Effect of iron on serum 25-hydroxyvitamin D and 24,25-dihydroxyvitamin D concentrations

Enhancing vitamin D3 - iron blends via twin-screw dry granulation: Microstructural properties and cellular uptake analysis of vitamin D3

The aim of this study was to develop vitamin D3 (VD3) and iron (Fe) blended granules using Neusilin® US2 as an excipient. A central composite design of experiments was used for the continuous manufacturing process, considering VD3 and iron as independent variables and the bulk density, flow index, oil holding capacity, and color difference as response variables. The addition of VD3 had a significant effect on the powder flow properties. The X-ray diffraction and Scanning electron microscopy-energy dispersive X-ray analysis validated the presence of VD3 and Fe in the granules, whereas the variations in porosity and roughness were demonstrated by tomography and atomic force microscopy, respectively. The in vitro cellular uptake profile confirmed the absorption of VD3 in the breast cancer cell line MCF-7 with apparent apoptosis. These results could help in scaling up the process from laboratory to pilot scale in twin-screw granulation and boost the intervention of VitD3/iron deficiencies.

Effects of vitamin D prophylaxis on oral irontreatments of iron deficiency anemia

BACKGROUND

Iron deficiency anemia causes a decrease in immune response to infections, physical working capacity and response to metabolic stress. It also causes behavioral, perceptual and cognitive disorders. Therefore, as soon as iron deficiency anemia is diagnosed, it should be treated immediately. In this study, it was investigated retrospectively whether there was a difference in treatment efficacy between the administration of oral ferrous or ferric iron and vitamin D at the same time and at different time.

METHODS

A total of sixty patients under 1 year who attended the pediatrics outpatient clinic for pale and diagnosed with iron deficiency anemia. Patients were randomly divided into 4 groups. Anemia was defined as hemoglobin below <2 SD according to age and gender. Iron deficiency was definied with serum iron, iron-binding capacity, ferritin and transferin saturation below the range for age and gender appropriates. All patients were seen at the outpatient clinic for 1st, 3rd month of the treatment.

RESULTS

There were statistically significant differences between the groups in terms of increase in Hb values according to time (1^st month, 3^rd month, 1^st and 3^rd month). There was no statistically significant difference between the groups in terms of the recovery of anemia after treatment.

CONCLUSIONS

It was concluded that iron treatment in babies with iron deficiency anemia is not affected by the administration of vitamin D prophylaxis at the same time or at different times, and therefore both treatments can be administered at the same time to increase drug compliance.

Gluten-free diet attenuates the impact of exogenous vitamin D on thyroid autoimmunity in young women with autoimmune thyroiditis: a pilot study

Although both exogenous vitamin D and a gluten-free diet were found to reduce thyroid antibody titers, no study investigated interactions between gluten intake and vitamin D status in patients with autoimmune thyroid disorders. The aim of the present study was to assess whether the gluten-free diet determines the effect of vitamin D treatment on thyroid autoimmunity and thyroid function in young women with autoimmune (Hashimoto's) thyroiditis. The study compared two groups of euthyroid premenopausal women with this disorder, matched for thyroid antibody titers: 31 women with non-celiac gluten sensitivity complying for at least 12 months with the gluten-free diet and 31 unaffected sisters of women with non-celiac gluten sensitivity remaining without any dietary intervention. Plasma titers of thyroid peroxidase and thyroglobulin antibodies, as well as plasma concentrations of thyrotropin, free thyroid hormones, prolactin, 25-hydroxyvitamin D and high-sensitive C-reactive protein were measured at entry and after a six-month follow-up. Moreover, at both time points, the structure parameters of thyroid homeostasis were assessed. Although exogenous vitamin D decreased titers of thyroid peroxidase and thyroglobulin antibodies and increased 25-hydroxyvitamin D levels in each treatment group, this effect was less pronounced in patients on the gluten-free diet than in patients not following any dietary recommendations. Only in the latter group of patients, vitamin D increased SPINA-GT. Treatment-induced changes in thyroid peroxidase and thyroglobulin antibodies correlated with the impact of treatment on 25-hydroxyvitamin D levels. The obtained results suggest that gluten-free diet may impair beneficial effects of exogenous vitamin D in individuals with Hashimoto's thyroiditis.

Behavioral sleep medicine-The need for harmonization of clinical best practice outcome measures in children and adolescents with intellectual or developmental disabilities and restless sleep

In behavioral medicine, sleep disorders, insomnia in particular, may be considered comorbidities and precipitating factors to intellectual or developmental disabilities (IDD). Nevertheless, sleep alterations have often been neglected in favor of daytime features and symptoms, albeit simple behavioral nighttime observations may disclose hypermotor features that characterize restless sleep. The root of most hypermotor restlessness is linked to central iron deficiency. The latter is often exacerbated by vitamin D deficiency (VDD), which interferes with both dopaminergic and serotonergic mechanisms. In this way, an imbalance affecting daytime behavior and mood is created. Several sleep-related motor disorders such as bruxism, periodic and aperiodic leg movements, Restless Legs Syndrome (RLS), and Restless Sleep Disorder (RSD) are commonly seen in Attention Deficit Hyperactivity Disorder (ADHD) and Autism Spectrum Disorders (ASD). However, they are rarely diagnosed and often overlooked in affected children and adolescents. As a result, not only are these disorders not adequately addressed therapeutically, but their symptoms may be worsened by the side-effects of drugs used to contain disruptive daytime behavior, such as antipsychotics and antidepressants. In children with IDDs, obesity, inactivity and metabolic effects of antipsychotics often lead to Sleep Disordered Breathing (SDB), which is currently understood as an inflammatory state leading to "hyperactive" lethargy and further alterations of the hypoxic chain and vitamin D levels. Endorsing simple routine blood tests, including inflammatory markers such as C-reactive protein, ferritin, transferrin, and vitamin D levels, may favorably complement caregiver observations and ambulatory sleep recordings, leading to a sleep disorder diagnosis and consequent therapy. In fact, the treatment of SDB, RLS, and RSD has been copiously demonstrated to favorably impact vigilance, behavior, social competence, and academic skills in healthy and, to a greater extent, in IDD children. Thus, consulting and deliberating the root causes of functional and categorical diagnoses within a clinical framework may engender a more precise diagnosis and further benefit pediatric daytime and nighttime management of hyperactive behaviors.

The effect of iron dextran on vitamin D3 metabolism in SD rats

BACKGROUND

Iron and vitamin D (VD) is essential to health. Previous studies have shown that iron homeostasis has a potential effect on VD metabolism, but the mechanism is not fully understood.

OBJECTIVES

To explore the relationship between VD metabolism and iron metabolism, as well as the regulatory mechanism of iron on VD metabolism.

METHODS

40 male rats were fed adaptively for 7 days and randomly divided into control (C, n = 6 normal diet) group and model (M, n = 24 iron deficient diet) by simple randomization, the latter was used to establish iron deficiency anemia (IDA) model. After 6 weeks of feeding, the M group was randomly divided into: iron deficiency group (DFe), low iron group (LFe), medium iron group (MFe) and high iron group (HFe) by block randomization. Different doses of iron dextran (based on iron content (100 g·bw·d)): 0, 1.1, 3.3 and 9.9 mg) were given respectively. After 4 weeks, the rats were anesthetized with 8% chloral hydrate, Blood (collected from the abdominal aorta), liver and kidney tissues were collected. The serum and tissues were separately packed and frozen at -80℃ for testing.

RESULTS

The results showed that the levels of hemoglobin (Hb), red blood cell (RBC), serum iron (SI), liver iron, and kidney iron in DFe group were lower than those in the other four groups, while the levels of total iron-binding capacity (TIBC), transferrin (TF) and transferrin receptor (Tfr) in DFe group were higher than those in other groups; The serum levels of 25-(OH)D₃ and 1,25-(OH)₂D₃ in DFe group were significantly lower than those in C group (P < 0.05). The correlation analysis showed that the levels of 25-(OH)D₃ and 1,25-(OH)₂D₃ were negatively correlated with TIBC, TF and Tfr no correlation with SI. Western blotting, immunofluorescence, and q-PCR results showed that compared with C group, the protein and gene expressions of CYP2R1, CYP27A1, and CYP24A1 in DFe group were down-regulated, and the expression of CYP27B1 protein and gene was up-regulated in DFe group.

CONCLUSION

Iron may be involved in the metabolism of VD₃ by regulating the expression of VD₃ hydroxylase, suggesting that appropriate iron supplementation might promote the activation of VD₃.

Vitamin D deficiency in young children with iron deficiency in Misan province, Iraq

This study aimed to assess vitamin D status and its association with iron status in young Iraqi children. A total of 95 infants and toddlers with iron deficiency (ages ranging from 6 to 24 months) and an equal number of 95 healthy subjects with normal hemoglobin (Hb) and sufficient ferritin level with matching age were included as a control group. A specially designed questionnaire was used to collect data. The cases were classified into iron deficiency (ID) and iron deficiency anemia (IDA) according to hemoglobin and ferritin levels. The cases and control groups were subdivided into vitamin insufficiency (VDI), vitamin D deficiency (VDD), and vitamin D sufficiency groups according to 25-hydroxyvitamin D [25(OH)D] levels. Young children with IDA have significantly lower serum levels of 25(OH) D compared with ID and control groups (p<0.05). According to iron status, VDI and VDD were present in 20% and 70% of IDA, 25.7% and 60%of ID, and 26.3% and 30.5% of control groups, respectively, with a significant difference in vitamin D level (p<0.05) among studied groups. A significant positive correlation (p=0.000) was found between serum ferritin level and 25(OH) D level in studied patients. Young children with severe iron deficiency have a higher prevalence of vitamin D deficiency, and there was a significant positive correlation between serum ferritin level and 25(OH) D levels among studied children.

Rapid and Effective Vitamin D Supplementation May Present Better Clinical Outcomes in COVID-19 (SARS-CoV-2) Patients by Altering Serum INOS1, IL1B, IFNg, Cathelicidin-LL37, and ICAM1

Background: We aimed to establish an acute treatment protocol to increase serum vitamin D, evaluate the effectiveness of vitamin D3 supplementation, and reveal the potential mechanisms in COVID-19. Methods: We retrospectively analyzed the data of 867 COVID-19 cases. Then, a prospective study was conducted, including 23 healthy individuals and 210 cases. A total of 163 cases had vitamin D supplementation, and 95 were followed for 14 days. Clinical outcomes, routine blood biomarkers, serum levels of vitamin D metabolism, and action mechanism-related parameters were evaluated. Results: Our treatment protocol increased the serum 25OHD levels significantly to above 30 ng/mL within two weeks. COVID-19 cases (no comorbidities, no vitamin D treatment, 25OHD <30 ng/mL) had 1.9-fold increased risk of having hospitalization longer than 8 days compared with the cases with comorbidities and vitamin D treatment. Having vitamin D treatment decreased the mortality rate by 2.14 times. The correlation analysis of specific serum biomarkers with 25OHD indicated that the vitamin D action in COVID-19 might involve regulation of INOS1, IL1B, IFNg, cathelicidin-LL37, and ICAM1. Conclusions: Vitamin D treatment shortened hospital stay and decreased mortality in COVID-19 cases, even in the existence of comorbidities. Vitamin D supplementation is effective on various target parameters; therefore, it is essential for COVID-19 treatment.

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

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

Are serum vitamin D, calcium and phosphorous associated with restless leg syndrome? A systematic review and meta-analysis

BACKGROUND

It is hypothesized that vitamin D deficiency, and calcium/phosphate imbalance could be involved in the pathophysiology of restless leg syndrome (RLS). This systematic review and meta-analysis of observational studies were carried out to reach a firm conclusion regarding the possible association between vitamin D, calcium and phosphorous levels with RLS in end-stage renal disease (ESRD) patients, other comorbidities and healthy population.

METHODS

PubMed, Scopus, ISI Web of Science, and Cochrane's library were systematically searched up to June 2020. Quality assessment of the included observational studies was performed using Newcastle-Ottawa Quality Assessment Scale. Statistical analyses were done using STATA 11.2. A P-value <0.05 were considered statistically significant.

RESULTS

A total of 36 studies involving 9590 participants were included in this systematic review and meta-analysis. We found that serum vitamin D level is significantly lower (WMD -3.39 ng/mL; 95% CI, -5.96 to -0.81; P = 0.010; I² = 86.2%) and phosphorous (SMD 0.19; 95% CI, 0.04-0.34; P = 0.011; I² = 83.6%) is significantly higher in RLS individuals compared to the non-RLS individuals. However, the mean difference of serum calcium was not significant in comparison between RLS and control groups (SMD -0.01; 95% CI, -0.19 to 0.18; P = 0.957; I² = 89.2%).

CONCLUSION

Results revealed a significant association between serum vitamin D and phosphorous with RLS. However, further prospective cohort studies and clinical trials are needed for better understanding of the relationship between these variables.

Malnutrition in obesity before and after bariatric surgery

Bariatric surgeries are considered the only effective way of weight loss therapy in morbidly obese patients, i.e. body mass index ≥ 35. However, micronutrient deficiencies and malnutrition are common after most bariatric procedures and thus, pre- and postoperative nutritional assessment and corrections are advised. The present review is presented in an effort to describe in some detail about prevalence, and mechanisms of macro- and micronutrient deficiencies in obese and post-bariatric surgery individuals. We also aimed to summarize the data on screening and supplementation of macro- and micronutrients before and after bariatric surgeries.

The Association between Iron and Vitamin D Status in Female Elite Athletes

Vitamin D may influence iron metabolism and erythropoiesis, whereas iron is essential for vitamin D synthesis. We examined whether vitamin D deficiencies (VDD) are associated with reduced iron status and whether progressive iron deficiency (ID) is accompanied by inferior vitamin D status. The study included 219 healthy female (14–34 years old) athletes. VDD was defined as a 25(OH)D concentration < 75 nmol/L. ID was classified based on ferritin, soluble transferrin receptor (sTfR), total iron binding capacity (TIBC) and blood morphology indices. The percentage of ID subjects was higher (32%) in the VDD group than in the 25(OH)D sufficient group (11%) (χ² = 10.6; p = 0.001). The percentage of VDD subjects was higher (75%) in the ID than in the normal iron status group (48%) (χ² = 15.6; p = 0.001). The odds ratios (ORs) for VDD increased from 1.75 (95% CI 1.02–2.99; p = 0.040) to 4.6 (95% CI 1.81–11.65; p = 0.001) with progressing iron deficiency. ID was dependent on VDD in both VDD groups (25(OH)D < 75 and < 50 nmol/L). The ID group had a lower 25(OH)D concentration (p = 0.000). The VDD group had lower ferritin (p = 0.043) and iron (p = 0.004) concentrations and higher values of TIBC (p = 0.016) and sTfR (p = 0.001). The current results confirm the association between vitamin D and iron status in female athletes, although it is difficult to assess exactly which of these nutrients exerts a stronger influence over the other.

Vitamin D status among women aged 40 years and above in a rural area of West Bengal: A community-based study

Introduction:

Vitamin D deficiency is a recognized pandemic. Even in a tropical country like India, where there is plentiful sunshine, vitamin D deficiency is widely prevalent. Adult females, particularly those above the age of 40, are mostly affected because vitamin D determines the pattern of post-menopausal bone loss and age-related osteoporosis.

Methods:

A community-based cross-sectional study was conducted from April–December 2017 among 194 women aged 40 years and above residing in the village of Singur, West Bengal. For this study, multistage random sampling method was used. Each respondent was interviewed using a structured schedule to collect data on sociodemographic characteristics, dietary pattern, their daily sun exposure, tobacco use, and morbidity profile. Individuals with 25OH vitamin D <30ng/ml were said to have vitamin D insufficiency (VDI). Data entry and analysis was done using SPSS version 16.0.

Results:

Out of 194 participants, 70.6% had VDI (Vitamin D deficient-19.6%, Vitamin D insufficient-51.0%). Mean (SD) age of the participant was 56.9 (8.9) years. Mean (SD) duration of daily sun exposure was 138.5 (59.2) minutes. 74 (38.1%) had overweight/obesity. Only 73 (37.6%) had adequate diet. Test results revealed low SES, decreasing duration of daily sun exposure, diabetes, overweight/obesity, and inadequate diet as significant predictors of VDI, explaining 39.3% of the variance with model fit.

Conclusion:

The study has identified factors associated with VDI among the study participants. Emphasis on promoting consumption of vitamin D rich food and with vitamin D supplements, outdoor activities to increase sun exposure, maintaining optimum body weight, and strictly adhering to diabetes control will help alleviate the problem at large.

Bone health assessment of food allergic children on restrictive diets: a practical guide

BACKGROUND

Food allergy in childhood is on the rise globally and is managed with avoidance diets; recent case reports of food allergic children with nutritional rickets in the literature highlight the importance of close monitoring of bone health in this population.

METHODS

There is no consensus as yet with regard to bone health evaluation in food allergic children; therefore, extensive literature search was performed and the existing evidence is presented, along with a relevant algorithm.

RESULTS

Children allergic to cow's milk protein or presenting with allergy in more than three food items, as well as patients with severe allergic phenotypes or comorbidities known to affect the skeleton, seem to be at risk of metabolic bone disorders. As a practical guide, suspicious cases can be investigated with basic bone profile, whereas more severe cases (persistent bone pain and fractures) may undergo advanced bone health assessment, with bone mineral density (BMD) and metabolic bone markers' evaluation. Of note, these diagnostic steps call for further studies in the field of food allergy, as they are not performed as a routine. Evidence is accumulating with regard to vitamin D deficiency, osteopenia and imbalanced bone metabolism in those food allergic children who show poor dietary compliance or have inadequate medical supervision.

CONCLUSIONS

Ensuring optimal bone accrual in a food allergic child is an important task for the clinician and requires close monitoring of the restrictive diet and prompt therapeutic intervention, in an effort to avoid rickets or osteopenia.

Serum 25-hydroxyvitamin D and bone turnover markers in Palestinian postmenopausal osteoporosis and normal women

This study evaluated the association of vitamin D and bone markers with the development osteoporosis in Palestinian postmenopausal women. Even though vitamin D deficiency was very high for the recruited subjects, it was not associated with osteoporosis except for bones of the hip. Age and obesity were the strongest determining factors of the disease.

PURPOSE

The purpose of this study was to investigate the association of bone mineral density (BMD) with serum vitamin D levels, parathyroid hormone (PTH), calcium, obesity, and bone turnover markers in Palestinian postmenopausal women.

METHODS

Three hundred eighty-two postmenopausal women (≥45 years) were recruited from various women clinics for BMD assessment (131 women had osteoporosis and 251 were normal and served as controls). Blood samples were obtained for serum calcium, PTH, 25(OH)D, bone formation (N-terminal propeptide (PINP)), and bone resorption (serum C-terminal telopeptide of type I collagen (CTX1)) markers.

RESULTS

Women with osteoporosis had statistically significant lower mean weight, height, body mass index (BMI), and serum calcium (p < 0.05) compared to controls. No significant differences were detected between the mean values of bone turnover markers (CTX and PINP), 25(OH)D, and PTH of the two groups. Women with vitamin D deficiency (severe and insufficiency) represented 85.9% of the study subjects. Multiple and logistic regression showed that age and BMI significantly affected BMD and vitamin D had a significant association with BMD only at the lumbar spine. BMI was positively correlated with BMD and PTH but negatively correlated with vitamin D. Logistic regression showed that the odds ratio (OR) for having osteoporosis decreased with increasing BMI (overweight OR = 0.11, p = 0.053; obese OR = 0.05, p = 0.007).

CONCLUSIONS

There was no direct correlation between BMD and PTH, bone turnover markers, and vitamin D except at the lumbar spine. A negative correlation between BMD and age and a positive correlation with BMI were observed. The protective effect of obesity on osteoporosis was complicated by the effect of obesity on vitamin D and PTH.

Effects of Iron on Vitamin D Metabolism: A Systematic Review

Vitamin D is a prohormone nutrient, which is involved in skeletal and extra-skeletal functions. Iron is another essential nutrient that is necessary for the production of red blood cells and oxygen transport. This element plays important roles in enzymatic systems including those required for Vitamin D activation. To the best of our knowledge, there is no exclusive review on the relationship between iron deficiency anemia (IDA), as the most prevalent type of anemia, and Vitamin D deficiency and the effect of recovery from iron deficiency on Vitamin D status. The aim of this study was to conduct a systematic search of observational and clinical trials in this field. The databases of PubMed, ProQuest, Cochrane Library, ISI Web of Knowledge, and SCOPUS were searched comprehensively. English-language human studies conducted on iron deficient patients or interventions on the effect of iron therapy on Vitamin D were extracted (n = 10). Our initial search yielded 938 articles. A total of 23 papers met the inclusion criteria. Thirteen studies were excluded because they were not relevant or not defining anemia types. The final analysis was performed on ten articles (3 cross-sectional and 7 interventional studies). Observational data indicated a positive relationship between iron status and Vitamin D, while trials did not support the effectiveness of iron supplementation on improving Vitamin D status. The mechanism underlying this association may involve the reduction of the activation of hydroxylases that yield calcitriol. Future randomized controlled trials with large sample sizes and proper designs are needed to highlight underlying mechanisms.

Associations between Vitamin D Status and Type 2 Diabetes Measures among Inuit in Greenland May Be Affected by Other Factors

OBJECTIVE

Epidemiological studies have provided evidence of an association between vitamin D insufficiency and type 2 diabetes. Vitamin D levels have decreased among Inuit in Greenland, and type 2 diabetes is increasing. We hypothesized that the decline in vitamin D could have contributed to the increase in type 2 diabetes, and therefore investigated associations between serum 25(OH)D3 as a measure of vitamin D status and glucose homeostasis and glucose intolerance in an adult Inuit population.

METHODS

2877 Inuit (≥18 years) randomly selected for participation in the Inuit Health in Transition study were included. Fasting- and 2hour plasma glucose and insulin, C-peptide and HbA1c were measured, and associations with serum 25(OH)D3 were analysed using linear and logistic regression. A subsample of 330 individuals who also donated a blood sample in 1987, were furthermore included.

RESULTS

After adjustment, increasing serum 25(OH)D3 (per 10 nmol/L) was associated with higher fasting plasma glucose (0.02 mmol/L, p = 0.004), 2hour plasma glucose (0.05 nmol/L, p = 0.002) and HbA1c (0.39%, p<0.001), and with lower beta-cell function (-1.00 mmol/L, p<0.001). Serum 25(OH)D3 was positively associated with impaired fasting glycaemia (OR: 1.08, p = 0.001), but not with IGT or type 2 diabetes.

CONCLUSIONS

Our results did not support an association between low vitamin D levels and risk of type 2 diabetes. Instead, we found weak positive associations between vitamin D levels and fasting- and 2hour plasma glucose levels, HbA1c and impaired fasting glycaemia, and a negative association with beta-cell function, underlining the need for determination of the causal relationship.

An evaluation of sleep quality and the prevalence of restless leg syndrome in vitamin D deficiency

Vitamin D is known to increase levels of dopamine and its metabolites in the brain and also protects dopaminergic neurons against dopaminergic toxins. The aims of the study were to assess the frequency and symptom severity of restless leg syndrome (RLS) and sleep quality in vitamin D deficiency. A total of 102 patients were enrolled in this cross-sectional study, comprising 57 vitamin D deficient patients as Group 1 and 45 patients with normal levels of vitamin D as Group 2. RLS was diagnosed according to the International RLS Study Group (IRLSSG) diagnostic criteria. Symptom severity was assessed using the IRLSSG rating scale and sleep quality was measured with the Pittsburgh sleep quality index (PSQI). RLS incidence was higher in Group 1 (p = 0.034). The PSQI scores were higher in Group 1 and the difference between the groups was determined as statistically significant (p < 0.05). No statistically significant difference was determined in respect of the clinical evaluation and the IRLSSG Symptom Severity Scale between the patients in Group 1 diagnosed with RLS and the patients in Group 2 diagnosed with RLS (p > 0.05). The findings of this study support the hypothesis that RLS is more frequent and more severe in vitamin D deficiency and indicate a negative effect of vitamin deficiency on sleep parameters.

Plasma fibroblast growth factor 23 concentration and iron status. Does the relationship exist in the elderly population?

OBJECTIVE

Fibroblast growth factor 23 (FGF23) is a phosphaturic agent involved in calcium-phosphate homeostasis. Recent findings show that iron deficiency and inflammation regulate FGF23 release and/or biodegradation. Iron deficiency is frequently observed in the elderly, therefore the aim of this study was to find out if iron deficiency is independent from low grade inflammatory factors affecting both forms of FGF23 that are detectable in circulation in a large population-based study of elderly subjects.

DESIGN AND METHODS

The analysis included 3780 elderly (1798 females) PolSenior study participants and assessed levels of phosphorus, calcium, iron, ferritin, interleukin 6, C-reactive protein (hs-CRP), intact (iFGF23), and c-terminal FGF (cFGF23). The analysis was performed for all subjects and terciles of serum iron levels in relation to hs-CRP were calculated.

RESULTS

The highest plasma cFGF23 and iFGF23 concentrations were found in subjects with the lowest serum iron levels (p<0.001). The effect of low grade inflammation was markedly weaker and affected only iFGF23 levels. The adjusted serum levels of hs-CRP, iPTH, phosphorus, and 25-(OH)-D3 analysis revealed that plasma iFGF23 and cFGF23 levels were almost unchanged up to a serum iron level of 59.3 ng/mL and 57.3 ng/mL respectively and then were nearly linearly increasing by 0.285 pg/mL and 3.742 RU/mL for each unit of serum iron increase.

CONCLUSIONS

Low iron levels are associated with increased levels of both cFGF23 and iFGF23, independent of low grade inflammation. A similar analysis of cFGF23 and iFGF23 does not suggest enhanced biodegradation of iFGF23 induced by iron deficiency.

The Role of 25-Hydroxy Vitamin D Deficiency in Iron Deficient Children of North India

Extensive data from animal and human studies indicate a role of vitamin D in erythropoiesis. Iron and vitamin D deficiencies are implicated with adverse health effects in children even if they are asymptomatic. The potential relationship between the two remains poorly understood. A cross-sectional study was performed in the period from 1st May 2012 through 30th April 2013 and subjects were classified into vitamin D deficiency (VDD), vitamin D insufficiency (VDI) and vitamin D sufficiency (VDS) groups according to their 25(OH) D levels. A total of 263 children were included in the analysis. Anaemia was present in 66 % of 25(OH) D deficient subjects compared with 35 % in vitamin D sufficient individuals (p < 0.0001). The association of breast feeding and development of VDD was also significant (p < 0.05). Serum levels of 25(OH) D were found lower in female sex and if the analysis was performed in the winter/spring season. Physicians should therefore assess vitamin D levels in all anaemic children and ensure adequate supplementation to prevent deficiencies.

Serum 25-hydroxyvitamin D levels in restless legs syndrome patients

OBJECTIVE

Restless legs syndrome is characterised by discomfort during rest and an urge to move the limbs that is accompanied by abnormal sensations. Studies on disease pathophysiology have focused on dopaminergic dysfunction. Vitamin D may play an important role in dopamine function, but the role of vitamin D in restless legs syndrome has not been examined. We compared the serum vitamin D levels of RLS patients and matched controls and explored the correlation of plasma vitamin D levels with disease severity.

PATIENTS/METHODS

We measured serum 25-hydroxyvitamin D levels in 36 patients with restless legs syndrome and compared them to 38 healthy control subjects.

RESULTS

The mean serum 25-hydroxyvitamin D levels were 7.31±4.63 ng/mL in female patients with restless legs syndrome and 12.31±5.27 ng/mL in female control subjects (p=0.001). We found a significant inverse correlation between vitamin D levels and disease severity in females (p=0.01, r=-0.47).

CONCLUSION

The mean serum vitamin D levels were lower in female patients with restless legs syndrome. Low vitamin D levels may cause dopaminergic dysfunction in restless legs syndrome patients. Further studies are required to confirm these results.

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

Objective

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

Design

Cross-sectional prospective study.

Setting

Department of Paediatrics, Princess Rahma Teaching Hospital, Jordan.

Subjects

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

Results

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

Conclusions

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

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

BACKGROUND

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

METHODOLOGY/PRINCIPAL FINDINGS

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

CONCLUSIONS/SIGNIFICANCE

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

Hypovitaminosis D is common among pulmonary tuberculosis patients in Tanzania but is not explained by the acute phase response

Vitamin D is essential to immune function, but little is known about the vitamin D status in equatorial populations. A cross-sectional study was conducted among pulmonary tuberculosis (PTB) patients in Mwanza, Tanzania to identify the predictors of their vitamin D status. Data on sociodemography, season, and intake of food, alcohol, tobacco, and soil were collected, anthropometric measurements taken, and serum alpha(1)-antichymotrypsin (ACT), ferritin and soluble transferrin receptor (sTfR), and serum 25-hydroxy-(ergocalciferol+cholecalciferol) [25(OH)D] determined. Of the 655 patients studied, 79.7% (508/637) were culture-positive (PTB+) and 47.2% HIV infected. Mean serum ACT, an acute phase reactant, was 0.73 +/- 0.25 g/L with 69.2% >0.6 g/L. Mean serum 25(OH)D was 86.6 +/- 32.9 nmol/L, with 41.2% <75 nmol/L. Serum 25(OH)D was highest during the harvest season, May to July, compared with the remaining year. Single subjects had lower [10.4 (95% CI 4.0; 16.9) nmol/L] serum 25(OH)D concentrations than married subjects and PTB+ patients had concentrations lower [8.2 (95% CI 1.5; 14.9) nmol/L] than PTB- patients. Serum 25(OH)D increased with consumption of a large freshwater fish but not of small dried fish or other foods. BMI and serum TfR were positive predictors of serum 25(OH)D, whereas neither elevated serum ACT nor HIV were predictors. In conclusion, serum 25(OH)D is a valid measure of vitamin D status during the acute phase response. The lower concentrations in PTB+ patients may reflect lower sun exposure or increased utilization. The health consequences of hypovitaminosis D in low-income equatorial populations, at risk for both infectious and chronic diseases, should be studied.

Nutritional problems related to food allergy in childhood

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

Asymptomatic rickets in adolescent girls

OBJECTIVE

Inadequate sunlight exposure and calcium intake during rapid growth at puberty lead to hypocalcemia, hypovitaminosis D and eventually to overt rickets. To determine serum biochemical findings of rickets in healthy 11-15 yr old girls, the effect of sunlight exposure and oral vitamin D supplementation on serum 25- hydroxy vitamin D and calcium administration in girls with abnormal findings during December 2002 through March 2003 in Tehran, Iran.

METHODS

Healthy middle school girls were selected for estimation of vitamin D, calcium and phosphorus intake by a three-day food recall. And measurement of serum calcium, phosphorus, parathyroid hormone, alkaline-phosphatase and 25- hydroxyvitamin D concentration. The girls with abnormal findings divided in two groups. Hypovitaminosis D girls subdivided into two groups, supplementary sunlight exposure and vitamin- D administrated for them and calcium administration for the second group for 20 days.

RESULTS

Of 414 girls, the mean daily vitamin D acquirement and calcium intake were 119 +/- 52 IU and 360 +/- 350 mg among all girls respectively. Mean serum 25-hydroxyvitamin D with two or more abnormal biochemical findings in 15 (3.6%) girls (group I) were 7.8 ng/ml and alkaline phosphatse with normal or low calcium in 29 (7%) girls (group II) was 1187 IU/L. Mean serum calcium was 8.2 mg % in 8 of 29 girls. Serum 25- hydroxyvitamin D before and after sunlight exposure was 7.1 +/- 1.9 ng/ml and 13.9 +/- 2.4 ng/ml and vitamin D administration was 7.4 +/- 1.8 ng/ml (group Ia) and 27.9 +/- 4.2 ng/ml (group Ib) respectively. Serum alkaline phosphatase before and after calcium administration were 1187 IU/L and 666 IU/L respectively.

CONCLUSION

We conclude that low daily calcium intake and vitamin D acquirement are two important problems in Iranian girls during rapid growth at puberty; therefore, for prevention of overt rickets calcium and vitamin D Supplementation appear to be necessary.

Meat consumption reduces the risk of nutritional rickets and osteomalacia

Endogenous vitamin D deficiency (low serum 25(OH)D3) is a necessary but insufficient requirement for the genesis of vitamin D-deficiency rickets and osteomalacia. The magnitude of the independent contributions of dietary factors to rachitic and osteomalacic risk remains uncertain. We reanalysed two weighed dietary surveys of sixty-two cases of rickets and osteomalacia and 113 normal women and children. The independent associations of four dietary variables (vitamin D, Ca, fibre and meat intakes) and daylight outdoor exposure with rachitic and osteomalacic relative risk were estimated by multivariate logistic regression. Meat and fibre intakes showed significant negative and positive associations respectively with rachitic and osteomalacic relative risk (RR; zero meat intake: RR 29·8 (95 % CI 4·96, 181), P<0·001; fibre intake: RR 1·53 (95 % CI 1·01, 2·32), P+0·043). The negative association of meat intakes with rachitic and osteomalacic relative risk was curvilinear; relative risk did not fall further at meat intakes above 60 g daily. Daylight outdoor exposure showed a significant negative association with combined relative risk (RR 0·33 (95 % CI 0·17, 0·66), P<0·001). Operation of the meat and fibre risk factors was related to sex, age and dietary pattern (omnivore/lactovegetarian), mainly determined by religious affiliation. The mechanism by which meat reduces rachitic and osteomalacic risk is uncertain and appears independent of revised estimates of meat vitamin D content. The meat content of the omnivore Western diet may explain its high degree of protection against nutritional rickets and osteomalacia from infancy to old age in the presence of endogenous vitamin D deficiency.

Impact of dietary and lifestyle on vitamin D in healthy student girls aged 11-15 years

OBJECTIVE

To study daily intake of calcium, phosphorus and vitamin D, to determine the biochemical findings of rickets and the effect of sunlight exposure and vitamin D supplementation in school girls with hypovitaminosis D.

METHODS

A cross-sectional study was conducted on school girls aged 11-15 years selected randomly from various areas of Tehran, Iran. Dietary information and amount of sunlight exposure were estimated by a 7 day recalling method using self-reported questionnaire. Hypovitaminosis D defined as low serum 25-hydroxyvitamin D concentration with two or more others abnormal biochemical findings. Girls with hypovitaminoses D were randomly divided into two groups. The faces and hands of girls in group 1 were exposed to sunlight for one hour per day for twenty days, while those in group 2 were administered vitamin D capsules, 50,000 IU per day for the same period.

RESULTS

four-hundred fourteen girls evaluated, mean daily calcium intake, sunlight exposure and vitamin D acquirement were 360 mg, 10 minutes and 119 IU, respectively. Mean serum 25-hydroxyvitamin D concentration was 30 ng/ml among all girls whereas in 15 (3.63%) of 414 girls was 7.8 ng/ml. Abnormal biochemical findings in these girls included hypocalcemia (n=4), hypophosphatemia (n=5), raised serum alkaline phosphatase (n=13), and parathyroid hormone (n=15). After intervention, mean serum 25-hydroxyvitamin D concentration in sunlight exposure (n=8) and vitamin D (n=7) supplementation increased to 14.4+/-4 ng/ml and 23+/-4 ng/ml respectively. There was a significant difference between the two groups (p<0.05).

CONCLUSION

Vitamin D deficiency developed in rapid growth period of girls without clear clinical rickets in sunny temperate climate city in Iran which vitamin D supplementation improved biochemical findings better than sunlight exposure.

Predictors and relationships of serum 25 hydroxyvitamin D concentration with bone turnover markers, bone mineral density, and vitamin D receptor genotype in Emirati women

OBJECTIVES

To determine factors influencing serum 25 hydroxyvitamin D (25OHD) concentration and relationships between serum 25OHD concentration, bone turnover markers, bone mineral density (BMD), and vitamin D receptor (VDR) genotype in Emirati women.

METHODS

Serum 25OHD, parathyroid hormone (PTH), osteocalcin (OC), vitamin D binding protein (VDBP), and urinary deoxypyrdinoline (UDPD) concentrations and VDR genotype were determined in Emirati women volunteers who were participating in a study aiming at establishing a reference database for BMD.

RESULTS

Serum 25OHD concentration in the 259 women volunteers was 25.3 +/- 10.8 nmol/l (mean +/- SD), and all had vitamin D deficiency (25OHD <80 nmol/l). Mean serum 25OHD was highest in April (29.2 +/- 13.0 nmol/l), which marks the end of the short and cooler winter season, and lowest in August (18.2 +/- 5.9 nmol/l). No significant difference in 25OHD concentration was noted among Emirati women wearing different dress styles, but the mean serum 25OHD was significantly lower in comparison with non-Arab Caucasian women volunteers who dressed in a Western style (P < 0.001). Serum 25OHD correlated positively with age (r = 0.2), number of pregnancies (r = 0.16), dietary vitamin D intake (r = 0.15), serum calcium (r = 0.14), phosphorus (r = 0.14), VDBP (r = 0.15), and urinary calcium/creatinine (r = 0.2), and inversely with PTH (r = -0.22), OC (r = -0.13), and UDPD/creatinine (r = -0.15); P < 0.05 for all correlations. Multiple linear regression analysis showed that age, dietary vitamin D intake, multivitamin intake, and cooler season were independent positive predictors of serum 25OHD concentration (R(2) = 0.18). The frequencies of VDR genotypes were 36% GG, 44.1% AG, and 19.9% AA. Allele frequencies were 58% for G allele and 42% for A allele and were in Hardy-Weinberg equilibrium (x(2) = 1.44; P > 0.1). There was no statistically significant influence of VDR genotype on bone turnover or BMD.

CONCLUSIONS

Vitamin D deficiency is highly prevalent in Emirati women and appears largely attributable to insufficient sunlight exposure. It is associated with increased bone turnover. VDR genotype does not appear to influence bone turnover markers or BMD in Emirati women.

Bioavailability of vitamin D2 from irradiated mushrooms: an in vivo study

Vitamin D2 from irradiated edible mushrooms might present a possible dietary source of this vitamin, subject to its bioavailability. Having previously optimized a method for the conversion of ergosterol in mushrooms to vitamin D2, this paper examines the vitamin D-enriched mushrooms (Lentinula edodes) for their bioavailability of the vitamin, using an animal model. Thirty male Wistar rats were fed for 1 week with a diet deficient in vitamin D. After this 1-week period, six rats were randomly selected and killed for analysis of initial bone mineral density, and serum level of 25-hydroxyvitamin D. A group of twelve rats of the test animals received 1 mug of vitamin D2 from irradiated mushrooms for a period of 4 weeks until being killed. The remaining twelve rats were fed un-irradiated mushrooms at the same level to act as controls. At the end of a 4-week period, the mean serum 25-hydroxyvitamin D level of the experimental group was 129.42 (sd 22.00) nmol/l whereas it was only 6.06 (sd 1.09) nmol/l in the control group. Femur bone mineral density of the experimental group of animals was significantly higher (P<0.01) than the control group. In addition, serum Ca concentrations among groups were shown to be significantly higher (P<0.01). It may be concluded from the results that vitamin D2 from UV-irradiated mushrooms is well absorbed and metabolized in this model animal system. Significant increase in femur bone mineralization (P<0.01) was shown in the presence of vitamin D2 from irradiated mushrooms compared with the controls.

Rickets

Rickets, once thought vanquished, is reappearing. In some less developed countries it hardly went away. This seminar reviews the effects of genes, stage of development, and environment on clinical expression of the disease. Rickets can be secondary to disorders of the gut, pancreas, liver, kidney, or metabolism; however, it is mostly due to nutrient deficiency and we concentrate on this form. Although calcium deficiency contributes in communities where little cows' milk is consumed, deficiency of vitamin D is the main cause. There are three major problems: the promotion of exclusive breastfeeding for long periods without vitamin D supplementation, particularly for babies whose mothers are vitamin D deficient; reduced opportunities for production of the vitamin in the skin because of female modesty and fear of skin cancer; and the high prevalence of rickets in immigrant groups in more temperate regions. A safety net of extra dietary vitamin D should be re-emphasised, not only for children but also for pregnant women. The reason why many immigrant children in temperate zones have vitamin D deficiency is unclear. We speculate that in addition to differences in genetic factors, sun exposure, and skin pigmentation, iron deficiency may affect vitamin D handling in the skin or gut or its intermediary metabolism.

25-hydroxyvitamin D levels among healthy children in Alaska

OBJECTIVE

To determine vitamin D levels among children 6 to 23 months old receiving services from Women, Infants, and Children (WIC) programs in Alaska. Study design During 2001 and 2002, we recruited 133 children receiving services at seven WIC clinics, administered a risk factor questionnaire, and collected blood.

RESULTS

Fifteen (11%) and 26 (20%) children, respectively, had vitamin D levels <15 (considered abnormal) and 15 to <25 ng/mL (low normal). Compared with other children, children who still breast-fed were more likely to have a vitamin D level <15 ng/mL (relative risk [RR], 12; 95% confidence interval [CI], 3.6-39) or 15 to <25 ng/mL (RR, 3.6; 95% CI, 1.9-6.8) than > or =25 ng/mL. Among 41 still breast-feeding children, 14 (34%) took supplemental vitamins, and six (18%) were reported to have received vitamins every day.

CONCLUSIONS

Vitamin D deficiency is prevalent in Alaska. Breast-feeding in the absence of adequate vitamin D supplementation is the greatest risk factor.