which are low in lactose and rich in live and active cultures - tend to show the greatest benefits for improved health. Importantly, there are significant limitations to these research findings for Black Americans, especially as they relate to reproductive and child health, since most of the research on dairy intake and health has failed to include adequate representation of Black populations or to sufficiently address the role of dairy intake during the most vulnerable life stages, such as pregancy, lactation, fetal development, early childhood, and older age. This population and these life stages require considerably more research and policy attention if health equity is ever to be achieved for Black Americans. Sharing and applying the learnings from this summary paper and its associated series of evidence reviews will help inform and empower nutrition and health practitioners to provide more evidence-based dietary recommendations for improving the health and well-being of Black Americans across the life course.

Dietary vitamin D intake and sun exposure are not associated with type 1 diabetic schoolchildren and adolescents: A first report in Algeria

BACKGROUND: A large number of children and adolescents worldwide suffer from physiological vitamin D (VD) deficiency, which has been associated with sun exposure and, consequently, the risk of developing various autoimmune diseases, including type 1 diabetes (T1D). However, the association of the disease with VD intake and sun exposure has yet to be explored. MATERIALS AND METHODS: We conducted a food frequency questionnaire and a 24-hour food recall survey, using “Ciqual table 2016” in 335 type 1 diabetic and age- and gender-matched healthy Algerian school children and adolescents from sunny Saharan and relatively less sunny Northern regions, aged between 5 and 19 years. RESULTS: Both dietary VD intake and VD levels were similar in T1D patients when comparing northern and southern regions (for both comparisons, p > 0.05). Neither sun exposure nor VD intake was associated with the disease (respectively, relative risk [RR] = 1.050, p = 0.680; RR = 1.082, p = 1.000. For Cochran and Mantel-Haenszel analysis; RR = 0.841, p = 0.862). VD intake showed a significant difference between diabetics and non-diabetics in the sunny region (p = 0.022). Additionally, significant differences were found between normal and T1D schoolboys (p = 0.038), and when comparing the two groups according to the dry areas (p = 0.016). Moreover, in contrast to circulating VD levels, which were lower in T1D patients than in healthy controls, those of VD intake were significantly higher (p < 0.05), especially in male patients and in those with balanced diet, low protein or carbohydrate consumption, specific food intolerances, and regular meals (p < 0.05), as well as in patients with a moderate or low consumption of cooked meals or steamed foods (p < 0.01). Conversely, VD intake was markedly lower in type 1 diabetics than in controls for dry and sunny areas, including the region of Adrar, as well as for consumption of low-fat foods and eggs (p < 0.05 for all comparisons). Nevertheless, the relative risk of sun exposure and dietary vitamin D intake according to the World Health Organization (WHO) standard did not show a significant association with T1D (common Mantel-Haenszel estimation, RR = 0.841, 95% CI 0.118–5.973, p > 0.05). CONCLUSIONS: T1D does not appear to be associated with VD intake and sun exposure in the Algerian Sahara region. Therefore, the consumption of VD in T1D patients in the Algerian Sahara would suspect that its association with the disease would be related to its synthesis alteration.

Low socioeconomic status predicts vitamin D status in a cross-section of Irish children

Vitamin D is essential for bone and muscle health with adequate status in childhood crucial for normal skeletal development. We aimed to investigate vitamin D status in a convenience sample (n = 1226) of Irish children (aged 1-17 years) who had serum 25-hydroxyvitamin D (25(OH)D) tested by request of their GP at a Dublin Hospital between 2014 and 2020. We examined predictors including age, sex, season and socioeconomic status (SES). Vitamin D deficiency (<30 nmol/l) was prevalent affecting 23 % and was more common in disadvantaged areas (34 %) and in those aged >12 v. ≤12 years (24 % v. 16 %, P = 0⋅033). The greatest predictor was SES (disadvantaged v. affluent, OR 2⋅18, CI 1⋅34, 3⋅53, P = 0⋅002), followed by female sex (OR 1⋅57, CI 1⋅15, 2⋅14, P = 0⋅005) and winter season (October to February, OR 1⋅40, CI 1⋅07, 1⋅84, P = 0⋅015). A quarter of our sample of children were deficient, rising to one-third in those in disadvantaged areas. Females and those aged over 12 years had a higher prevalence of deficiency. Public health strategies to improve vitamin D status in Irish children, including systematic food fortification may need to be considered to address this issue.

Dietary vitamin D intake and sun exposure are not associated with type 1 diabetic schoolchildren and adolescents: a first report in Algerian Sahara.. [DOI: 10.1101/2022.07.17.22276883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Background

A great number of children and adolescents worldwide suffer from physiological Vitamin D (VD) deficiency, which has been associated to the sun exposure and, consequently, to the risk of the development of various autoimmune diseases, including type 1 diabetes (T1D). However, the association of the disease with VD intake and sun exposure have yet to be explored.

Materials and methods

We conducted a food frequency questionnaire and 24-hour recall food survey, using “Ciqual table 2016” in 335 type 1 diabetic and age- and gender-matched healthy Algerian school children and teenager pupils from sunny Saharan and relatively less sunny Northern regions, aged between 5 and 19 years old.

Results

Both dietary VD intake and VD levels were similar in T1D patients when comparing between North and South regions (for the two comparisons, p > 0.05). Neither sun exposure, nor VD intake was associated with the disease (respectively, relative risk [RR] = 1.050, p = 0.680; RR = 1.082, p = 1.000. For Cochran and Mantel-Haenszel analysis; RR = 0.841, p = 0.862). VD intake showed a significant difference between diabetics and non-diabetics in sunny region (p = 0.022). Additionally, significant differences were highlighted between normal and T1D schoolboys (p = 0.038), and when comparing the two groups according to the dry areas (p = 0.016). Moreover, in contrast with the levels of circulating VD, which is decreased in T1D patients than in healthy controls, those of VD intake was significantly higher (p < 0.05), especially in male patients and in those with balanced diet, poor protein or carbohydrate consumption, a particular food intolerance, and a regular meal (p < 0.05), as well as in patients with a moderate or low consumption of cooked meals or steamed food (p < 0.01). Conversely, VD intake was markedly lower in type 1 diabetics than in controls regarding dry sunny region, including Adrar area, as well as in low fatty foods and eggs consumption (p < 0.05 for all comparisons). Nevertheless, relative risk of sun exposure and dietary vitamin D intake according to the WHO standard showed no significant association with T1D (common Mantel-Haenszel estimation, RR = 0.841, 95% CI 0.118-5.973, p > 0.05).

Conclusions

T1D seems to be not associated with VD intake and sun exposure in the Algerian Sahara region. Therefore, the consumption of VD in T1D patients from the Algerian Sahara would suspect that its association with the disease would be related to its synthesis alteration.

Adjunctive vitamin D therapy in various diseases in children: a scenario according to standard guideline

BACKGROUND

Adherence to standard guidelines is imperative when question comes to disease management. The present study aimed to evaluate the administration of adjunctive vitamin D therapy in various diseases, its adherence to standard guideline and the effect of socioeconomic status on the consumption of vitamin D in children.

METHODS

Cross sectional observational study was conducted among 400 ambulatory pediatric patients at Children's Hospital, Pakistan Institute of Medical Sciences Islamabad, from November 2017 to June 2018. Data were collected by a self-designed structured questionnaire from the patient's medical chart. Adjunctive vitamin D therapy adherence was evaluated by the U. S endocrinology clinical practice guideline of vitamin D deficiency. The association between socioeconomic status and consumption of vitamin D was examined by chi-square. Alpha value (p ≤ 0.005) was considered statistically significant. Statistical analysis was done by SPSS version 25.

RESULTS

In 400 patients, 9 diseases and 21 comorbid conditions were identified, in which adjunctive vitamin D therapy was prescribed. Adherence to vitamin D testing in high-risk vitamin D deficiency diseases as; seizures (3.8%), bone deformities (13.3%), steroid-resistant nephrotic syndrome (0.0%), cerebral palsy (5.9%) and meningitis (14.3%). Adherence to prescribed vitamin D dose was in (41.3%) patients in various diseases. Significant association (p < 0.05) was found between socioeconomic status and consumption of vitamin D in children and mothers.

CONCLUSIONS

It was found that adjunctive vitamin D was being prescribed in various diseases and comorbidities. Overall poor adherence to the standard guideline was observed in disease management in children. Low socioeconomic status affects vitamin D supplementation consumption in children.

Urinary Phytoestrogen Metabolites Positively Correlate with Serum 25(OH)D Level Based on National Health and Nutrition Examination Survey 2009-2010

Studies showed that vitamin D (25-hydroxyvitamin D) level in the human blood circulation could be affected by exogenous estrogen exposure. This study aims to explore the relationships between urinary phytoestrogens metabolites and serum total 25(OH)D in general population, urinary phytoestrogens metabolites (daidzein, enterodiol, enterolactone, equol, genistein and o-desmethylangolensin). Totally 2,609 adults ≥6 y old from the 2009-2010 National Health and Nutrition Examination Surveys (NHANES) were recruited into the cross-sectional analyses and information including demographic, socioeconomic, examinations and laboratory test were collected. All analyses were performed using Stata13.0, one-way analysis of variance and multivariable regression were utilised according to data characteristics, respectively. It showed that age, race, education level, body mass index (BMI), and sampling season had significant effects on serum 25(OH)D level (all p<0.001). In the whole population, urinary enterodiol and equol were significantly positively associated with serum total 25(OH)D level (β=0.86, 95%CI=0.08-1.65, p<0.05; β=1.68, 95%CI=0.91-2.45, p<0.001). Equol was also found significantly positively correlated with total 25(OH)D in both female and male separately (β=1.69, 95%CI=0.51-2.87, p<0.05; β=1.66, 95%CI=0.63-2.69, p<0.05). Phytoestrogen concentrations in the urinary and 25(OH)D levels in the serum had proved a positive correlation in our study, which provide theoretical basis and reference for the dietary nutrient intake in the population.

Nutritional problems in childhood and adolescence: a narrative review of identified disparities

To inform programmes and policies that promote health equity, it is essential to monitor the distribution of nutritional problems among young individuals. Common nutritional problems include overall low diet quality, the underconsumption and overconsumption of certain dietary components, unhealthy meal and snack patterns, problematic feeding practices and disordered eating. The objective of the present narrative review was to summarise recent evidence of disparities among US children (2-19 years) according to age, sex, socio-economic status, ethnicity/race and rural-urban location. Searches in PubMed® and MEDLINE® were completed to identify peer-reviewed research studies published between January 2009 and January 2019. Findings from the ninety-nine reviewed studies indicate adolescent females, young individuals from lower socio-economic households and individuals who identify as non-Hispanic Black race are particularly vulnerable populations for whom targeted strategies should be developed to address evidence of increased risk with regards to multiple aspects of nutritional wellbeing. Limitations of the existing evidence relate to the accuracy of self-reported dietary data; the need for consistent definitions of disordered eating; the focus on individual dietary components v. patterns; the complexities of categorising socio-economic status, ethnicity/race, and rural and urban areas; and the cross-sectional, observational nature of most research designs. There is an urgent need for research to address these limitations and fill a large gap in evidence on rural-urban differences in nutritional problems. It will further be important for future studies to build greater understanding of how nutritional problems cluster among population groups.

Serum 25-hydroxyvitamin D is associated with obesity and metabolic parameters in US children

OBJECTIVE

To explore the relationships of serum 25-hydroxyvitamin D (25(OH)D) with obesity and metabolic parameters in US children.

DESIGN

Cross-sectional analysis. We evaluated the associations between serum 25(OH)D and multiple measurements of adiposity, serum lipid concentrations, fasting glucose and insulin resistance in children aged 6-18 years with adjustments for multiple covariates.

SETTING

The National Health and Nutrition Examination Survey, 2001-2006.

PARTICIPANTS

A nationally representative sample of 6311 children and adolescents aged 6-18 years.

RESULTS

Among US children and adolescents, the prevalence of vitamin D deficiency has been especially high in older children, girls and the non-Hispanic Black population. Higher odds of obesity were found at a 25(OH)D concentration of <30 nmol/l (deficiency) than at >50 nmol/l under both criteria for obesity in children (OR = 3·27, Ptrend ≤ 0.001). Moreover, increased odds of having abnormal HDL-cholesterol (OR = 1·71, Ptrend ≤ 0.001) and impaired insulin resistance (OR = 4·15, Ptrend ≤ 0·001) were found for children deficient in 25(OH)D compared with those with normal 25(OH)D concentrations. When the children and adolescents were stratified by gender, we found stronger associations between serum 25(OH)D concentration and both HDL-cholesterol and insulin resistance in girls. No association of 25(OH)D with any other metabolic parameter was found.

CONCLUSIONS

Our results suggest a potential harmful association between low serum 25(OH)D concentration and the risk of obesity among children. However, the underlying mechanisms require further investigation.

Excessive abdominal adiposity and body fat are associated with lower serum vitamin D levels: A population-based study

ABSTRACT Objective To estimate the prevalence of 25-hydroxyvitamin D deficiency and to analyze factors associated with lower serum vitamin levels in Brazilian adults. Methods A cross-sectional, population-based study consisted of 626 adult individuals of both sexes living in the urban area of Viçosa, Minas Gerais. The dependent variable used was the serum level of 25-hydroxyvitamin D and the independent variables were sociodemographic, anthropometric and body composition variables. The associations among the variables were verified using simple and multiple linear regression models, considering alpha lower than 0.05 for the input in the final model. Results The prevalence of 25-hydroxyvitamin D deficiency was 14.4% and the prevalence was 42.0%. Excess abdominal fat was higher in subjects with 25-hydroxyvitamin D sufficiency. The serum level of 25-hydroxyvitamin D was 30.34±9.85ng/ml. Body adiposity was higher in men with vitamin insufficiency. Negative associations were observed between serum 25-hydroxyvitamin D levels and age, educational level, body adiposity (p=0.028) and abdominal adiposity (p=0.023). Conclusion Our results showed that excess body and abdominal adiposity are strong predictors of alterations in the serum vitamin D levels, thus public policies for prevention and treatment in this population are essential.

Contribution of Dietary Supplements to Nutritional Adequacy by Socioeconomic Subgroups in Adults of the United States

Many Americans have inadequate intakes of several nutrients, and the Dietary Guidelines for Americans 2015–2020 identified vitamins A, C, D, and E, in addition to calcium, magnesium, iron, potassium, choline, and fiber as “underconsumed nutrients”. Based on nationally representative data on 10,698 adults from National Health and Nutrition Examination Surveys (NHANES), 2009–2012, assessments were made of socioeconomic differences, based on the Poverty Income Ratio (PIR), in terms of the association of dietary supplement use on nutrient intake and nutrient inadequacies. Compared to food alone, the use of any dietary supplement plus food was associated with significantly (p < 0.01) higher intakes of 15–16 of 19 nutrients examined in all socioeconomic groups; and significantly reduced rates of inadequacy for 10/17 nutrients in the subgroup PIR > 1.85 (not poor), but only 4–5/17 nutrients (calcium and vitamins A, C, D, E) for the poor and nearly poor subgroups (PIR < 1.35 and PIR 1.35 to ≤1.85, respectively). An increased prevalence of intakes above the Tolerable Upper Intake Level (UL) was seen for 3–9/13 nutrients, but all were less than 5% in the PIR subgroups. In conclusion, dietary supplement use was associated with an increased micronutrient intake, decreased inadequacies, and a slight increase in the prevalence of intakes above the UL, with greater benefits seen in the PIR > 1.85 subgroup.

Vitamin D Sufficiency of Canadian Children Did Not Improve Following the 2010 Revision of the Dietary Guidelines That Recommend Higher Intake of Vitamin D: An Analysis of the Canadian Health Measures Survey

In 2010, the dietary guidelines for vitamin D for Canadians and Americans aged 1-70 years were revised upward. It is unknown whether the vitamin D status of Canadian children improved after 2010. We compared the prevalence of vitamin D sufficiency (25-hydroxy vitamin D (25(OH)D) concentration of ≥50 nmol/L), 25(OH)D concentration and the frequency of consuming vitamin D-rich foods among children aged 6-18 years-old using data from the nationally representative 2007/2009 and 2012/2013 Canadian Health Measures Surveys. Associations of sociodemographic, anthropometric, seasonal, and regional variables with achieving vitamin D sufficiency, 25(OH)D concentration, and consumption of vitamin D-rich foods were assessed using multiple logistic and linear regression models. 79% and 68% of children in 2007/2009 and 2012/2013 respectively, were vitamin D sufficient. The main dietary source of vitamin D was milk. Between 2007/2009 and 2012/2013, the frequency of milk and fish consumption declined, but egg and red meat consumption was unchanged. Age, income, weight status, season and ethnicity were associated with 25(OH)D concentration and vitamin D sufficiency. Vitamin D status declined after the upward revision of dietary guidelines for vitamin D, consequently, dietary intake was inadequate to meet sufficiency. Public health initiatives to promote vitamin D-rich foods and supplementation for Canadian children are needed.

25-Hydroxyvitamin D levels of children are inversely related to adiposity assessed by body mass index

Vitamin D deficiency is associated with wide range of pathologies. Some evidences have shown that low vitamin D circulating levels in children and adolescent are related to fat mass and obesity. The objectives of the present study were to characterize vitamin D status in children and adolescents and to determine if serum 25-hydroxyvitamin D (25(OH)D) concentration is related to adiposity assessed by body mass index (BMI). Serum 25(OH)D levels were measured by LIAISON method in 471 children and adolescents (2 to 18 years age) and analyzed according to gender, pubertal period, age, and BMI. An overall prevalence of 25(OH)D insufficiency and deficiency was present in the 67.1%. Lower 25(OH)D levels were found in females (25.56 ± 14.03 vs 29.71 ± 17.10 ng ml^-1; P = 0.004) and pubertal children (25.52 ± 13.97 vs 29.21 ± 16.83 ng ml^-1; P = 0.011). In addition, an inverse relation of BMI and age on 25(OH)D concentrations was observed in children. In conclusion, low vitamin D status was highly prevalent among children and adolescents. Of note, a non-lineal regression model showed that 39.6% of vitamin D levels variability was explained by BMI. These results indicate that adiposity assessed by BMI impacts vitamin D status.

Vitamin D deficiency and sufficiency among Canadian children residing at high latitude following the revision of the RDA of vitamin D intake in 2010

Recently, countries at high latitudes have updated their vitamin D recommendations to ensure adequate intake for the musculoskeletal health of their respective populations. In 2010, the dietary guidelines for vitamin D for Canadians and Americans aged 1–70 years increased from 5 μg/d to 15 μg/d, whereas in 2016 for citizens of the UK aged ≥4 years 10 μg/d is recommended. The vitamin D status of Canadian children following the revised dietary guidelines is unknown. Therefore, this study aimed to assess the prevalence and determinants of vitamin D deficiency and sufficiency among Canadian children. For this study, we assumed serum 25-hydroxy vitamin D (25(OH)D) concentrations <30 nmol/l as ‘deficient’ and ≥50 nmol/l as ‘sufficient’. Data from children aged 3–18 years (n 2270) who participated in the 2012/2013 Canadian Health Measures Survey were analysed. Of all children, 5·6% were vitamin D deficient and 71% were vitamin D sufficient. Children who consumed vitamin D-fortified milk daily (77 %) were more likely to be sufficient than those who consumed it less frequently (OR 2·4; 95% CI 1·7, 3·3). The 9% of children who reported taking vitamin D-containing supplements in the previous month had higher 25(OH)D concentrations (β 5·9 nmol/l; 95% CI 1·3, 12·1 nmol/l) relative to those who did not. Children who were older, obese, of non-white ethnicity and from low-income households were less likely to be vitamin D sufficient. To improve vitamin D status, consumption of vitamin D-rich foods should be promoted, and fortification of more food items or formal recommendations for vitamin D supplementation should be considered.

Elevated systolic blood pressure of children in the United States is associated with low serum 25-hydroxyvitamin D concentrations related to body mass index: National Health and Examination Survey 2007-2010

A negative association between serum 25-hydroxyvitamn D (25[OH]D) concentrations and blood pressure has been found in adults; whether a similar relationship exists in children remains unclear. We hypothesized that serum 25(OH)D concentrations of children would negatively correlate with blood pressure. Using a nationally representative sample of children aged 8 to 18years from the National Health and Nutrition Examination Survey 2007-2010 (n=2908), we compared serum 25(OH)D levels with diastolic and systolic blood pressure by vitamin D nutritional status categories. A high percentage of children were either vitamin D deficient (28.8%) or vitamin D insufficient (48.8%). Prehypertension was defined as blood pressure as ≥90th to <95th percentile and hypertension as ≥95th percentile by age, height, and sex national blood pressure percentile norms for children. Vitamin D-deficient children aged 8 to 13years had higher systolic blood pressure (104.8±0.7mm Hg) than did vitamin D-sufficient children (102.3±0.6mmHg; P<.05). Controlling for age, sex, race/ethnicity, and income, systolic blood pressure was inversely associated with serum 25(OH)D concentrations (P<.03), but not when also controlling for body mass index (P=.63). A higher percentage of vitamin D-deficient and vitamin D-insufficient children (1.7%) vs vitamin D-sufficient children (0.6%) had prehypertension or hypertension. In conclusion, the association of low serum 25(OH)D concentrations with elevated systolic blood pressure in children is likely related to body weight and markers of adiposity.

Parental Encouragement of Healthy Lifestyles for Their Children and Personally Caring about Healthy Lifestyles Is Positively Associated with Children Using Vitamin D Supplements

Supplement users have better vitamin D status, and parenting is key to promoting a child’s healthy behaviours. We examined the association of parental encouragement of and caring about healthy lifestyles with children’s use of vitamin D supplements and multivitamins. A provincially representative sample of grade 5 students (n = 2686; 10–11 years) and their parents across the province of Alberta, Canada, was surveyed in 2014. Students were asked about use of multivitamins and/or vitamin D supplements. Parents were asked whether they cared about and encouraged healthy lifestyles. Mixed effect multiple logistic regression identified the association of parental responses with children’s use of supplements; 29% and 54% of children took vitamin D supplements and multivitamins, respectively. They were more likely to take vitamin D supplements if their parents cared ‘very much’ vs. ‘not at all/a little bit’ about eating healthy foods (OR = 1.43; 95% CI = 1.08, 1.89), cared ‘quite a lot’ (OR = 1.55; 95% CI = 1.17, 2.04) and ‘very much’ (OR = 1.67; 95% CI = 1.26, 2.21) vs. ‘not at all/a little bit’ about physical activity, and encouraged ‘very much’ vs. ‘not at all/a little bit’ their children to eat healthy foods (OR = 1.51; 95% CI = 1.05, 2.17). Children whose parents personally cared for eating healthy foods were more likely to take multivitamins (‘quite a lot’ and ‘very much’ compared to ‘not at all/a little bit’ (OR = 1.60; 95% CI = 1.13, 2.28 and OR = 1.46; 95% CI = 1.04, 2.06, respectively). Education and parental encouragement of healthy lifestyles should be part of the public health initiatives to promote supplementation of vitamin D among children.

The prevalence and determinants of use of vitamin D supplements among children in Alberta, Canada: a cross-sectional study

Background

Limited cutaneous synthesis due to low sun exposure and inadequate dietary intake makes vitamin D supplementation a necessity for many Canadian children. Identification of the factors associated with supplement use is necessary for public health awareness campaigns, but they have not been identified previously. Therefore, the purpose of this study was to assess the prevalence and the determinants of the use of vitamin D supplements among children in the province of Alberta, Canada.

Methods

In 2014, a representative sample of grade five students (10–11 y) in Alberta (n = 2686) was surveyed. Data on dietary intake and use of vitamin D supplements were obtained using a modified Harvard Youth/Adolescent Food Frequency questionnaire. Mixed effect multiple logistic regression was employed to identify the key correlates of supplement use.

Results

Use of vitamin D supplements by children was 29.45 % although only 11.83 % took supplements daily. Children who resided in a metropolitan area (OR = 1.32; 95 % CI:1.06–1.65), were more physically active (2nd tertile: OR = 1.39; 95 % CI:1.09–1.78 and 3rd tertile: OR = 1.70; 95 % CI:1.33–2.16), or whose parents completed college (OR = 1.35; 95 % CI:1.05–1.74) were more likely to take vitamin D supplements. Prevalence of use was highest among those who had a high vitamin D diet and those with under/normal body weight status, although supplement use was not statistically associated with either dietary vitamin D intake or weight status.

Conclusions

A considerable proportion of children did not take vitamin D supplements. Region of residence, physical activity level and parental education were determinants of supplement use, independent of child’s gender, household income, weight status and dietary practices. We suggest prioritizing public health efforts to support strategies to make parents aware of the importance of providing the correct dose of vitamin D supplements for their children to meet dietary recommendations.

Dietary reference intakes for vitamin D based on the revised 2010 dietary guidelines are not being met by children in Alberta, Canada

Canadian children have been shown to be not meeting the revised (2010) dietary recommended intake (DRI) for vitamin D through diet alone. However, no study has evaluated whether diet and supplementation together are supporting Canadian children in meeting the DRIs for vitamin D intake. This study assessed the adequacy of vitamin D intake through diet and supplements among Albertan children and the determinants of meeting dietary guidelines. 2686 grade 5 students aged 10 to 11 years in Alberta, Canada were surveyed. We hypothesized that less than 50% of children would meet the DRI. Vitamin D intake from diet and supplements was assessed using a food frequency questionnaire. The adequacy of vitamin D intake was estimated using the Estimated Average Requirement (EAR) of 400 IU (International Units) and Recommended Dietary Allowance (RDA) of 600 IU. Random effect multiple logistic regression was used to identify correlates of meeting DRIs. Forty five percent of children met the EAR and 22% met the RDA for vitamin D. When vitamin D intake from diet alone was considered, only 16% and 2% met the EAR and RDA, respectively. Parental education, household income and physical activity were positively correlated with meeting DRIs, and students attending metropolitan area schools were more likely to meet the EAR than students attending rural area schools (OR = 1.28; P = .043). The majority of children did not meet the DRI for vitamin D. Health promotion strategies aiming to improve the vitamin D status of Albertan children are necessary given the importance of vitamin D for children's health and development.

First 25-hydroxyvitamin D assay for general chemistry analyzers

25-Hydroxyvitamin D [25(OH)D], the predominant circulating form of vitamin D, is an accurate indicator of the general vitamin D status of an individual. Because vitamin D deficiencies have been linked to several pathologies (including osteoporosis and rickets), accurate monitoring of 25(OH)D levels is becoming increasingly important in clinical settings. Current 25(OH)D assays are either chromatographic or immunoassay-based assays. These assays include HPLC, liquid chromatography-tandem mass spectrometry (LC-MS/MS), enzyme-immunosorbent, immunochemiluminescence, immunofluorescence and radioimmunoassay. All these assays use heterogeneous formats that require phase separation and special instrumentations. In this article, we present an overview of these assays and introduce the first homogeneous assay of 25(OH)D for use on general chemistry analyzers. A special emphasis is put on the unique challenges posed by the 25(OH)D analyte. These challenges include a low detection limit, the dissociation of the analyte from its serum transporter and the inactivation of various binding proteins without phase separation steps.