Marker of vitamin D status in healthy children: Free or total 25-hydroxyvitamin D?

AbstractObjectiveTo investigate seasonal variations of vitamin D status at different latitudes and if these changes are accompanied by corresponding variations in certain health parameters in children living in a broad latitudinal range in Iran.DesignLongitudinal study.SubjectsIn total, 530 apparently healthy children aged 5–18 years were randomly selected from six regions of Iran with a latitudinal gradient from 29°N to 37·5°N. All anthropometric and biochemical assessments were performed twice during a year (summer, winter). High BMI (Z-score >1), low HDL cholesterol (<40 mg/dl, males; <50 mg/dl, females) and high TAG (>150 mg/dl) were considered cardiometabolic risk factors.ResultsSerum 25-hydroxyvitamin D (25(OH)D) showed between-season variation, with significantly higher concentrations (mean (sd)) in summer v. winter (43 (29) v. 27 (18) nmol/l; P<0·001). Change of circulating 25(OH)D between summer and winter was negatively correlated with change of BMI (r=−0·16; P<0·001), TAG (r=−0·09; P=0·04) and total cholesterol (r=−0·10; P=0·02) and directly correlated with change of height-for-age Z-score (r=0·09; P=0·04). Multiple stepwise linear regression analysis (β; 95 % CI) showed that winter serum 25(OH)D (−0·3; −0·4, −0·2; P<0·001), gender (boys v. girls: 9·7; 5·2, 14·1; P<0·001) and latitude (>33°N v. <33°N: 4·5; 0·09, 9·0; P=0·04) were predictors of change of serum 25(OH)D between two seasons.ConclusionsSummertime improvement of vitamin D status was accompanied by certain improved cardiometabolic risk factors, notably serum TAG, total cholesterol and BMI, in children.

Download Full-text

Vitamin D Status in Irish Children and Adolescents

Clinical Pediatrics ◽

10.1177/0009922814541999 ◽

2014 ◽

Vol 53 (14) ◽

pp. 1345-1351 ◽

Cited By ~ 10

Author(s):

Aoife Carroll ◽

Chike Onwuneme ◽

Malachi J. McKenna ◽

Philip D. Mayne ◽

Eleanor J. Molloy ◽

...

Keyword(s):

Vitamin D ◽

Cross Sectional Study ◽

Healthy Children ◽

Vitamin D Status ◽

Formula Milk ◽

Cross Sectional ◽

Hydroxyvitamin D ◽

25 Hydroxyvitamin D ◽

The Mean ◽

Vitamin D Supplements

Background. Vitamin D has important skeletal and extraskeletal roles but those living at northerly latitudes are at risk of suboptimal levels because of reduced sunlight exposure. Aim. To describe the vitamin D status of Irish children and identify factors predictive of vitamin D status. Methods. A prospective cross sectional study was undertaken over a 12 month period. Two hundred and fifty two healthy children attending for minor medical or surgical procedures were recruited. All had 25-hydroxyvitamin D (25OHD), parathyroid hormone and bone profiles measured. Results. The mean (standard deviation) for 25OHD was 51(25) nmol/L (20.4 (10) ng/mL). Forty-five percent had levels >50 nmol/L (20 ng/mL). The following variables were significantly associated with 25OHD levels >50 nmol/L (20 ng/mL): sample drawn in April-September, use of vitamin D supplements, consumption of formula milk, and non-African ethnicity. Conclusion. More than half of the children in this study had 25OHD levels less than 50 nmol/L (20 ng/mL). Vitamin D status was significantly improved by augmented oral vitamin D intake.

Download Full-text

Relationship of Total and Free 25-Hydroxyvitamin D to Biomarkers and Metabolic Indices in Healthy Children

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/clinem/dgz230 ◽

2019 ◽

Vol 105 (4) ◽

pp. e1631-e1640

Author(s):

Christine A Simpson ◽

Jane H Zhang ◽

Dirk Vanderschueren ◽

Lei Fu ◽

Teresita C Pennestri ◽

...

Keyword(s):

Vitamin D ◽

Medical Center ◽

Academic Medical Center ◽

Healthy Children ◽

Model Assessment ◽

Vitamin D Status ◽

Hydroxyvitamin D ◽

Homeostatic Model Assessment ◽

25 Hydroxyvitamin D ◽

Metabolic Indices

Abstract Context Vitamin D status is usually assessed by serum total 25-hydroxyvitamin D (t25-OHD). Whether free 25-hydroxyvitamin D measures better correlate with various clinical outcomes is unclear. Objective To identify correlations between t25-OHD, calculated and direct measures of free 25-OHD, and to identify associations of these measures with other outcomes in children, across the 6 common GC haplotypes. Design Healthy urban-dwelling children underwent measurement of relevant variables. Setting Academic medical center. Participants The study included 203 healthy, urban-dwelling children, aged 6 months to 10 years, predominantly of Hispanic background and representative of all common GC haplotypes. Intervention None. Main Outcome Measures Total and free 25-OHD and 1,25(OH)2D, calcium, phosphate, parathyroid hormone (PTH), glucose, insulin, aldosterone, and renin. Results Mean t25-OHD [26.3 ± 6.7ng/ml; 65.8 ± 16.8nmol/L] were lowest in the GC2 genotype. Mean t1,25(OH)2D [57.6 ± 16.5pg/ml; 143.9 ± 41.3pmol/L], were lowest in GC1f/1f, GC1f/2, and GC2/2 groups. T25-OHD correlated strongly with calculated free 25-OHD (cf25-OHD) (r = 0.89) and moderately with directly measured free 25-OHD (dmf25-OHD) (r = 0.69). Cf25-OHD correlated with dmf25-OHD (r = 0.69) (P < 0.001 for all). t25-OHD inversely correlated with body mass index (BMI) (r=-0.191; P = 0.006), skin reflectometry, and systolic blood pressure. T25-OHD correlated with fasting insulin and the homeostatic model assessment for insulin resistance (HOMA-IR), however significance for these correlations was not evident after adjustment for BMI. PTH inversely correlated with all measures of 25-OHD, but most strongly with t25-OHD. Conclusions Measures of circulating total and free 25-OHD are comparable measures of vitamin D status in heathy children. Correlations are similar with other outcome variables, however t25-OHD remains the strongest correlate of circulating PTH and other variables. These data argue against routine refinement of the t25-OHD measure using currently available assessments of free 25-OHD. Clinical Trial Information Clinicaltrials.gov registration no: NCT01050387 (January 15, 2010).

Download Full-text

Effects of Anticonvulsant Therapy on Vitamin D Status in Children: Prospective Monitoring Study

Journal of Child Neurology ◽

10.2310/7010.2006.00050 ◽

2006 ◽

Vol 21 (3) ◽

pp. 205-210 ◽

Cited By ~ 3

Author(s):

Polyxeni Nicolaidou ◽

Helen Georgouli ◽

Haralambos Kotsalis ◽

Yiannis Matsinos ◽

Anna Papadopoulou ◽

...

Keyword(s):

Vitamin D ◽

Parathyroid Hormone ◽

Sodium Valproate ◽

Hypovitaminosis D ◽

Anticonvulsant Therapy ◽

Control Group ◽

Healthy Children ◽

Vitamin D Status ◽

Hydroxyvitamin D ◽

25 Hydroxyvitamin D

Reports of hypovitaminosis D associated with anticonvulsant drugs in pediatric patients are conflicting. The effects of carbamazepine or sodium valproate on vitamin D status were evaluated prospectively in 51 ambulatory epileptic children who were followed during the first year of the study and in 25 and 6 children during the second and third year, respectively. Serum 25-hydroxyvitamin D, parathyroid hormone, calcium, and phosphorus levels were determined before and every 3 months during anticonvulsant therapy. Our subjects were grouped into four classes (0, 1, 2, and 3 consisted of the patients before and during the first, second, and third years of the treatment, respectively). The control group consisted of 80 healthy children. Comparisons between controls and patients of class 0 for the means for each season of all variables showed no significant differences. A decreasing trend in serum 25-hydroxyvitamin D ( P < .03) and an increasing trend in serum parathyroid hormone ( P < .04) levels were noticed in all seasons from class 0 to class 3. Twenty-five patients (49%) acquired hypovitaminosis D during the study period. The effects of seasonality on serum 25-hydroxyvitamin D, parathyroid hormone, and calcium were noticed in our patients grouped in classes 0, 2 and 3, as well as in controls. Evidence is provided that carbamazepine or sodium valproate can cause hypovitaminosis D in children. ( J Child Neurol 2006; 21:205—209; DOI 10.2310/7010.2006.00050)

Download Full-text

Comparison of Vitamin D and 25-Hydroxyvitamin D Concentrations in Human Breast Milk between 1989 and 2016–2017

Nutrients ◽

10.3390/nu13020573 ◽

2021 ◽

Vol 13 (2) ◽

pp. 573

Author(s):

Naoko Tsugawa ◽

Mayu Nishino ◽

Akiko Kuwabara ◽

Honami Ogasawara ◽

Maya Kamao ◽

...

Keyword(s):

Vitamin D ◽

Breast Milk ◽

Sun Exposure ◽

Stepwise Multiple Regression ◽

Human Breast Milk ◽

Vitamin D Status ◽

Human Breast ◽

Hydroxyvitamin D ◽

Lactating Mothers ◽

25 Hydroxyvitamin D

Background: Breast milk is considered the optimal source of nutrition during infancy. Although the vitamin D concentration in human breast milk is generally considered poor for infants, vitamin D in breast milk is an important source for exclusively breastfed infants. Increases in vitamin D insufficiency and deficiency in lactating mothers may reduce vitamin D concentrations in breast milk. This study aimed to compare vitamin D and 25-hydroxyvitamin D (25OHD) concentrations in breast milk collected in 1989 and 2016–2017 and simultaneously analyze them with liquid chromatography-tandem mass spectrometry (LC-MS/MS); the association between the lifestyle of recent lactating mothers (2016–2017) and vitamin D status in human breast milk was also evaluated. Method: Lactating mothers were recruited from three regions of Japan in 1989 (n = 72) and 2016–2017 (n = 90), and milk from 3–4 months was collected in summer and winter. The samples were strictly sealed and stored at −80℃ until measurement. Breast milk vitamin D and 25OHD concentrations were analyzed by LC-MS/MS. Vitamin D intake, sun exposure, and sunscreen use of the lactating mothers in 2016–2017 were assessed. Results: Both vitamin D and 25OHD concentrations in breast milk were higher in the summer regardless of the survey year. Significantly lower vitamin D and 25OHD concentrations were observed in 2016–2017 compared with 1989 in summer, but no survey year difference was observed in winter. The stepwise multiple regression analyses identified season, daily outdoor activity, and suntan in the last 12 months as independent factors associated with vitamin D3 concentrations. Conclusion: The results suggest that low vitamin D status in recent lactating mothers may have decreased vitamin D and 25OHD concentrations in breast milk compared with the 1980s. These results are helpful for developing public health strategies to improve vitamin D status in lactating mothers and infants.

Download Full-text

COVID-19 Disease Severity and Death in Relation to Vitamin D Status among SARS-CoV-2-Positive UAE Residents

Nutrients ◽

10.3390/nu13051714 ◽

2021 ◽

Vol 13 (5) ◽

pp. 1714

Author(s):

Habiba AlSafar ◽

William B. Grant ◽

Rafiq Hijazi ◽

Maimunah Uddin ◽

Nawal Alkaabi ◽

...

Keyword(s):

Vitamin D ◽

United Arab Emirates ◽

Blood Levels ◽

Vitamin D Status ◽

Hospital Visit ◽

Serum Samples ◽

Hydroxyvitamin D ◽

Increased Risk ◽

Multiethnic Population ◽

25 Hydroxyvitamin D

Insufficient blood levels of the neurohormone vitamin D are associated with increased risk of COVID-19 severity and mortality. Despite the global rollout of vaccinations and promising preliminary results, the focus remains on additional preventive measures to manage COVID-19. Results conflict on vitamin D’s plausible role in preventing and treating COVID-19. We examined the relation between vitamin D status and COVID-19 severity and mortality among the multiethnic population of the United Arab Emirates. Our observational study used data for 522 participants who tested positive for SARS-CoV-2 at one of the main hospitals in Abu Dhabi and Dubai. Only 464 of those patients were included for data analysis. Demographic and clinical data were retrospectively analyzed. Serum samples immediately drawn at the first hospital visit were used to measure serum 25-hydroxyvitamin D [25(OH)D] concentrations through automated electrochemiluminescence. Levels < 12 ng/mL were significantly associated with higher risk of severe COVID-19 infection and of death. Age was the only other independent risk factor, whereas comorbidities and smoking did not contribute to the outcomes upon adjustment. Sex of patients was not an important predictor for severity or death. Our study is the first conducted in the UAE to measure 25(OH)D levels in SARS-CoV-2-positive patients and confirm the association of levels < 12 ng/mL with COVID-19 severity and mortality.

Download Full-text

Vitamin D Status and Seasonal Variation among Danish Children and Adults: A Descriptive Study

Nutrients ◽

10.3390/nu10111801 ◽

2018 ◽

Vol 10 (11) ◽

pp. 1801 ◽

Cited By ~ 20

Author(s):

Louise Hansen ◽

Anne Tjønneland ◽

Brian Køster ◽

Christine Brot ◽

Rikke Andersen ◽

...

Keyword(s):

Vitamin D ◽

Seasonal Variation ◽

Vitamin D Status ◽

Hydroxyvitamin D ◽

Supplement Use ◽

Wide Range ◽

Adults And Children ◽

25 Hydroxyvitamin D ◽

Vitamin D Supplement ◽

Very High

The aim of the present study was to describe vitamin D status and seasonal variation in the general Danish population. In this study, 3092 persons aged 2 to 69 years (2565 adults, 527 children) had blood drawn twice (spring and autumn) between 2012 and 2014. A sub-sample of participants had blood samples taken monthly over a year. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were measured by liquid chromatography mass spectrometry, and information on supplement use was assessed from questionnaires. Seasonal variations in 25(OH)D concentrations were evaluated graphically and descriptively, and status according to age, sex, and supplement use was described. It was found that 86% of both adults and children were vitamin D-sufficient in either spring and or/autumn; however, many had a spring concentration below 50 nmol/L. A wide range of 25(OH)D concentrations were found in spring and autumn, with very low and very high values in both seasons. Among adults, women in general had higher median 25(OH)D concentrations than men. Furthermore, vitamin D supplement use was substantial and affected the median concentrations markedly, more so during spring than autumn. Seasonal variation was thus found to be substantial, and bi-seasonal measurements are vital in order to capture the sizable fluctuations in vitamin D status in this Nordic population.

Download Full-text

Weight and skin colour as predictors of vitamin D status: results of an epidemiological investigation using nationally representative data

Public Health Nutrition ◽

10.1017/s1368980016000173 ◽

2016 ◽

Vol 20 (10) ◽

pp. 1857-1864 ◽

Cited By ~ 5

Author(s):

Sonali Rajan ◽

Tom Weishaar ◽

Bryan Keller

Keyword(s):

Vitamin D ◽

Body Weight ◽

Skin Colour ◽

Vitamin D Status ◽

Epidemiological Investigation ◽

Dietary Recommendations ◽

Hydroxyvitamin D ◽

25 Hydroxyvitamin D ◽

Nationally Representative ◽

The Impact

AbstractObjectiveCurrent US dietary recommendations for vitamin D vary by age. Recent research suggests that body weight and skin colour are also major determinants of vitamin D status. The objective of the present epidemiological investigation was to clarify the role of age as a predictor of vitamin D status, while accounting for body weight and skin colour, among a nationally representative sample.DesignWe calculated the mean serum 25-hydroxyvitamin D levels for the US population by age and weight, as well as by weight and race/ethnicity group. Multiple regression analyses were utilized to evaluate age and weight as predictors of vitamin D status: serum 25-hydroxyvitamin D levels with age alone, age and body weight, and age, body weight and their two-way interaction were modelled for the entire sample and each age subgroup. Graphical data were developed using B-spline non-linear regression.SettingNational Health and Nutrition Examination Survey (31 934 unweighted cases).SubjectsIndividuals aged 1 year and older.ResultsThere were highly significant differences in mean vitamin D status among US residents by weight and skin colour, with those having darker skin colour or higher body weight having worse vitamin D status. Although a significant factor, the impact of age on vitamin D status was notably less than the impact of body weight.ConclusionsVitamin D status varied predominantly by body weight and skin colour. Recommendations by nutritionists for diet and supplementation needs should take this into account if vitamin D-related health disparities are to be meaningfully reduced across the USA.

Download Full-text