Serum 25OHD Levels Research Articles

The prevalence of depressive symptoms in Chinese longevous persons and its correlation with vitamin D status

BackgroundHypovitaminosis D and depressive syndromes are common conditions in old adults. However, little is known about the relationship between vitamin D and depression in exceptional aged people. The objective of this study is to evaluate the relationship between vitamin D levels and depressive symptoms in Chinese longevous persons.MethodsWe used a dataset from a cross-sectional survey of a sample of Chinese longevous people with self-reported age 100 or older, including 175 men and 765 women, was conducted from June 2014 to December 2016 in Hainan Province, China. Data on demographics, lifestyle characteristics and health conditions were collected using a structured questionnaire. Anthropometrics and blood samples were obtained following the standard procedure. Depressive symptoms of the participants were assessed using a shortened version of the Geriatric Depression Scale (GDS-15). Serum vitamin D levels were measured using an automated radioimmunoassay.ResultsThe prevalence of longevous persons with depressive symptoms among the sample was 32.2% (95% confidence interval: 29.7–34.7%). Serum vitamin D levels were lower in participants with depressive symptoms than in those without (20.8 ± 8.7 vs. 23.7 ± 9.7, ng/mL). Vitamin D deficiency was an independent risk factor for depression after controlling for the potential covariates (Odds ratio = 1.47, 95% Confidence interval = 1.08–2.00; p = 0.014). A negative relationship between serum vitamin D levels and depressive symptoms was also detected, and the relationship remained significant after adjusting for a wide range of other covariates. The multivariate adjusted odds ratio of depressive symptoms for the lowest versus highest quartiles of vitamin D levels was 1.73 (95% confidence interval: 1.10–2.72), and the adjusted odds ratio with a 5 ng/mL decrement of serum 25OHD levels was 1.10 (95% confidence interval: 1.01–1.19).ConclusionsThis study showed an inverse association between vitamin D levels and depressive symptoms among Chinese longevous persons. Depressive symptoms should be screened in longevous persons who had vitamin D deficiency. Further studies on vitamin D supplement and prevention along with treatment of depression are needed among very old population.

Serum 25-hydroxyvitamin D3 level may be associated with olfactory dysfunction in de novo Parkinson's disease

The purpose of our study was to investigate the association between olfactory function in Parkinson's disease (PD) and serum vitamin D status. Thirty-nine patients with de novo PD were enrolled in this study. Olfactory function was assessed by an odor identification test, as a part of the KVSS (Korean version of sniffin’ sticks) II test. All patients were also assessed with the NMSS (Non-Motor Symptoms Scale for PD) to check the subjective change in ability to smell. Vitamin D status was determined by measuring the level of serum 25-hydroxyvitamin D3 (25-OHD3). Multiple linear regression tests and correlation analysis were applied to verify the association between serum 25-OHD3 level and patients’ subjective and objective olfactory dysfunction. The serum 25-OHD3 level was independently associated with odor identification score in patients with PD (β = 0.38, p < 0.01). Another statistically significant variable was clinical subtype of PD (Intermediate subtype: β = −0.33, p < 0.05; Akinetic rigid type: β = −0.55, p < 0.01). The serum 25-OHD3 level was also negatively correlated with the score for item number 28 in NMSS (Spearman’s rho = −0.32, p < 0.05). Our results showed that vitamin D status might be an independent factor for olfactory dysfunction in PD. Although the underlying mechanism has not been clearly identified, we postulate that vitamin D plays a role in the pathogenesis of olfactory dysfunction in PD. Further investigation to elucidate the precise relationship of vitamin D to PD is essential.

EVALUATING THE CLINICAL AND PHYSIOLOGICAL EFFECTS OF LONG-TERM ULTRAVIOLET B RADIATION ON RABBITS (ORYCTOLAGUS CUNICULUS)

Vitamin D is an essential hormone in vertebrates. Most animals acquire this hormone through their diet and/or exposure to ultraviolet B (UVB) radiation. The objectives for this research were to evaluate the clinical and physiologic effects of artificial UVB light supplementation on rabbits (Oryctolagus cuniculus) and to evaluate the long-term safety of artificial UVB light supplementation over a 6-month period. Twelve New Zealand white rabbits were randomly assigned to one of two treatment groups: Group A was exposed to 12 hours of artificial UVB radiation daily and Group B received ambient fluorescent light with no UVB supplementation for 12 hours daily. All animals were offered the same diet and housed under the same conditions. Blood samples were collected every 3 weeks over 6 months to measure blood chemistry values, parathyroid hormone, ionized calcium, and serum 25-hydroxyvitamin D3 (25-OHD3) levels. Serial ophthalmologic examinations were performed at the beginning of the study and every 2 months thereafter. At the end of the study the animals were euthanized and necropsied. Mean ± SD serum 25-OHD3 concentrations differed significantly (P = 0.003) between animals provided supplemental UVB radiation (83.12 ± 22.44 nmol/L) and those not provided UVB radiation (39.33 ± 26.07 nmol/L). There were no apparent negative clinical or pathologic side effects noted between the groups. This study found that exposing rabbits to UVB radiation long term significantly increased their circulating serum 25-OHD3 levels, which was sustainable over time.

Correlation between serum 25-hydroxyvitamin D3 and carpal tunnel syndrome in type 2 diabetes

Objective To investigate the relationship between serum 25-OH vitamin D3(25-OHD3)levels and carpal tunnel syndrome(CTS)in type 2 diabetes. Methods Data from 102 patients with type 2 diabetes were collected, and patients were divided into a CTS group(n=29)and a non-CTS group(n=73)according to clinical symptoms, signs, and electrophysiological testing.Fasting venous blood was collected to assay serum 25-OHD3 levels that were compared between the two groups.The correlation between 25-OHD3 and clinical parameters for type 2 diabetes was analyzed. Results The incidence of vitamin D3 deficiency was 65.5%(n=19)in the CTS group and 46.6%(n=34)in the non-CTS group, and the difference was statistically significant(χ2=16.85, P<0.01). Levels of 25-OHD3 were lower in the CTS group(14.13±4.91)μg/L than in the non-CTS group(17.08±3.35)μg/L(t=4.067, P<0.01). Levels of 25-OHD3 were negatively correlated with those of glycosylated hemoglobin(HbA1c)(r=-0.176, P=0.041)and the duration of diabetes(r=-0.29, P=0.01). Conclusions Low 25-OHD3 is a risk factor for carpal tunnel syndrome in type 2 diabetes and is negatively associated with the duration of diabetes and HbA1c in patients with type 2 diabetes. Key words: Diabetes mellitus, type 2; Vitamin D; Carpal tunnel syndrome

Genetic Variants of CYP2R1 Are Key Regulators of Serum Vitamin D Levels and Incidence of Myocardial Infarction in Middle-Aged Egyptians.

Myocardial Infarction (MI) is one of the leading causes of morbidity and mortality in Egypt and worldwide. Vitamin D deficiency has long been linked to incidence of cardiovascular diseases. Several factors were reported to contribute to serum vitamin D level including exposure to sunlight. However, genetic variations in the vitamin D metabolic pathways have also been considered as strong determinants of vitamin D levels. CYP2R1 is the major 25-hydroxylase enzyme that is responsible for the 1st activation step of vitamin D. to investigate the contribution of polymorphisms in CYP2R1 gene to vitamin D deficiency and incidence of MI in Egyptians. The study included 323 subjects; 185 MI patients and 138 healthy controls. Serum 25OHD3, 25OHD2 and total 25OHD levels were measured using LC-MS/MS. SNPs rs2060793 and rs1993116 were determined by polymerase chain reaction - restriction fragment length polymorphism (PCRRFLP) which is considered one of the most commonly used techniques in genotyping. SNP rs10766197 was detected using TaqMan allele discrimination assay. Serum 25OHD3, 25OHD2 and total 25OHD levels were found to be significantly lower in MI patients than controls. The three studied SNPs were associated with significantly different total 25OHD levels and their genotype distributions differed significantly between MI patients and controls where the high risk genotypes were AG/AA for rs2060793, AG/GG for rs1993116 and AG/AA for rs10766197. Additionally, the concurrent presence of high risk genotypes of the three studied SNPs rendered those individuals at extremely higher risk for MI than each individual SNP (OR 14.1, 95% CI (3.1-64.7), p-value = < 0.0001). Genetic variants of CYP2R1 are key determinants of serum 25OHD levels and are highly associated with MI risk.

Screening for vitamin D deficiency in a tropical area: results of a sun exposure questionnaire

BackgroundVitamin D deficiency is pandemic while resources available to measure 25-hydroxyvitamin D (25OHD) are limited. The present study aimed to verify whether sun exposure measured by a structured questionnaire could predict serum 25OHD concentrations in healthy Caucasian individuals living in a tropical area.MethodsA cross-sectional study was carried out in subjects living in the greater São Paulo area, Brazil. Two groups of 50 young (20 to 40 years old) and 50 older (60 to 80 years old) subjects (N = 200) answered a structured questionnaire on sun exposure and had blood samples drawn for serum 25OHD concentration measurement during both summer and winter. Anthropometric data were also recorded. Correlation between the questionnaire variables (duration of sun exposure, amount of exposed skin, total sun exposure score - TSES and other data) and serum 25OHD concentration was evaluated.ResultsMean serum 25OHD concentration was 17.60 ± 7.3 ng/mL with no difference between age groups (p = 0.293). TSES weakly correlated with serum 25OHD levels (r = 0.264; p < 0.001). Separate analyzes by age groups demonstrated that TSES correlated significantly with serum 25OHD concentration only in the older subjects during summer (r = 0.322; p = 0.023). Using linear regression analyses, TSES and body mass index (BMI) were significantly associated with serum 25OHD levels. On the other hand, Receiver operating characteristic (ROC) analysis for TSES showed no significance as a screening tool for vitamin D deficiency (p = 0.172).ConclusionSun exposure questionnaire associated with BMI correlates with serum 25OHD concentration with very low accuracy. The use of the questionnaire does not discriminate between vitamin D sufficient and deficient individuals.

The interrelationship between hepcidin, vitamin D, and anemia in children with acute infectious disease.

Hepcidin is a master regulator of iron metabolism. Recently, it has been shown that vitamin D suppresses hepcidin expression. Our hypothesis was that hepcidin levels inversely correlate with vitamin D levels in anemic children during acute infection. A prospective study was performed on 90 patients (45 females, 45 males, mean age 7.3 ± 5 years) who were admitted to the pediatric ward. Sixty-two patients had infectious disease (32 with coexisting anemia, 30 without anemia), and 28 patients were hospitalized for noninfectious causes. Blood samples for IL-6, hepcidin, iron status parameters, and 25-hydroxyvitamin D (25-OHD) were obtained within 72 h after admission. Serum concentrations of IL-6 and hepcidin were significantly higher and 25-OHD, iron, and transferrin were significantly lower in anemic children with infectious disease compared with controls. Children with a serum 25-OHD level < 20 ng/ml had significantly increased odds of having anemia than those with a level > 20 ng/ml (OR: 6.1, CI: 1.15-32.76). Correlation analyses found positive associations between hepcidin levels and ferritin (R2 = 0.47, P < 0.001) and negative associations between hepcidin and transferrin (R2 = 0.57, P < 0.001). Higher IL-6 and lower 25-OHD levels may lead to higher hepcidin levels and subsequently to hypoferremia and anemia in children with acute infection.

Correlation of admission serum 25-hydroxyvitamin D levels and clinical outcomes in critically ill medical patients

Summary Purpose The aim of this study was to determine the incidence of hypovitaminosis D and the correlation of admission serum 25-hydroxyvitamin D (25-OHD) levels and clinical outcomes in critically ill medical patients. Methods A prospective, observational study was conducted. All critically ill medical patients admitted to the medical ICU were recruited. Blood sampling for serum 25-OHD was taken within 24 h after ICU admission. The levels of 25-OHD were dichotomized into deficiency and sufficiency groups. A serum 25-OHD level Results From 116 cases, the incidence of hypovitaminosis D was 64.66%. The median serum 25-OHD was 15.1 (3.0, 67.2) ng/dL. There was no difference in 28-day mortality between the vitamin D statuses (20% vs. 17.1%, p = 0.70). However, the ICU-acquired infection tended to be higher in the vitamin D deficiency group but this was not statistically significant (25.3% vs. 19.5%, p = 0.07). Other secondary outcomes were comparable between the groups. Vitamin D levels were significantly correlated to the severity of illness of critically ill medical patients (r = −0.258, p = 0.005.) Conclusions The incidence of hypovitaminosis D in critically ill medical patients in our region was high. In this current finding, vitamin D deficiency in critically ill medical patients may not related to 28-day mortality, ICU and hospital mortality, ICU and hospital length of stay, mechanical ventilator days or ICU-acquired infection, but vitamin D levels were significantly correlated to the severity of the illness. However, the larger study is required to confirm this finding. Trial registration The study protocol is retrospectively registered at the Thai Clinical Trial Registry (TCTR) with the identification number TCTR20180211004.

Serum 25-hydroxyvitamin D levels throughout pregnancy: a longitudinal study in healthy and preeclamptic pregnant women

BackgroundWorldwide there is a high prevalence of 25-hydroxyvitamin D (25OHD) deficiency and has been associated with adverse outcomes during pregnancy.ObjectiveThis is a nested, case–control study in a longitudinal cohort to compare the serum 25OHD levels and other biomarkers throughout pregnancy in a group of 20 preeclamptic women and 61 healthy pregnant women. An additional group of 29 healthy non-pregnant women were also studied during the two phases of the menstrual cycle.ResultsMean 25OHD levels in non-pregnant women were 31.9 ng/mL and 34.9 ng/mL during follicular and luteal phase, respectively (P < 0.01). Mean serum 25OHD levels in healthy pregnant women were 26.5, 30.1 and 31.9 ng/mL, at first, second and third trimester, respectively (P < 0.001). The first trimester levels of 25OHD were lower than those of healthy non-pregnant women (P < 0.001), showing a significant recovery at third trimester. In the group of healthy pregnant women, the 25OHD levels were 25.7 ng/mL and 27.2 ng/mL at 3 and 6 months postpartum, respectively; both values were lower than those observed in the non-pregnant women (P < 0.001). In preeclamptic women, 25OHD serum levels were similar to those of healthy pregnant women; nevertheless, they remained almost unchanged throughout pregnancy.ConclusionThere were no significant differences between healthy and preeclamptic pregnant women in terms of 25OHD levels throughout the pregnancy. Serum 25OHD levels in non-pregnant women were higher during luteal phase compared with follicular phase. The 25OHD levels of non-pregnant women tended to be higher than those of pregnant women.

A study of difference in serum 25-hydroxyvitamin D concentrations in patients with angiographically-defined coronary disease and healthy subjects

BackgroundCardiovascular disease (CVD) is one of the most important causes of death in developing countries. The current study evaluates the serum 25-hydroxyvitamin D (25OHD), phosphate and calcium levels in patients with angiographically-defined coronary artery disease (CAD) and healthy subjects in a sample population in northeastern Iran. MethodsThere were 566 subjects aged between 20–80 years out of whom283 subjects with CAD were divided into two study groups based on their angiogram results; those with > 50% stenosis of one or more coronary arteries and those with ≤ 50% stenosis. Serum 25OHD levels and anthropometric parameters were measured for all subjects. ResultsThere were approximately 53% (n = 303) males and 47% (n = 269) females in the population sample. We found that crude serum 25OHD concentrations were significantly higher in both the Angio− (21.6 ± 11.8 ng/ml) and Angio+ (21.3 ± 10.2 ng/ml) groups compared to the control subjects (16.4 ± 9.5 ng/ml) (P < 0.001). ConclusionThe findings show that 25OHD state could be a risk factor for CAD, although this would need to be explored further, taking the potential confounding effects of diet into account in future studies.

Serum 25 Hydroxy Vitamin D Levels in Very Low Birth Weight Infants Receiving Oral Vitamin D Supplementation.

Vitamin D supplementation in preterm infants has been recommended by American Academy of Pediatrics (AAP); however, its efficacy and safety has not been well studied. To study 25-hydroxy vitamin D (25OHD) levels as a marker of vitamin D status of very low birth weight infants while on vitamin D supplementation during neonatal intensive care unit hospitalization. Retrospective study of preterm infants with birth weight <1500 g admitted to our unit from January 2013 to December 2015 who were on oral vitamin D3 400 IU supplementation. Serum 25OHD level were checked at 4, 8, and 12 weeks of age or before discharge and the levels were stratified as deficient <20 ng/mL, insufficient 20 to 29 ng/mL, normal 30 to 60 ng/mL, high 61 to 100 ng/mL and very high >100 ng/mL. A total of 301 infants were enrolled, 186 very low birth weight (VLBW; 1000-1499 g) infants and 115 extremely low birth weight (ELBW; <1000 g) infants. Approximately 80% of both VLBWs and ELBWs had deficient or insufficient 25OHD levels at 4 weeks of age. On oral vitamin D supplementation, VLBW infants increased their 25OHD levels significantly by 8 and 12 weeks of age, whereas ELBW infants lagged behind at 8 weeks and increased their 25OHD levels by 12 weeks of age. Eighty percent of ELBW and VLBW infants have either deficient or insufficient vitamin D status at 4 weeks of age. Vitamin D supplementation helps in improving the vitamin D levels, VLBW infants significantly more than ELBW infants. AAP recommendation appears to be safe; however, if using higher supplement dosing, 25OHD level should be monitored to avoid high and very high vitamin D levels.

Vitamin D levels and parathyroid hormone variations of children living in a subtropical climate: a data mining study

BackgroundVitamin D and intact parathyroid hormone (iPTH) play a crucial role in calcium homeostasis and bone health of children. Serum level of 25-hydroxyvitamin D (25-OHD) is considered to be the most accurate marker for vitamin D status. However, there have only been a few studies, with limited number of subjects, investigating the relationship between 25-OHD and parathyroid hormone (PTH) in children. The aim of this study was to evaluate the seasonal 25-OHD levels and its associations with intact parathyroid hormone (iPTH) in Turkish children at all pediatric ages; and then to define a critical decision threshold level for 25-OHD deficiency in Turkish children.MethodsA retrospective record review of 90,042 children, was performed on serum 25-OHD and for 3525 iPTH levels. They were measured by mass spectrometry method and by electrochemiluminescence immunoassay simultaneously.Results25-OHD levels showed a sinusoidal fluctuation througout the year; being significantly higher in summer and autumn (p < 0,01). 25-OHD levels decreased with respect to age. The significant inverse relationship that was found between iPTH and 25-OHD suggests that the inflection point of serum 25-OHD level for maximal suppression of PTH is at 30 ng/ml.ConclusionAs the rate of vitamin D deficiency decreases in the early years due to vitamin D supplementation, the recommendation should be set due to a clinical threshold level of 30 ng/ml for 25-OHD based on PTH levels in children of our population.

Associations between sun sensitive pigmentary genes and serum prostate specific antigen levels.

BackgroundMelanoma and prostate cancer may share risk factors. This study examined the association between serum PSA levels, which is a risk factor for prostate cancer, and variants in some melanoma-associated pigmentary genes.MethodsWe studied participants, all aged 70+ years, in the Concord Health and Ageing in Men Project who had no history of prostatitis or received treatment for prostate disease (n = 1033). We genotyped variants in MC1R (rs1805007, rs1805008), ASIP (rs4911414, rs1015362), SLC45A2 (rs28777, rs16891982), IRF4 (rs12203592), TYRP1 (rs1408799), TYR (rs1126809, rs1042602), SLC24A2 (rs12896399), and OCA2 (rs7495174). Generalised linear dominant models with Poisson distribution, log link functions and robust variance estimators estimated adjusted percentage differences (%PSA) in mean serum PSA levels (ng/mL) between variant and wildtype (0%PSA = reference) genotypes, adjusting for age, body mass index, serum 25OHD levels and birth regions (Australia or New Zealand (ANZ), Europe or elsewhere).ResultsSerum PSA levels were strongly associated with advancing age and birth regions: mean PSA levels were lower in Europe-born (-29.7%) and elsewhere-born (-11.7%) men than ANZ-born men (reference). Lower %PSA was observed in men with variants in SLC45A2: rs28777 (-19.6;95%CI: -33.5, -2.7), rs16891982 (-17.3;95%CI:-30.4,-1.7) than in wildtype men (reference). There were significant interactions between birth regions and PSA levels in men with variants in MC1R (rs1805007; p-interaction = 0.0001) and ASIP (rs4911414; p-interaction = 0.007). For these genes %PSA was greater in ANZ-born men and lower in Europe- and elsewhere-born men with the variant than it was in wildtype men. In a post hoc analysis, serum testosterone levels were increased in men with MC1R rs1805007 and serum dihydrotestosterone in men with ASIP rs1015362.ConclusionMen with SNPs in SLC45A2, who have less sun sensitive skin, have lower PSA levels. Men with SNPs in MC1R and ASIP, who have more sun sensitive skin, and were born in ANZ, have higher PSA levels. Androgens may modify these apparent associations of pigmentary genes and sun exposure with PSA levels.ImpactPSA levels and possibly prostate cancer risk may vary with sun sensitivity and sun exposure, the effects of which might be modified by androgen levels.

MS Sunshine Study: Sun Exposure But Not Vitamin D Is Associated with Multiple Sclerosis Risk in Blacks and Hispanics.

Multiple sclerosis (MS) incidence and serum 25-hydroxyvitamin D (25OHD) levels vary by race/ethnicity. We examined the consistency of beneficial effects of 25OHD and/or sun exposure for MS risk across multiple racial/ethnic groups. We recruited incident MS cases and controls (blacks 116 cases/131 controls; Hispanics 183/197; whites 247/267) from the membership of Kaiser Permanente Southern California into the MS Sunshine Study to simultaneously examine sun exposure and 25OHD, accounting for genetic ancestry and other factors. Higher lifetime ultraviolet radiation exposure (a rigorous measure of sun exposure) was associated with a lower risk of MS independent of serum 25OHD levels in blacks (adjusted OR = 0.53, 95% CI = 0.31–0.83; p = 0.007) and whites (OR = 0.68, 95% CI = 0.48–0.94; p = 0.020) with a similar magnitude of effect that did not reach statistical significance in Hispanics (OR = 0.66, 95% CI = 0.42–1.04; p = 0.071). Higher serum 25OHD levels were associated with a lower risk of MS only in whites. No association was found in Hispanics or blacks regardless of how 25OHD was modeled. Lifetime sun exposure appears to reduce the risk of MS regardless of race/ethnicity. In contrast, serum 25OHD levels are not associated with MS risk in blacks or Hispanics. Our findings challenge the biological plausibility of vitamin D deficiency as causal for MS and call into question the targeting of specific serum 25OHD levels to achieve health benefits, particularly in blacks and Hispanics.

Circulating 25-hydroxyvitamin D, nasopharyngeal airway metabolome, and bronchiolitis severity.

Low circulating 25-hydroxyvitamin D (25OHD) levels are a risk factor for acute respiratory infection (eg, bronchiolitis) in children. However, little is known about the relation of circulating 25OHD with the many downstream functional molecules in target organs-such as the airway-and with clinical outcomes. In this prospective multicenter study of infants (age <1 year) hospitalized with bronchiolitis, we measured serum 25OHD levels and profiled the metabolome of 144 nasopharyngeal airway samples. Among 254 metabolites identified, we defined a set of 20 metabolites that are related to lower serum 25OHD and higher vitamin D-binding protein levels. Of these metabolites, 9 metabolites were associated with a significantly higher risk of positive pressure ventilation use. These metabolites were glycerophosphocholines esterified with proinflammatory fatty acids (palmitate, arachidonate, linoleate, and stearate), sphingomyelins, alpha-hydroxyisovalerate, 2-hydroxybutyrate, and 3-(4-hydroxyphenyl)lactate (all FDR<0.05). Based on the multicenter data, vitamin D-related airway metabolites were associated with risks of bronchiolitis severity.

Rickets/Osteomalacia. Consensus on Vitamin D Deficiency and Insufficiency in Children.

Vitamin D deficiency is usually manifested as rickets in children. Since vitamin D deficiency/insufficiency is common worldwide, global consensus has been formulated on prevention, diagnosis and treatment of nutritional rickets represented by vitamin D-deficient rickets. This consensus has defined vitamin D insufficiency as the status with serum 25-hydroxyvitamin D(25OHD)level between 12 and 20 ng/mL and vitamin D deficiency as the status with serum 25OHD level below 12 ng/mL. Generally low dietary calcium(Ca)intake coexists with vitamin D deficiency/insufficiency in patients with rickets, and it is important to ensure sufficient Ca intake ensure in the management of nutritional rickets.

Vitamin D and respiratory health in the Busselton Healthy Ageing Study.

The relationship between vitamin D and respiratory disease was examined by cross-sectional analysis of a large community-based sample. Serum 25-hydroxyvitamin D (25OHD) and history of respiratory disease, symptoms (recorded by questionnaire) and spirometry were measured in 5011 adults aged 45-69 years. Adjustments were made for age, sex, season and smoking (Model A), plus body mass index (BMI) and physical activity level (Model B), plus history of chronic diseases (Model C). Mean (SD) age was 58 (SD 6) years with 45% males, 10% current smokers and 12% taking vitamin D supplements. The prevalence of 25OHD level <50 nmol/L was 8.0%. In all the three models, 25OHD <50 nmol/L was significantly associated with asthma (Model C: odds ratio (OR): 1.32; 95% CI: 1.00, 1.73), bronchitis (1.54; 1.17, 2.01), wheeze (1.37; 1.10, 1.71) and chest tightness (1.42; 1.10, 1.83). Participants with vitamin D level > 100 nmol/L had higher forced vital capacity (FVC) in all the three models (1.17% higher, compared with the 50-100 nmol/L group in Model C). Low levels of serum 25OHD were independently associated with asthma, bronchitis, wheeze and chest tightness after three levels of adjustment for potential confounders. Higher vitamin D levels were associated with higher levels of lung function.

Vitamin D deficiency is associated with tibial bone pain and tenderness. A possible contributive role.

Vitamin D deficiency is associated with osteomalacia and a variety of musculoskeletal pain. This study aimed to determine the association of vitamin D deficiency with tibial bone pain and tenderness. Patients with leg pain, defined as local pain and tenderness over tibial bones for ≥6weeks were consecutively selected. Secondary causes of pain were excluded by appropriate clinical, radiological and laboratory examinations. Serum 25-hydroxyvitamin D (25-OHD) was assessed by enzyme-linked immunosorbent assay method and levels <20ng/mL were considered as deficiency. Age- and sex-matched subjects without leg pain served as controls. Multiple logistic regression analysis was used to determine associations. One hundred and eighteen patients and 114 controls aged 46.8±14.8 and 44.6±14.1years, respectively (P=0.93) were analyzed. Mean 25-OHD level was significantly lower (P=0.001) and the prevalence of 25-OHD deficiency was significantly higher in the patients as compared with the controls (75.4% vs. 23.6%), odds ratio (OR)=9.54 (95% CI, 5.22-17.45, P=0.001). There was a negative dose-response relationship between serum 25-OHD and tibial bone pain by OR=17.33 (95% CI, 6.48-46.3) in subjects with 25-OHD<10ng/mL, and OR=14.7 (95% CI, 6.35-34.6) in serum 25-OHD levels at 10-19.9ng/mL, and OR=2.58 (95% CI, 1.08-6.1) in those with 25-OHD at 20-29.9ng/mL as compared with 25-OHD≥30ng/mL. After controlling for demographic and biochemical factors, the association reached a stronger level of 19.8 (6.9-56.3) in subjects with serum 25-OHD<10ng/mL and 14.4 (5.8-34.6) in those with serum 25-OHD at levels of 10-19.9ng/mL and 1.85 (0.73-4.6) in 20-29ng/mL. These findings indicate a possible contributive role for serum 25-OHD deficiency in the development of pain and tenderness over the tibial bone.

Current Vitamin D Status in Healthy Japanese Infants and Young Children.

This study aimed to characterize serum 25-hydroxyvitamin D (25OH-D) values among Japanese children aged ≤48 mo. The study included 290 healthy infants and young children aged 0-48 mo (males/females=166/124) living in Shizuoka or Tokyo. The subjects were divided into three groups by age (Low Age: 0-5, Middle Age: 6-15, High Age: 16-48 mo). The vitamin D deficient state was defined as 25OH-D <12 ng/mL, the insufficient state as 12-20 ng/mL, and the sufficient state as >20 ng/mL. The seasonal variation of serum 25OH-D levels was also analyzed. The median serum 25OH-D levels in each group were: Low Age (n=50), 19 ng/mL; Middle Age (n=94), 30 ng/mL; and High Age (n=146), 30 ng/mL. The serum 25OH-D level was significantly lower in the Low Age group than in the other groups (p<0.01). Serum 25OH-D levels in summer and autumn (n=149) were significantly higher than in winter and spring (n=141) (33 vs. 25 ng/mL, p<0.01). In the Low Age group, there was a significant difference in serum 25OH-D levels between breast-fed infants (n=26) and formula-fed or mixed-fed infants (n=19) (12 vs. 32 ng/mL, p<0.01). However, there were no significant differences in 25OH-D levels between the two season classifications in either breast-fed or formula-fed and mixed-fed infants. Although clinical symptoms were not available, more than 75% of the breast-fed infants and 14.6% of infants and young children to whom food had been introduced were defined as having a vitamin D deficient or insufficient state. Breastfeeding seems one of the contributing factor to lower serum 25 OH-D levels among infants ≤5 mo of age.

Poultry By-products as a Potential Source of Nutrients

Objective: There has been a huge increase in numbers of serum 25-hydroxyvitamin D (25OHD) measurements in spite of uncertainty concerning the benefits of vitamin D supplementation, there is a sufficient serum 25OHD level and to interpret serum 25OHD measurements. Methods: 255 subjects who participated in a 5-years intervention study with vitamin D for the prevention of type 2 diabetes and who were allocated to placebo were included. Serum 25OHD levels were measured annually, and questionnaires on sunny vacations and vitamin D supplementation filled in. Results: The serum 25OHD levels were ~ 20 nmol/L higher in the summer than the winter months; those taking vitamin D supplements had ~ 5 nmol/L higher 25OHD levels than those not taking supplements; a recent sunny vacation increased the serum 25OHD levels 8-16 nmol/L; and there was a high degree of tracking of serum 25OHD with correlation coefficient (r) between baseline and the following annual measurements between 0.67 and 0.75. Conclusions: If considering a serum 25OHD level of 50 nmol/L as sufficient and that this level should be attained year-round, and taking season, vitamin D supplementation status and recent sunny vacation into account, a single measurement will in most situations be reliable and sufficient for making clinical decisions without need for numerous repeat measurements.