Vitamin D deficiency and its predictors in a country with thirteen months of sunshine: the case of school children in central Ethiopia

Prevalence and Risk Factors of Vitamin D, Calcium and Phosphate Deficiency among Apparently Healthy Children Aged 6-24 Months in a Semi-urban Community in Southwest, Nigeria

BACKGROUND

Adequate levels of calcium, phosphate and Vitamin D are essential for bone physiology and growth, as well as preventing some common childhood illnesses. This study aimed to determine the prevalence of the deficiencies of these nutrients and factors affecting their serum levels in Nigerian children.

METHODS

This was a cross-sectional study that involved 220 apparently healthy children aged 6-24 months in Ikenne Local Government Area of Ogun State, Nigeria. Serum calcium and phosphate were assayed using the calorimetric method, while Vitamin D (25-OH Vitamin D) was assayed with ELISA.

RESULTS

The mean (±standard deviation [SD]) serum Vitamin D level was 55.07 ± 16.53 ng/ml, while the mean (±SD) serum calcium and phosphate were 2.27 ± 0.13 mmol/l and 1.28 ± 0.18 mmol/l, respectively. Eleven (5%) of the children had hypovitaminosis D, 23 (10.5%) had hypocalcaemia and 12 (5.5%) had hypophosphataemia. Factors found to be significantly associated with hypovitaminosis D included low consumption of milk and the use of a hijab veil, while malnutrition (both undernutrition and overnutrition) was significantly associated with hypocalcaemia.

CONCLUSION

The prevalence levels of hypovitaminosis D and hypophosphataemia were low, while hypocalcaemia was more common. Low milk consumption and use of a hijab veil were risk factors for hypovitaminosis D, while malnutrition was a risk factor for hypocalcaemia. Malnourished children, especially overnourished ones, should be routinely screened for hypocalcaemia because of its high prevalence among them.

Etiology and Biochemical Profile of Rickets in Tertiary Care Centres in Eastern India: A Retrospective Cross-sectional Study

Introduction

We aimed to describe the clinical, biochemical and etiological profile of patients referred with a provisional diagnosis of rickets in tertiary care centres. In addition, we tried to propose a diagnostic algorithm for the evaluation of such patients.

Methods

This was a retrospective cross-sectional study conducted in two tertiary care centres of West Bengal. Data of patients were retrieved between 2014 and 2021.

Results

Out of 101 children, 22 had conditions simulating rickets. Renal tubular acidosis (RTA) was the most common (53.2%) etiology of rickets, followed by phosphopenic rickets (PR) (22.8%) and calcipenic rickets (CR) (17.7%). The prevalence of true nutritional rickets (NR) was only 8.9%. Children with RTA had a significantly higher prevalence of chronic ill health (69%) and polyuria (95.2%). Weight standard deviation score (SDS) and body mass index (BMI) SDS scores were significantly lower in the RTA group compared to others. Around 90.5% of children with RTA, and none in the other groups, had hypokalemia. Biochemically, hypophosphatemia and elevated alkaline phosphatase (ALP) were present in all patients with PR and CR. Compared to CR, median serum phosphate was significantly lower in the PR group. A significant difference in ALP values was noticed in patients with hypophosphatemia (815 ± 627 IU/L) compared to those without (279 ± 204 IU/L). Plasma parathyroid hormone (PTH) of 100 pg/ml seemed useful to differentiate CR from other forms.

Conclusion

NR is uncommon in tertiary care centres. Children with rickets should be approached systematically with the estimation of ALP, phosphorus, creatinine, calcium, PTH and 25-hydroxy vitamin D to reach an etiological diagnosis.

Vitamin D-A New Therapeutic Target in the Management of Type 2 Diabetes Patients

Background: Vitamin D is a fat-soluble vitamin that prevents cardiovascular diseases and diabetes mellitus (DM). The present research aimed to study the impact of 25-hydroxyvitamin D (25(OH)D) level on the health status of patients with type 2 DM (T2DM) hospitalized in the "Pius Brînzeu" Emergency Clinical County University Hospital in Timisoara, Romania. Methods: The study retrospectively included 160 patients with T2DM who were clinically and biologically evaluated during hospitalization. Results: 13.1% of patients had optimal, 23.1% insufficient, and 63.8% deficient 25(OH)D values. Patients with 25(OH)D deficiency presented poorer glycemic control and were older, with higher weight, but had altered renal function, anemia, and lower iron values. Also, patients with associated neoplasia, diabetic neuropathy, cardiovascular disease (CVD), dementia, and grade 3 arterial hypertension (HTN) had lower values of 25(OH)D. An age > 55 years (sensitivity 69.9, specificity 82.5, AUROC 0.786, p < 0.001) and an HbA1c > 7.7% (sensitivity 89.3, specificity 92.9, AUROC 0.938, p < 0.001) predict 25(OH)D deficiency in T2DM patients. Conclusions: Vitamin D influences almost every system and organ in the body, so it should be a routine test for all patients with DM to correct the deficiency and prevent other diseases and complications.

Vitamin D Status in Osteoporotic and Diabetic Patients and Athletic Healthy Individuals from Northern Greece

Background

Vitamin D deficiency is recognised as a pandemic in the developed world. However, the importance of prudent sun exposure tends to be overlooked, which is responsible for this pandemic.

Methods

We investigated the vitamin D status in 326 adults, 165 females and 161 males: 99 Osteoporosis patients, 53 Type 1 Diabetes patients, 51 Type 2 Diabetes patients, and 123 Athletic Healthy individuals, from Northern Greece, through the measurement of total calcidiol in winter and summer by immunoenzymatic assay.

Results

In the Whole Sample 23.31% had severe deficiency, 13.50% mild deficiency, 17.48% insufficiency, and 45.71% adequacy at the end of winter. Mean concentrations differed significantly (p <0.001) between males and females. The prevalence of deficiency in the young was significantly lower than in the middle-aged (p = 0.004) and in the elderly (p <0.001), while it was significantly lower (p = 0.014) in the middle-aged than in the elderly. The best vitamin D status was found in the Athletic Healthy individuals, followed by the Type 1 and Type 2 Diabetic patients, while Osteoporotic patients had the poorest status. The difference in mean concentrations between winter and summer was significant (p <0.001).

Conclusions

Vitamin D status deteriorated with increasing age and it was better in males than in females. Our findings suggest that outdoor physical activity in a Mediterranean country can cover the vitamin D needs of the young and the middle-aged, but not of the elderly, without the need for dietary supplements.

Factors associated with infants' sunlight exposure among mothers attending the EPI unit of Wolkite University Specialized Hospital

BACKGROUND

Infant sunlight exposure in their early infancy is essential for the cutaneous synthesis of vitamin D. Vitamin D deficiency is highly prevalent due to inadequate exposure to sunlight. In Ethiopia, one in thirteen children had rickets, which could be prevented by sunlight exposure or supplementation. This study aimed to identify the practice of infants' sunlight exposure and associated factors among mothers attending the Expanded program immunization unit of Wolkite University Specialized Hospital.

METHOD

This study employed an institutional-based cross-sectional study design to collect data. Data were collected from 220 mothers using an interviewer-administered questionnaire. The study employed a systematic random sampling technique to reach the study participants. The collected data were entered into a computer using the software Epidata 3.1 version and exported to SPSS version 23 for statistical analysis. Descriptive and inferential analysis was conducted. Logistic regression analysis was done, and a statistical association was declared at a p-value < 5% and a 95% confidence interval(CI). Then the results were presented using a frequency table, figures, and description.

RESULT

A total of 220 infant-coupled mothers who visited the Expanded program immunization unit were included in the study. According to the current study, 67.3% of mothers had good practice with infants' sunlight exposure. Mothers' practice of infant sunlight exposure was affected by age of mothers 30-34 years, [AOR = 3.10, 95%CI (1.13, 8.51)], and age ≥35 years, [AOR = 4.49, 95%CI (1.20, 16.86)], and living in urban, [AOR = 1.94, 95%CI (1.053, 3.57)].

CONCLUSION

The current study showed that two-thirds (67.3%) of mothers had good practice of sunlight exposure to their infants. Factors that affect mothers' practice of infants' sunlight exposure are age and place of residence. Health professionals should provide health education for mothers on the benefits of infants' sunlight exposure.

Vitamin D May Be Connected with Health-Related Quality of Life in Psoriasis Patients Treated with Biologics

Suboptimal states of vitamin D may play a role in psoriasis evolution, but the interconnections have been studied over the past years with controversial results. Although a peerless therapy among moderate to severe types of psoriasis, the therapeutic effectiveness of biological therapy may vary unforeseeably between patients and leads to biologics switch. We conducted a pilot study in patients diagnosed with psoriasis and treated with biologics, the purpose of which was to explore the prevalence of suboptimal states of vitamin D, especially in the group of patients characterized by the failure of previous biologics, and to investigate the associations between vitamin D levels and psoriasis, regarding aspects such the severity of the disease and quality of life. Their current result of latent tuberculosis infection (LTBI) was also considered concerning a feasible relationship with vitamin D levels. From July to December 2021, 45 patients corresponding to our inclusion criteria were assessed. Variables such as Psoriasis Area and Severity Index (PASI) score and the Dermatology Life Quality Index (DLQI) score, as well as vitamin D serum concentrations and their LTBI result, were recorded for them. Lower serum concentrations of vitamin D were not more common in patients characterized by failure to previous biologics (p = 0.443), but we concluded a weak correlation between the DLQI score and vitamin D (rho = -0.345, p-value = 0.020), although a statistically insignificant result was obtained between vitamin D and the PASI score (rho = -0.280, p-value = 0.062), and with the LTBI result (rho = -0.053, p-value = 0.728). These results establish a connection between higher levels of vitamin D and a better outcome of psoriasis from the perspective of the patient's quality of life, with no significant association with psoriasis severity and no significant prevalence of suboptimal states among patients that failed previous biologics compared to those with a continuously good response.

Vitamin D binding protein gene polymorphisms are associated with lower plasma 25-hydroxy-cholecalciferol concentrations in Ethiopian lactating women

Ethiopian women have been reported to have low plasma 25-hydroxy-cholecalciferol (25(OH)D) concentrations despite an abundance of sunshine. Low dietary vitamin D intake, limited skin exposure to sun, and genetics are among factors suggested to affect vitamin D status in this population. In this study (Clinical Trial NCT02210884), we hypothesized that polymorphisms in the vitamin D binding protein (VDBP) gene (rs7041, rs4588) are associated with reduced plasma 25(OH)D concentrations in Ethiopian women. Lactating Ethiopian women (n = 110) were randomly assigned to weekly administration of vitamin D3 (15,000 IU) or a placebo. Plasma 25(OH)D was measured at baseline (within 2 weeks of delivery, before supplementation) and at 3, 6, and 12 months after delivery. Associations between VDBP polymorphism status for rs7041 and rs4588 and plasma 25(OH)D were determined by analysis of variance and multiple linear and logistic regressions. Multiple linear regression with maternal age as a covariate revealed that rs7041 is associated with reduced plasma 25(OH)D (P = .021) and more risk alleles at rs7041 and rs4588 are associated with reduced plasma 25(OH)D (P = .017). Logistic regression models for vitamin D insufficiency showed that additional risk alleles for rs7041 and rs4588 are associated with increased odds ratios (OR = 1.66; 95% CI, 1.10-2.62; P = .019) for plasma 25(OH)D below 40 nmol/L. Supplementation increased plasma 25(OH)D at 3 months in women with fewer risk alleles and across all genotypes at 6 and 12 months. VDBP polymorphisms may contribute to vitamin D insufficiency in Ethiopian lactating women. Furthermore, VDBP polymorphisms may blunt short-term responses to vitamin D supplementation and require longer periods of intervention.

Vitamin D status and determinants in Indian children and adolescents: a multicentre study

Studies performed on Indian children to assess vitamin-D status have been on small sample sizes, limited to specific geographical locations and used non-standard methods to measure 25(OH)D₃. This multicentre study assessed 25(OH)D₃ concentrations from dried blood spots (DBS) in 5–18-year-old Indian children and adolescents using a standardized protocol and identified factors contributing towards vitamin D deficiency. Cross-sectional, observational school-based study was conducted by multi-stage stratified random sampling. A city and nearby village were selected from 6 Indian states covering wide geographical areas. Demography, anthropometry, body-composition, dietary-intakes and DBS samples were collected. 25(OH)D₃ was assessed from DBS using Liquid chromatography with tandem-mass spectrometry. Vitamin-D status was assessed in 2500 children; with additional data collected on a subset (n = 669) to assess predictors. Mean vitamin-D concentration was 45.8 ± 23.9 nmol/L, 36.8% of subjects had sufficient vitamin-D (> 50 nmol/L); rural subjects and boys had higher concentrations (p < 0.05). On regression analysis, younger age, female-gender, overweight and urban residence significantly contributed to deficiency. More than half the Indian children/adolescents were vitamin-D deficient or insufficient. Our study reinforces vitamin-D deficiency as a major public health problem and the need for supplementation, food fortification and educating the population as initiatives required to improve sufficiency status.

Serum vitamin D status among healthy children in Hainan, South China: a multi-center analysis of 10,262 children

BACKGROUND

There are limited data regarding the prevalence and risk factors relating to vitamin D deficiency (VDD) in children of Hainan, a tropical city with abundant sunlight in China. To gather and analyze the serum VD levels of healthy children in Hainan, so as to understand their VD nutritional status and improve the representative data of VD nutritional status in south China.

METHODS

Children who presented to the outpatient clinic for physical examination at 4 hospitals in the Hainan Province from 2012 to 2020 were enrolled in this study. The serum 25-hydroxyvitamin D (25-OHD) levels was analyzed. 25-OHD levels <50 nmol/L is considered VDD, 50-75 nmol/L is vitamin D insufficiency (VDI), and ≥75 nmol/L is VD sufficient (VDS).

RESULTS

The average serum 25-OHD level was 94.63±49.99 nmol/L [95% confidence interval (CI): 93.67-95.60]. VDD was detected in 13.98% of participants (1,435 cases), VDI was detected in 30.60% of participants (3,140 cases), and 55.42% presented with VDS (5,687 cases). The average 25-OHD level of boys was significantly higher than that of girls (t=3.67, P<0.001). The average serum 25-OHD levels in the following age groups 0-1, 1-3, 3-7, 7-14, and 14-18 years were 105.92±57.39, 100.55±53.22, 86.35±39.19, 73.61±34.21, and 54.97±19.19 nmol/L, respectively. These results suggested that with an increase in age, the 25-OHD levels decreased. The average 25-OHD levels of children with a body mass index (BMI) <85^th percentile were significantly higher than that of children in the overweight and obese group (F=7.393, P=0.001).

CONCLUSIONS

A certain proportion of all age groups showed vitamin D deficiency and insufficiency in Hainan. A formal recommendation for vitamin D supplementation should be considered, especially in autumn and winter seasons for children over 7 years old, and in those with BMI ≥85^th percentile or BMI ≥95^th percentile.

Knowledge and practice of mothers towards sunshine exposure of their children in Ethiopia: a systematic review and meta-analysis

BACKGROUND

Early morning sunlight exposure for infants is a good practice to prevent rickets and alleviate the problem of vitamin D deficiency. Rickets is a major public health problem in many countries especially in developing country including Ethiopia. As mothers are frontline person for their children who should know and practice about sunlight exposure, this systematic review and meta-analysis aimed to assess the pooled level of knowledge and practice towards sunlight exposure of their children among mothers in Ethiopia.

METHODS

PubMed, Google Scholar, Excerpta Medica database (EMBASE), Cochrane Library, Web of Science, and African Journal of Online (AJOL) were searched. The data were extracted using Microsoft Excel and analyzed using STATA version 14. Publication bias was checked by funnel plot and more objectively through Egger's regression test, with P < 0.05 considered to indicate potential publication bias. The heterogeneity of studies was checked using I² statistics. Pooled analysis was conducted using a weighted inverse variance random-effects model. Subgroup analysis was done related to geographic region and time. A leave-one-out sensitivity analysis was also employed.

RESULT

A total of 8 studies with 2974 study participants for knowledge, nine studies with 3475 study participants for practice were used to estimate the pooled level of good knowledge and good practice of sunshine exposure among Ethiopian mothers. The overall estimated good level of knowledge and good practice towards sunshine exposure of their children among mothers was found to be 56.08% ((95% CI: 46.26 - 65.89%; I2 = 96.8%) and 55.632% (95%CI: 44.091 - 67.174%; I2 = 98.2%). Regional subgroup analysis showed that the pooled level of good practice in Amhara and Sidama regions found to be 54.41 and 58.32% respectively.

CONCLUSION

Study findings showed mothers knowledge and practice towards sunshine exposure of children was quite low in Ethiopia. This study therefore recommends that interventions are needed to increase knowledge and practice of sunlight exposure. This study provides much needed significant evidence for making health-policy recommendations for this vulnerable population group.

Prevalence and Determinants of Vitamin D Deficiency in 1825 Cape Town Primary Schoolchildren: A Cross-Sectional Study

Vitamin D deficiency (25-hydroxyvitamin D[25(OH)D] <50 nmol/L) is common among adults in Cape Town, South Africa, but studies investigating vitamin D status of children in this setting are lacking. We conducted a cross-sectional study to determine the prevalence and determinants of vitamin D deficiency in 1825 Cape Town schoolchildren aged 6−11 years. Prevalence of vitamin D deficiency was 7.6% (95% Confidence Interval [CI] 6.5% to 8.9%). Determinants of vitamin D deficiency included month of sampling (adjusted odds ratio [aOR] for July−September vs. January−March 10.69, 95% CI 5.02 to 22.77; aOR for October−December vs. January−March 6.73, 95% CI 2.82 to 16.08), older age (aOR 1.25 per increasing year, 95% CI: 1.01−1.53) and higher body mass index (BMI; aOR 1.24 per unit increase in BMI-for-age Z-score, 95% CI: 1.03−1.49). In a subset of 370 participants in whom parathyroid hormone (PTH) concentrations were measured; these were inversely related to serum 25(OH)D concentrations (p < 0.001). However, no association between participants with hyperparathyroidism (PTH >6.9 pmol/L) and vitamin D deficiency was seen (p = 0.42). In conclusion, we report that season is the major determinant of vitamin D status among Cape Town primary schoolchildren, with prevalence of vitamin D deficiency ranging from 1.4% in January−March to 22.8% in July−September.

Prevalence of vitamin D deficiency and its associated risk factors among rural population of the northern part of the Persian Gulf

BACKGROUND

Accumulating evidence indicates that vitamin D deficiency has been increased globally over the last two decades. However, the majority of these studies are concerned with cities and there is scant information regarding the prevalence of vitamin D in rural areas. The main aim of this study was to investigate the prevalence of vitamin D deficiency and its associated risk factors among the rural population in Bushehr province which shares the longest border with the Persian Gulf.

METHODS

The rural inhabitants of more than 25 years old from three mountainous, plain, and seashore areas of Bushehr province were selected through a stratified multi-cluster random sampling method. After obtaining the participants' demographic and anthropometric data and their past medical history, serum 25-hydroxyvitamin D [25(OH)D] was measured using ELISA.

RESULTS

A total of 1806 (means ±SD, 46± 14years old) rural subjects (35 % males and 65 % females) participated in this study. The prevalence of vitamin D deficiency, insufficiency, and sufficiency were 28 %, 50 %, and 22 %, respectively. The deficiency of vitamin D in women was higher than in men (OR=1.27, 95 % CI: 1.05 to 1.54, P=0.04). There was a positive significant correlation between age and serum vitamin D levels. Men with vitamin D deficiency had higher BMI (P=0.008); this association was not observed among women (P=0.7). There was no significant difference between the food item's consumption frequencies, and vitamin D status (P>0.05). The mountainous, and plain areas had the highest and lowest vitamin D levels, respectively.

CONCLUSIONS

Although, Bushehr province is located in a sunny part of Iran, the prevalence of vitamin D deficiency was high among its rural population. The shift of their lifestyle patterns and rapid industrialization in these rural areas may be responsible. Therefore, the enrichment of dietary sources with vitamin D and the use of vitamin D supplements are recommended to tackle the high prevalence of vitamin D deficiency in the rural population of the northern part of the Persian Gulf.

Prevalence and predictors of vitamin D deficiency in young African children

BACKGROUND

Children living in sub-Saharan Africa have a high burden of rickets and infectious diseases, conditions that are linked to vitamin D deficiency. However, data on the vitamin D status of young African children and its environmental and genetic predictors are limited. We aimed to examine the prevalence and predictors of vitamin D deficiency in young African children.

METHODS

We measured 25-hydroxyvitamin D (25(OH)D) and typed the single nucleotide polymorphisms, rs4588 and rs7041, in the GC gene encoding the vitamin D binding protein (DBP) in 4509 children aged 0-8 years living in Kenya, Uganda, Burkina Faso, The Gambia and South Africa. We evaluated associations between vitamin D status and country, age, sex, season, anthropometric indices, inflammation, malaria and DBP haplotypes in regression analyses.

RESULTS

Median age was 23.9 months (interquartile range [IQR] 12.3, 35.9). Prevalence of vitamin D deficiency using 25(OH)D cut-offs of < 30 nmol/L and < 50 nmol/L was 0.6% (95% CI 0.4, 0.9) and 7.8% (95% CI 7.0, 8.5), respectively. Overall median 25(OH)D level was 77.6 nmol/L (IQR 63.6, 94.2). 25(OH)D levels were lower in South Africa, in older children, during winter or the long rains, and in those with afebrile malaria, and higher in children with inflammation. 25(OH)D levels did not vary by stunting, wasting or underweight in adjusted regression models. The distribution of Gc variants was Gc1f 83.3%, Gc1s 8.5% and Gc2 8.2% overall and varied by country. Individuals carrying the Gc2 variant had lower median 25(OH)D levels (72.4 nmol/L (IQR 59.4, 86.5) than those carrying the Gc1f (77.3 nmol/L (IQR 63.5, 92.8)) or Gc1s (78.9 nmol/L (IQR 63.8, 95.5)) variants.

CONCLUSIONS

Approximately 0.6% and 7.8% of young African children were vitamin D deficient as defined by 25(OH)D levels < 30 nmol/L and < 50 nmol/L, respectively. Latitude, age, season, and prevalence of inflammation and malaria should be considered in strategies to assess and manage vitamin D deficiency in young children living in Africa.

Sun exposure as a strategy for acquiring vitamin D in developing countries of tropical region: Challenges & way forward

Adopting sun exposure as a low-cost sustainable strategy in tropical countries needs critical analysis for its feasibility and inclusion in national policy. This review explores the opportunities and challenges associated with sun exposure in tropical countries and discusses potential strategies that may be adopted for promoting sun exposure. For this, two strands of evidence were reviewed; trials on sun exposure, analysed for risk of bias and, the environmental factors that influence acquisition of vitamin D from sun exposure in the context of on-going ecological and nutritional transition. Compilation of data from available databases in terms of deficiency, per cent rural population, status of fortification, air pollution, ultraviolet index, skin reflectance and skin cancer prevalence were done. In the context of environmental and lifestyle-related challenges, opportunities go hand-in-hand in terms of built environment, variability in air pollution and personal factors such as skin pigmentation, precursor availability and general nutritional status. Contextual policy decisions should consider urban and rural development planning, control of air pollution, targeted guidelines for indigenous and immigrant population and use of space technology in educating general population for balanced sun exposure as essential components for a sustainable strategy. Important opportunities exist for tropical countries to develop sun exposure as a strategy for acquiring vitamin D and these need to be explored.

The impact of vitamin D food fortification and health outcomes in children: a systematic review and meta-regression

OBJECTIVE

Vitamin D (vitD) deficiency is a global childhood health problem. Food fortification is a promising strategy to curb vitD deficiency. We aimed to assess the effectiveness of utilizing vitD fortification in staple foods to improve 25hydroxyvitamin D (25(OH)D) concentration and to reduce the prevalence of vitD deficiency among healthy children.

METHODS

We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) evaluating the use of vitD fortified food products compared to no fortification among healthy children aged 1-18 years old. We searched Medline, Embase, Global Health, and Cochrane (CENTRAL) databases from database inception until May 2019. Independently, six reviewers in pairs screened titles and abstracts, assessed the full text for eligibility, and performed data extraction and quality assessment. The primary outcome is the impact of fortification on 25(OH)D concentration. The secondary outcomes included the impact of fortification on the prevalence of vitD deficiency, school performance, cognitive function, school absences, infection rate, hospital admission length, and compliance with fortified food product consumption.

RESULTS

We identified 2229 articles. After assessing eligibility, 20 RCTs met the inclusion criteria. The eligible RCTs assessed the fortification of milk, cereal, juice, bread, yogurt, and cheese compared with no fortification. All RCTs, except for three, had a low risk of bias. Food fortification improved 25(OH)D concentration by a mean difference (MD) of 15.51 nmol/L (95% confidence interval (CI) 6.28, 24.74; I² = 99%), which resulted in a mean increase of 3 nmol/l for every 100 IU of vitD, when adjusted for baseline 25(OH)D concentration and country latitude. Additionally, the prevalence of vitD deficiency decreased by a risk ratio of 0.53 (95% CI 0.41, 0.69; I² = 95%), and cognitive function improved by a MD of 1.22 intelligence quotient (IQ) points (95% CI 0.65, 1.79; I² = 0%). The overall evidence quality was high.

CONCLUSION

VitD food fortification is an effective way to improve 25(OH)D concentration, prevent vitD deficiency, and improve IQ levels.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42017057631.

Sunlight exposed body surface area is associated with serum 25-hydroxyvitamin D (25(OH)D) level in pregnant Minangkabau women, Indonesia

BACKGROUND

Vitamin D deficiency is highly prevalent in women, and living in a tropical country with a year-round abundance of sunlight as the primary source of vitamin D does not seem to guarantee adequate serum 25(OH)D. While living in the tropics, Minangkabau women are known to dress specifically according to their culture. This study was aimed to elucidate the association of sunlight exposed body surface area with serum 25(OH)D in pregnant Minangkabau women of Indonesia.

METHODS

We performed a cross-sectional study on 88 Minangkabau women in late pregnancy. Lifestyle data were collected using a questionnaire, and dietary intake of vitamin D was calculated from 24-h food recall. The skin pigmentation type was determined by the Fitzpatrick scale, and the body surface area exposed to sunlight was estimated. Serum 25(OH)D was quantified by ELISA method. Serum 25(OH)D differences according to the duration of sunlight exposure, skin pigmentation type, and sunscreen use were statistically analyzed by ANOVA. The correlation of sunlight exposed body surface area and serum 25(OH)D was analyzed by Spearman's correlation.

RESULTS

Nearly half of the subjects (n = 40; 45.5%) were deficient in vitamin D (< 20 ng/ml) with serum 25(OH)D level 23.0 ± 10.0 ng/ml (mean ± SD) and the estimated daily intake of vitamin D was 5.6 ± 3.9 μg/1000 kcal/day (mean ± SD). The median percentage of body area exposed to sunlight was 15.8%. There were no differences in serum 25(OH)D levels according to sunlight exposure time, skin pigmentation type, and sunscreen use. The percentage of body area exposed to sunlight was positively correlated with serum 25(OH)D level (Spearman's ρ = 0.403; p < 0.001).

CONCLUSIONS

Vitamin D deficiency is prevalent in pregnant Minangkabau women. Since increasing body surface area exposed to sunlight may not be culturally acceptable, vitamin D supplementation needs to be considered in this population.

Higher risk of vitamin D insufficiency/deficiency for rural than urban dwellers

There are many risk factors for Vitamin D deficiency. This study aimed to compare the Vitamin D status and serum 25(OH)D concentrations of adults living in an urban area to adults living in a rural area in the West of Ireland (latitude 53.27° North). A cross-sectional retrospective analysis of clinical records was performed. Following interrogation of the electronic laboratory information system, individuals who had serum 25(OH)D concentrations measured at Galway University Hospitals between January 2011 and December 2015 were identified. Clinical demographics, setting and date of sampling were recorded. In total, 17,590 patients (urban n = 4,824; rural n = 12,766) were eligible for inclusion. Serum 25(OH)D concentrations were lower among rural compared to urban dwellers irrespective of season (spring p < 0.001, summer p = 0.009, autumn p = 0.002, winter p < 0.001). There was a significant difference in Vitamin D status between urban and rural dwellers in three of the four seasons: spring- deficiency: 16%-v-23%, insufficiency: 39%-v-43%, sufficiency: 45%-v-35% (p < 0.001); autumn- deficiency: 11%-v-10%, insufficiency: 30%-v-35%, sufficiency: 59%-v-56% (p = 0.01); winter- deficiency: 23%-v-25%, insufficiency: 35%-v-42%, sufficiency: 41%-v-33% (p < 0.001). Serum 25(OH)D concentrations were higher and the prevalence of deficiency lower in urban/rural females compared to urban/rural males (p < 0.001). Serum 25(OH)D concentrations increased sequentially from the 18-39 year age group to the 60-69 year age group in both urban (p < 0.001) and rural (p < 0.001) dwellers and then decreased progressively as age increased to ≥90 years. The odds of Vitamin D deficiency increased with age, lower daily sunshine hours, male gender, rural address and season.

Validation of the CIMI-Ethiopia Program and Seasonal Variation in Maternal Nutrient Intake in Enset (False Banana) Growing Areas of Southern Ethiopia

BACKGROUND

Tools for the rapid and accurate analysis of nutrient intakes from diets of individuals in Southern Ethiopia are lacking. The Calculator of Inadequate Micronutrient Intake program for Ethiopia (CIMI-Ethiopia) has been developed to overcome this problem. CIMI-Ethiopia also computes protein and energy intakes from the diet. The objectives of the current study were to validate CIMI-Ethiopia for the dietary pattern of Southern Ethiopia, and assess the nutrient intakes in postharvest dry and lean wet seasons.

METHODS

24-h dietary recall (24HR) data was collected from 578 women of a reproductive age in postharvest dry and lean wet seasons in 2017. For analysis, 24HR data was entered into NutriSurvey (NS), which was the reference nutrition software, and then into CIMI-Ethiopia. For validation, the mean and standard deviation (SD) of the difference between CIMI-Ethiopia and NS were computed. The percentage of participants with an inadequate intake was calculated. The correlation between CIMI-Ethiopia and NS results was determined. The nutrient intakes in postharvest dry and lean seasons were compared.

RESULTS

Among the nutrients, pantothenic acid, vitamin B1, and protein showed a very high accuracy in CIMI-Ethiopia calculation (|difference (D)| < 5.0% of the NS result). Nutrients with a good accuracy (|D| = 5%-15%) were iron, zinc, magnesium, vitamin B12, vitamin B6, and energy. The accuracy for calcium, niacin, and vitamin A was moderate (|D| = 15%-30%). The intakes calculated by CIMI-Ethiopia and NS of iron, zinc, magnesium, calcium, B-complex vitamins, vitamin A, protein, and energy were highly correlated (r = 0.85-0.97, p < 0.001). NS analysis identified a significant reduction in the mean intake of iron; zinc; magnesium; pantothenic acid; vitamin B1, B12, and D; protein; and energy in the lean wet season; however, calcium and vitamin A intake increased.

CONCLUSIONS

It has been found that CIMI-Ethiopia is a valid tool for estimating nutrient intakes at an individual level in Southern Ethiopia. The study demonstrated a decline in intakes of iron; zinc; magnesium; pantothenic acid; vitamin B1, B12, and D; protein; and energy in the lean wet season. This result provides some hint for fortification and supplementation programs that aim to combat maternal malnutrition in rural Southern Ethiopia.

Vitamin D Deficiency is Associated with Increased Use of Antimicrobials among Preschool Girls in Ethiopia

Preschool children in Addis Ababa, Ethiopia, are highly exposed to influenza viruses. Factors related to infections, nutrition, and environmental conditions that might explain the burden of influenza among these children were investigated. Ninety-five preschool children, 48 girls and 47 boys, were followed clinically for 12 months. Illness and immune responses to influenza; three other respiratory viruses; five airway pathogenic bacteria; and levels of vitamins D, A, and B12 were assessed. Most of the children had antibodies to numerous respiratory viral and bacterial agents at study start, and many were infected during follow-up. Twenty-five girls and 25 boys fell ill during the study, and were treated with one or more courses of systemic antimicrobials. Ninety percent of both girls and boys had 25-hydroxyvitamin D [25(OH)D] levels below the recommended levels. While there was no overall difference in the levels of vitamins D, A, and B12 between girls and boys, treated girls had significantly lower 25(OH)D levels than non-treated girls and treated boys. There was a considerable number of short for age children, but only the short treated girls had significantly lower 25(OH)D levels than the non-treated children. Preschool girls with low 25(OH)D levels were more vulnerable to pathogenic microbes than boys.

Vitamin D Status and Association of VDR Genetic Polymorphism to Risk of Breast Cancer in Ethiopia

Emerging evidence associates vitamin D deficiency and vitamin D receptor (VDR) genetic variations with risk for breast cancer. This study investigated the prevalence of vitamin D deficiency and its association with tumor characteristics and the implications of VDR genetic variations for risk of breast cancer in Ethiopia. This unmatched case–control study involved 392 female breast cancer patients and 193 controls. The plasma 25-hydroxyvitamin D (25(OH)D₃) level was quantified in chemotherapy-naïve (N = 112) and tamoxifen-treated patients (N = 89). Genotyping for the VDR common variant alleles rs7975232 (ApaI), rs2228570 (FokI), and rs731236 (TaqI) was done. Eighty-six percent of the patients were vitamin D deficient (<50 nmol/L). Chemotherapy-naïve breast cancer patients had a higher prevalence of vitamin D deficiency (91.9% vs. 78.3%) compared to the tamoxifen-treated group (p < 0.001). The prevalence of severe vitamin D deficiency (<25 nmol/L) was significantly higher in chemotherapy-naïve (41.1%) than tamoxifen-treated (11.2%) patients. Vitamin D deficiency was not significantly associated with tumor characteristics or VDR genotype. The rs2228570 GG genotype was associated with increased risk of breast cancer (OR = 1.44, 95% confidence interval = 1.01−2.06). Our result indicates that rs2228570 might be a moderate risk factor for breast cancer development in the Ethiopian population. The high prevalence of severe vitamin D deficiency in treatment-naïve breast cancer patients indicates the need for nutritional supplementation of vitamin D at the time of chemotherapy initiation.

Vitamin D Deficiency among Patients with Tuberculosis: a Cross-Sectional Study in Iranian-Azari Population

BACKGROUND

Vitamin D deficiency or insufficiency has been conducted with increased risk for tuberculosis (TB). Despite this association, discrepancies exist among different studies in different regions. The aim of this study was to evaluate the prevalence of vitamin D deficiency and its predictors in tuberculosis among the Iranian-Azari population.

MATERIALS AND METHODS

A total of 60 participants were enrolled in this study, 30 of which were newly diagnosed TB patients and 30 were healthy volunteers. At least two serum samples were collected, the first sample before the start of anti-TB treatment and the second sample 3 months after the effective treatment.

RESULTS

The prevalence of vitamin D deficiency (25 patients vs. 2 healthy individuals; P<0.001) and serum levels of the vitamin D (22.66±15.17 vs. 73.03±25.6 ng/mL; P<0.001) were significantly higher in patients with TB than healthy subjects. Likewise, the prevalence of vitamin D deficiency in the extrapulmonary TB group was higher than that of the pulmonary TB, but this difference was not statistically significant (P=0 .397). Moreover, there was no significant difference between mean levels of vitamin D in patients with tuberculosis before and after treatment (P = 0.787). Linear regression analysis showed there was no significant relationship between vitamin D levels after treatment and age, gender, body site of tuberculosis, and vitamin D levels before treatment, P≥0.68.

CONCLUSION

Vitamin D deficiency is higher in patients with tuberculosis than healthy individuals.

Age and gender differences in the prevalence and correlates of vitamin D deficiency

Younger adults and males had a higher prevalence of vitamin D deficiency compared to older participants and females. Low intake of milk, central obesity, and lack of use of vitamin D supplements were associated with vitamin D deficiency, highlighting potentially important avenues for preventive intervention.

BACKGROUND

Vitamin D deficiency is a public health concern. This study's objective was to measure the prevalence of vitamin D deficiency and determine its correlates among Saudi adults in Riyadh, Saudi Arabia.

METHODS

A cross-sectional study was conducted with 2835 Saudi males and females aged 30-75 years in 18 different primary health care centers (PHCC) in Riyadh. Detailed interviews on sociodemographic and lifestyle factors and anthropometric measurements were conducted. Serum calcium, phosphorus, parathyroid, alkaline phosphatase, and 25(OH) vitamin D were measured. Multiple logistic regression analyses were conducted.

RESULTS

The mean age (SD) of male and female participants was 43.0 (± 11.7) and 42.8 (± 10.3) years, respectively. Serum 25(OH) vitamin D assays for participants revealed that 72.0% (n = 695) of males and 64.0% (n = 1191) of females had levels < 50 nmol/L (deficiency), whereas 17.3% (n = 166) and 19.4% (n = 362), respectively, had levels of 50-75 nmol/L (insufficiency). Multivariate analyses for males revealed that lack of use of vitamin D supplements [adjusted odds ratio (aOR) = 4.0, 95% CI 1.7, 9.4], younger age [30-40 years aOR = 3.6, 95% CI 1.7, 7.3 and 41-50 years aOR = 4.2, 95% CI 2.0, 8.8], low milk intake [aOR = 1.7, 95% CI 1.0, 2.8], consumption of cola drinks [aOR = 2.0, 95% CI 1.1, 3.9], and central obesity [aOR = 1.8, 95% CI 1.0, 3.4] were associated with low vitamin D. In females, lack of use of vitamin D supplements [aOR = 3.7, 95% CI 2.8, 4.9], younger age [30-40 years aOR = 3.4, 95% CI 2.0, 5.8 and 41-50 years aOR = 2.8, 95% CI 1.6, 4.7], central obesity [aOR = 1.4, 95% CI 1.0, 2.2], and seasonal variation [aOR = 1.6, 95% CI 1.3, 2.1] had higher odds for vitamin D deficiency. Significantly lower levels were observed for men than women for mean serum 25(OH) vitamin D [42.6 (± 24.1) vs. 46.8 (± 30.5)], parathyroid hormone [5.3 (± 2.9) vs. 5.9 (± 2.7)], and phosphorus [1.1 (± 0.2) vs. 1.2 (± 0.2)], respectively; alkaline phosphatase levels [106 (± 32.8) vs. 99 (± 27.8)] [p < 0.01] were significantly higher in males than females.

CONCLUSION

Vitamin D deficiency was highly prevalent, particularly among young adults and those with central obesity. Proper fortification policy, health education, and regular screening PHCCs may help prevent and treat vitamin D deficiency.

Determinants of Vitamin D Status in Indian School-children

INTRODUCTION

Due to the high prevalence of Vitamin D deficiency in spite of abundant sunshine and scarcity of studies investigating Vitamin D status in Indian children from rural and semirural areas, the objectives of this cross-sectional study were to: (1) assess the Vitamin D status of school-children in a semi-rural setting and (2) identify the determinants of Vitamin D status in these children.

MATERIALS AND METHODS

Data collected included anthropometric measurements (height and weight), body composition, three-one-day dietary recall method, demographic data, and sunlight exposure. Serum 25-hydroxyVitamin D (25(OH)D) was estimated by enzyme-linked immunosorbent assay (ELISA) technique. SPSS software was used for statistical analysis.

RESULTS

Anthropometric characteristics of the children were similar and mean serum 25(OH)D concentration was 58.5 ± 10.3 nmol/L with no significant differences between genders. Around 80% children reported sunlight exposure of 2 h or more. A majority (71%) of children were Vitamin D insufficient with serum 25(OH)D concentrations between 50 and 74.9 nmol/L. Determinants of Vitamin D identified were duration of sunlight exposure and body fat percent. Significant (P < 0.05) positive association of duration of sunlight exposure was observed with serum 25(OH)D concentrations, while BF% showed a negative association with serum 25(OH)D (β = -0.307; standard error = 0.1388; P < 0.05).

DISCUSSION

We have reported a high prevalence of Vitamin D insufficiency in school-children aged 6-12 years, from a semirural setting, in spite of a majority (80%) reporting >2 h of sunlight exposure. We have also demonstrated that duration of sunlight exposure and body fat percentage are the two important determinants of serum 25(OH)D concentrations in these children.

Current Evidence on Vitamin D Deficiency and Metabolic Syndrome in Obese Children: What Does the Evidence from Saudi Arabia Tell Us?

Obesity and vitamin D deficiency represent major health problems among Saudi children, and have been linked to chronic diseases. Obese children are at risk of developing vitamin D deficiency, which appears to have negative influences on energy homeostasis, impeded bone mineralisation, insulin resistance and inflammation. Evidence supporting the association between vitamin D deficiency of obese children and metabolic syndrome has not specifically been studied in early childhood. The mechanisms through which vitamin D deficiency is associated with metabolic syndrome in obese children needs further elucidation. This commentary aims to (i) summarise current knowledge of the association between vitamin D deficiency and metabolic syndrome in obese children; and (ii) discuss current evidence for the association among Saudi Arabian children.

CRP Genotypes Predict Increased Risk to Co-Present with Low Vitamin D and Elevated CRP in a Group of Healthy Black South African Women

Low 25-hydroxyvitamin D (25(OH)D) and elevated C-reactive protein (CRP) concentrations are independently associated with adverse health outcomes, including cardiovascular disease (CVD). Although an inverse association between these factors has been described, the underlying mechanisms remain unknown. We postulate that environment-gene interactions, through which 25(OH)D interacts with single nucleotide polymorphisms (SNPs) within the CRP gene, modulate CRP; that certain CRP genotypes predispose individuals to a co-phenotype of low 25(OH)D and elevated CRP concentrations; and that this co-phenotype is associated with higher CVD risk. Twelve CRP SNPs were genotyped, and both 25(OH)D and CRP were quantified, in 505 black South African women. Alarmingly, 66% and 60% of the women presented with deficient/insufficient 25(OH)D and elevated CRP concentrations, respectively. CRP concentrations were higher in individuals with lower 25(OH)D concentrations. However, no 25(OH)D-CRP genotype interactions were evident. Several genotypes were associated with an altered risk of presenting with the co-phenotype, indicating a genetic predisposition. Women presenting with this co-phenotype had higher blood pressure and increased anthropometric measures, which may predispose them to develop CVD. We recommend increasing vitamin D fortification and supplementation efforts to reduce inflammation among black women with vitamin D deficiency, thereby possibly curbing diseases contingent on the co-phenotype described here.

Rickets

Rickets is a bone disease associated with abnormal serum calcium and phosphate levels. The clinical presentation is heterogeneous and depends on the age of onset and pathogenesis but includes bowing deformities of the legs, short stature and widening of joints. The disorder can be caused by nutritional deficiencies or genetic defects. Mutations in genes encoding proteins involved in vitamin D metabolism or action, fibroblast growth factor 23 (FGF23) production or degradation, renal phosphate handling or bone mineralization have been identified. The prevalence of nutritional rickets has substantially declined compared with the prevalence 200 years ago, but the condition has been re-emerging even in some well-resourced countries; prematurely born infants or breastfed infants who have dark skin types are particularly at risk. Diagnosis is usually established by medical history, physical examination, biochemical tests and radiography. Prevention is possible only for nutritional rickets and includes supplementation or food fortification with calcium and vitamin D either alone or in combination with sunlight exposure. Treatment of typical nutritional rickets includes calcium and/or vitamin D supplementation, although instances infrequently occur in which phosphate repletion may be necessary. Management of heritable types of rickets associated with defects in vitamin D metabolism or activation involves the administration of vitamin D metabolites. Oral phosphate supplementation is usually indicated for FGF23-independent phosphopenic rickets, whereas the conventional treatment of FGF23-dependent types of rickets includes a combination of phosphate and activated vitamin D; an anti-FGF23 antibody has shown promising results and is under further study.

Serum Vitamin D Level Associates With Handgrip Muscle Strength Among Ethiopian Schoolchildren: A Cross-Sectional Study

BACKGROUND

Despite varying serum levels of 25(OH)D among schoolchildren in Ethiopia, data are lacking whether this affects their muscle function as measured by handgrip strength of these children. Handgrip strength may be used as a proxy indicator of muscle strength and function. This study evaluated the association between serum levels of 25(OH)D and handgrip strength among schoolchildren in Ethiopia.

METHODS

The study used a data set from a school-based cross-sectional study conducted on a total of 174 randomly selected schoolchildren from urban (N = 89) and rural (N = 85) settings of Adama Town and Adama Woreda, respectively. Handgrip strength, serum 25(OH)D levels, and anthropometry were measured for each child following standard procedures, while data on demographic characteristics of children and their parents were collected using a structured interviewer-administered questionnaire. A multivariable linear regression model was used to determine the association between serum vitamin D level and handgrip strength after adjusting for other predictors.

RESULTS

The mean handgrip muscle strength of the students was 17.6 ± 6.9 kg. The average serum 25(OH)D for the group was 54.5 ± 15.8 nmol/L. On multivariable linear regression model, serum 25(OH)D level was significantly associated with handgrip strength (β = 0.06, P = .008) of the children after controlling for potential confounders. Other variables, female gender (β = -2.20, P = .004), age (β = 1.97, P < .001), height (β = .22, P < .001), weight (β = 0.33, P < .001), and triceps skinfold thickness (β = -0.19, P = .023), were identified to have significant association with handgrip strength of schoolchildren.

CONCLUSION

Serum 25(OH)D levels had significant positive association with handgrip strength of Ethiopian schoolchildren. The results imply the need for incorporating school nutrition education on consumption of foods rich in important nutrients including vitamin D-rich foods in the school curricula and also enhancing behavioral change communication toward exposure to sunlight in the school to produce adequate vitamin D. Further longitudinal study involving a larger sample is recommended to confirm the findings.

Vitamin D deficiency among smear positive pulmonary tuberculosis patients and their tuberculosis negative household contacts in Northwest Ethiopia: a case-control study

Background

Vitamin D is a fat-soluble vitamin that increases the immunity against tuberculosis (TB), decreases the re-activation of latent TB and reduces the severity of active TB disease. Epidemiological studies on the prevalence of vitamin D deficiency, and its association with TB showed inconsistent results in different countries. This study was aimed to determine the prevalence of vitamin D deficiency and its association with TB in Northwest Ethiopia.

Methods

A case–control study was conducted among smear positive pulmonary tuberculosis patients and their household contacts without symptoms suggestive of TB. Study participants were recruited at 11 TB diagnostic health facilities in North and South Gondar zones of Amhara region between May 2013 and April 2015. The spot-morning-spot sputum samples and 5 ml blood sample were collected prior to commencing TB treatment for the diagnosis of TB and serum vitamin D assay, respectively. The diagnosis of TB was performed using smear microscopy and GeneXpert. Serum vitamin D level was analyzed using VIDAS 25 OH Vitamin D Total testing kits (Biomerieux, Marcy I’Etoile, France) on mini VIDAS automated immunoassay platform. Vitamin D status was interpreted as deficient (<20 ng/ml), insufficient (20–29 ng/ml), sufficient (30–100 ng/ml) and potential toxicity (>100 ng/ml).

Results

Of the total study participants, 134 (46.2%) were vitamin D deficient, and only 56 (19.3%) had sufficient vitamin D level. A total of 59 (61.5%) TB patients and 75 (38.7%) non TB controls were vitamin D deficient. Results of multivariate logistic regression analyses showed a significantly higher vitamin D deficiency among tuberculosis cases (p < 0.001), females (p = 0.002), and urban residents (p < 0.001) than their respective comparison groups. Moreover, age groups of 35–44 (p = 0.001), 45–54 (p = 0.003) and ≥55 (p = 0.001) years had significantly higher vitamin D deficiency compared with age group <15 years.

Conclusions

Vitamin D deficiency is highly prevalent among TB patients and non TB controls in Ethiopia where there is year round abundant sunshine. Study participants with tuberculosis, females, older age groups, and urban residents had significantly higher prevalence of vitamin D deficiency. These findings warrant further studies to investigate the role of vitamin D supplementation in the prevention and treatment of tuberculosis in high TB burden countries like Ethiopia.

Nutritional rickets around the world: an update

Worldwide, nutritional rickets continues to be an evolving problem with several causes. This paper provides an updated literature review characterising the prevalence, aetiology, pathophysiology and treatment of nutritional rickets worldwide. A systematic review of articles on nutritional rickets from various geographical regions was undertaken. For each region, key information was extracted, including prevalence, cause of rickets specific to the region, methods of confirming the diagnosis and current treatment and preventive measures. Calcium deficiency continues to be a major cause of rickets in Africa and Asia. Vitamin D deficiency rickets is perhaps increasing in the Americas, Europe and parts of the Middle East. There continues to be a distinct presentation of calcium-predominant versus vitamin D predominant rickets, although there are overlapping features. More careful diagnosis of rickets and reporting of 25-OHD concentrations has improved accurate knowledge of rickets prevalence and better delineated the cause. Nutritional rickets continues to be an evolving and multi-factorial problem worldwide. It is on a spectrum, ranging from isolated vitamin D deficiency to isolated calcium deficiency. Specific areas which require emphasis include a consistent community approach to screening and diagnosis, vitamin D supplementation of infants and at-risk children, prevention of maternal vitamin D deficiency and the provision of calcium in areas with low calcium diets.

Comparisons of physical activity, adipokines, vitamin D status and dietary vitamin D intake among adolescents

BACKGROUND

Considering that lifestyle and diet are key factors responsible for the increases in adiposity in youth, it is important to understand how vitamin D, adipokines and markers of glucose metabolism are related to physical activity level (PAL) during growth. The present study aimed to investigate associations between physical activity level, adiponectin/leptin ratio, vitamin D status and dietary vitamin D intake among adolescents.

METHODS

A cross-sectional study was conducted with adolescents aged 14-18 years old who were living in São Paulo, Brazil. Serum 25 hydroxyvitamin D [25(OH)D], adiponectin (A), leptin (L), glucose and insulin were obtained after 12 h of fasting. Dietary calcium and vitamin D intake were measured by 24-h food record, as repeated in 62.6% of the sample. PAL was measured by the International Physical Activity Questionnaire (IPAQ). Pearson's chi-square test, Pearson correlation and linear regression analysis were performed.

RESULTS

A total of 198 subjects, mean (SD) age 16.3 (1.4) years, 51% male, were enrolled in the study. Some 9% of participants were sedentary, 22% were insufficiently active (IA), 51% were active and 18% were very active (VA). The A/L ratio was lower among sedentary/IA subjects [2.2 (4.0) versus 5.6 (12.3); P = 0.01] compared to active/VA subjects. PAL was not associated with vitamin D status or markers of glucose metabolism. Serum 25(OH)D positively associated with vitamin D intake, after adjusting for sex, sun exposure and season of the year in regression analysis (partial r² =0.026, P = 0.02).

CONCLUSIONS

Low PAL was associated with a lower A/L ratio. Vitamin D status was not associated with sun exposure habits, although it was positively correlated with vitamin D intake.

Association between serum levels of bioavailable vitamin D and negative symptoms in first-episode psychosis

Total vitamin D levels had been commonly reported to be lowered in patients with chronic psychotic illnesses in countries from the higher latitudes. However, studies on patients with first episode psychosis (FEP) are limited. In this study we investigated serum concentrations of total and bioavailable vitamin D levels in FEP patients compared to healthy controls and the association between symptom severity and vitamin D components. A total of 31 FEP patients and 31 healthy controls were recruited from Institute of Mental Health, Singapore. FEP patients were identified using Structured Clinical Interview for DSM-IV Axis I disorders (SCID-1) and severity symptoms were assessed using the positive and negative syndrome scale (PANSS). Sera from participants were analyzed for total vitamin D, vitamin D-binding protein (DBP) and bioavailable vitamin D. Linear regressions were performed to examine the associations between serum total and bioavailable vitamin D and the PANSS subscales. Current study noted a significantly lower bioavailable vitamin D was in the FEP group and an association between bioavailable vitamin D and negative symptoms in FEP patients in a population with a consistent supply of sun exposure throughout the year.

Prevalence and risk factors for efavirenz-based antiretroviral treatment-associated severe vitamin D deficiency: A prospective cohort study

Initiation of efavirenz-based combination antiretroviral therapy (cART) is associated with Vitamin D deficiency, but the risk factors including efavirenz pharmacokinetics for cART-induced severe vitamin D deficiency (SVDD) and the impact of anti-tuberculosis (TB) cotreatment are not explored. We investigated the prevalence of SVDD in HIV and TB-HIV coinfected patients and associated risk factors for treatment-induced SVDD.Treatment-naïve Ethiopian HIV patients with (n = 102) or without (n = 89) TB co-infection were enrolled prospectively and received efavirenz-based cART. In TB-HIV coinfected patients, rifampicin-based anti-TB treatment was initiated 4 or 8 weeks before starting cART. Plasma 25-hydroxyvitamin D (25 [OH]D), cholesterol and 4-beta hydroxycholesterol concentrations were measured at baseline, 4, 16, and 48 week of cART. Plasma efavirenz concentrations were determined at 4 and 16 weeks of cART.TB-HIV patients had significantly lower plasma 25 (OH)D3 levels than HIV-only patients at baseline. TB co-infection, low Karnofsky score, high viral load, and high CYP3A activity as measured by plasma 4β-hydroxycholesterol/cholesterol ratios were significant predictors of low 25 (OH)D3 levels at baseline. In HIV-only patients, initiation of efavirenz-based cART increased the prevalence of SVVD from 27% at baseline to 76%, 79%, and 43% at 4, 16, and 48 weeks of cART, respectively. The median 25 (OH)D3 levels declined from baseline by -40%, -50%, and -14% at 4, 16, and 48 weeks of cART, respectively.In TB-HIV patients, previous anti-TB therapy had no influence on 25 (OH)D3 levels, but the initiation of efavirenz-based cART increased the prevalence of SVDD from 57% at baseline to 70% and 72% at the 4 and 16 weeks of cART, respectively. Median plasma 25 (OH)D3 declined from baseline by -17% and -21% at week 4 and 16 of cART, respectively.Our results indicate low plasma cholesterol, high CYP3A activity, and high plasma efavirenz concentrations as significant predictors of early efavirenz-based cART-induced vitamin D deficiency. Low plasma 25 (OH)D3 level at baseline is associated with TB co-infection and HIV diseases progression. Initiation of efavirenz-based cART is associated with high incidence of SVDD, whereas rifampicin based anti-TB therapy co-treatment has no significant effect. Supplementary vitamin D during cART initiation may be beneficial for HIV patients regardless of TB coinfection.

Vitamin D and Autism Spectrum Disorder: A Literature Review

Low vitamin D status in early development has been hypothesised as an environmental risk factor for Autism Spectrum Disorder (ASD), given the concurrent increase in the prevalence of these two conditions, and the association of vitamin D with many ASD-associated medical conditions. Identification of vitamin D-ASD factors may provide indications for primary and secondary prevention interventions. We systematically reviewed the literature for studies on vitamin D-ASD relationship, including potential mechanistic pathways. We identified seven specific areas, including: latitude, season of conception/birth, maternal migration/ethnicity, vitamin D status of mothers and ASD patients, and vitamin D intervention to prevent and treat ASD. Due to differences in the methodological procedures and inconsistent results, drawing conclusions from the first three areas is difficult. Using a more direct measure of vitamin D status—that is, serum 25(OH)D level during pregnancy or childhood—we found growing evidence for a relationship between vitamin D and ASD. These findings are supported by convincing evidence from experimental studies investigating the mechanistic pathways. However, with few primary and secondary prevention intervention trials, this relationship cannot be determined, unless randomised placebo-controlled trials of vitamin D as a preventive or disease-modifying measure in ASD patients are available.

Vitamin D Deficiency is Associated with Overweight and/or Obesity among Schoolchildren in Central Ethiopia: A Cross-Sectional Study

Childhood and adolescent obesity is an international public health problem leading to an increased risk of adulthood obesity, mortality and morbidity. Its prevalence is increasing in low-income populations, and we hypothesized it may be associated with vitamin D deficiency. Low vitamin D status is a worldwide public health issue including in Ethiopia; however, no one has examined overweight/obesity in Ethiopian schoolchildren with regard to vitamin D status. The Analyses of a data set from a school-based cross-sectional study conducted in Adama Town (n = 89) and in rural Adama Woreda (n = 85) was carried out to determine vitamin D deficiency and its association with overweight and/or obesity. Data on a total of 174 schoolchildren aged 11-18 years was used for these analyses. The overall prevalence of overweight and/or obesity was 10.3%, with 8.5% overweight and 2.3% obese; the prevalence of underweight was 19%. In the multivariable logistic regression model, vitamin D deficiency, being in the higher age group, female sex and urban residence of students, their mothers' occupation of being employed and their households' high and middle socioeconomic status were significantly associated with overweight and/or obesity. We concluded that vitamin D deficiency is an independent predictor significantly associated with overweight and/or obesity among schoolchildren from rural and urban settings in Ethiopia. The results imply the need for behavior change communications on the importance of exposure to sunlight to produce adequate vitamin D to curb this emerging health problem of overweight/obesity following economic growth and globalization in Ethiopia. As this study only highlighted the association, prospective studies and randomized controlled trials are required to establish causality.

Predictors of Serum 25-Hydroxyvitamin D Concentrations among a Sample of Egyptian Schoolchildren

Objective. To assess the level of 25-hydroxyvitamin D status among a sample of Egyptian schoolchildren and to evaluate predictors of deficiency and insufficiency. Subjects and Methods. A cross-sectional study comprising 200 prepubescent schoolchildren aged from 9 to 11 years was performed. A questionnaire including frequency of midday sun exposure, milk intake, physical activity, and level of maternal education was taken. Body mass index (BMI) was calculated; serum 25-hydroxyvitamin D [25(OH)D], serum calcium, phosphorus, and parathyroid hormone were measured. Results. Vitamin D deficiency [serum 25(OH)D < 20 ng/mL] was detected in 11.5% of subjects while its insufficiency (serum 25(OH)D is between 20 and 29.9 ng/mL) was detected in 15%. Results revealed that obesity, low physical activity, low sun exposure, and low maternal education level are significant predictors of insufficiency, though female gender, low maternal education level, and low milk intake are significant predictors of deficiency. Lower serum phosphorus and higher serum parathyroid hormone were significantly associated with both deficiency and insufficiency (p < 0.05). Conclusion. Vitamin D deficiency and insufficiency are common among schoolchildren in Egypt. Food fortification, vitamin D supplementation, and increasing maternal awareness about the importance of physical activity and exposure of their children to ultraviolet light may help to overcome this problem.

Vitamin D deficiency and its characteristics among patients with acute stroke at a national referral hospital in Kampala Uganda

BACKGROUND

Vitamin D deficiency has been associated with acute stroke and other cardiovascular diseases in the developed world. Low 25-hydroxyvitamin D (25OHD) has been described in some populations in Sub-Saharan Africa (SSA) in spite of adequate sunshine all year round. There is no information on the magnitude of vitamin D deficiency among patients with stroke and other cardiovascular diseases in Uganda or SSA. The aim of this study was to determine the burden and characteristics of vitamin D deficiency among patients with acute stroke, the most common form of cardiovascular events in SSA.

METHODS

We conducted a cross-sectional study between October 2012 and March 2013. We consecutively recruited 142 subjects with acute stroke admitted to the medical wards of Mulago hospital. We administered a pre-tested questionnaire to the study participants, and did a detailed physical examination and laboratory evaluation. Serum levels of 25OHD were determined using an electrochemiluminescence assay. Data were analyzed using STATA version 12 software.

RESULTS

The prevalence of vitamin D deficiency (25OHD < 20 ng/ml) was 15 %. Longer hours of sunshine exposure decreased the likelihood vitamin D deficiency significantly (adjusted OR 0.85, p = 0.03). Higher HDL cholesterol had a significant inverse association with vitamin D deficiency (adjusted OR 0.15, p = 0.02). In addition, the likelihood of vitamin D deficiency increased with rising age (adjusted OR 1.03, p = 0.05).

CONCLUSIONS

There was a relatively low burden of vitamin D deficiency among patients with acute stroke in Uganda. With increasing longevity and indoor lifestyles vitamin D deficiency may assume a greater role in stroke and other cardiovascular diseases in tropical sub Saharan Africa. Future studies on the mechanisms of vitamin D deficiency and its relationship to outcomes among patients with stroke may be necessary.