Deficiency of sunlight and vitamin D

Practice and factors associated with sunlight exposure of infants among mothers in Ethiopia: a systematic review and meta-analysis

BACKGROUND

Exposure to sunlight aids in the body's production of vitamin D, guards against rickets, and treats newborn jaundice. In Ethiopia, the magnitude of sunlight exposure practice varies across studies. Thus, this study aimed to estimate the pooled practices and factors associated with sunlight exposure of infants among mothers in Ethiopia.

METHODS

Electronic search was carried out using databases (PubMed, HINARI, Science Direct, electronic databases, and Google Scholar) for relevant articles published from January 1, 2010, to March 27, 2024. The screening process was carried out in accordance with PRISMA guidelines. Articles conducted in English and quantitatively expressed were considered in this review. The quality assessment of included articles was evaluated using the Newcastle-Ottawa Scale. Data analysis was carried out using STATA-14 version software. I2 statistics and Egger's test were used to evaluate heterogeneity and publication bias, respectively. The pooled prevalence with a 95% confidence interval (CI) of the meta-analysis utilizing the random effect model was displayed using forest plots, and adjusted odds ratio (AOR) was utilized to quantify the association.

RESULTS

1171 records, 13 studies were included in the meta-analysis with 5190 study participants that fulfill the inclusion criteria, and all the included studies were cross-sectional in design. The pooled prevalence of sunlight exposure practice among mothers in Ethiopia was 45.38% CI (38.36, 52.4). Good sunlight-related knowledge (AOR; 1.61, 95% CI 1.3, 1.98), maternal formal education (AOR; 1.35, 95% CI 1.08, 1.69), housewife (AOR; 0.7, 95% CI 0.51, 0.95), and husband formal education (AOR; 1.29, 95% CI 1.07, 1.56) were significantly associated with good sunlight exposure practice.

CONCLUSION

The pooled prevalence of good sunlight exposure practice among mothers in Ethiopia was low. Good sunlight-related knowledge, being a housewife, and maternal and husband formal education were the factors that were associated with good sunlight exposure practice. Thus, the government needs to cater further assistance and initiate greater information circulation and follow-up to improve the situation.

Mothers Practices and Factors Affecting Sunlight Exposure of Their Infants in Adami Tulu Jido Kombolcha District, East Shoa Zone, Oromia Region, Ethiopia, 2022: A Community Based Cross-Sectional Study

Background. Vitamin D deficiency (VDD) is a global health concern affecting people of all ages. The Ethiopian guidelines recommend sun exposure for neonates starting from 2 weeks old, with 15 to 20 minutes per day. However, evidence suggests that the implementation of this recommendation is inconsistent. Most studies conducted in Ethiopia regarding infant sunlight exposure have been limited to health facilities and towns. Objective. this study aimed to assess mothers' practice, and factors affecting the sunlight exposure of their infants in Adami Tulu Jido Kombolcha district, East Shoa Zone, Oromia Region, Ethiopia, 2022. Method. A community based cross-sectional study design was conducted among 575 mothers with their infant's from March 11 to 25, 2022. A lottery method sampling technique was employed to select local administrative units and systematic random sampling employed to select study participants. Practices and knowledge were assessed by categorizing mothers based on their responses to practice and knowledge questions, respectively. Mothers who scored above the mean value of 4.5 were classified as having good practice, while those who scored 6.9 or below on the knowledge questions were classified as having poor knowledge. Data were collected through face-to-face interviews using both semi-structured and structured questionnaires. The data were then entered into EPI Data version 3.1 and exported to SPSS version 25 for analysis. The association between variables was analyzed using bivariate and multivariable binary logistic regression and level of significant determined with adjusted odd ratio at 95% CI and P-value less than <.05. Result. All 575 mothers were interviewed and responded 100%. Out of 567 mothers, 55.2% had good practice of infant sunlight exposure. Lack of advice at health facility (AOR = 3.05, 95% CI: 1.08, 8.60), absence of postnatal care follow up (AOR = 2.38, 95% CI: 1.15, 4.94) and poor knowledge about sunlight exposure (AOR = 1.70, 95% CI: 1.15, 2.50) were factors associated with practice of infant sunlight exposure. Conclusions. In this study, more than half of the mothers had good practice of infants' sunlight exposure. This study highlights the importance of improving maternal knowledge and healthcare practices related to infant sunlight exposure. Key factors affecting these practices include lack of advice at health facilities, absence of postnatal care follow-up, and poor maternal knowledge. To address these issues, healthcare providers, local health offices, and mass media should focus on educational programs and strengthening advice during health visits. Future research should use validated tools and mixed-method approaches to better understand the social and cultural factors at play. Establishing national guidelines and studying infant serum vitamin D levels can further enhance community awareness and promote the benefits of sunlight exposure.

An Overview of Different Vitamin D Compounds in the Setting of Adiposity

A large body of research shows an association between higher body weight and low vitamin D status, as assessed using serum 25-hydroxyvitamin D concentrations. Vitamin D can be metabolised in adipose tissue and has been reported to influence gene expression and modulate inflammation and adipose tissue metabolism in vitro. However, the exact metabolism of vitamin D in adipose tissue is currently unknown. White adipose tissue expresses the vitamin D receptor and hydroxylase enzymes, substantially involved in vitamin D metabolism and efficacy. The distribution and concentrations of the generated vitamin D compounds in adipose tissue, however, are largely unknown. Closing this knowledge gap could help to understand whether the different vitamin D compounds have specific health effects in the setting of adiposity. This review summarises the current evidence for a role of vitamin D in adipose tissue and discusses options to accurately measure vitamin D compounds in adipose tissue using liquid chromatography tandem mass spectrometry (LC/MS-MS).

Prevalence of cataract and its contributing factors in Iranian elderly population: the Gilan eye study

PURPOSE

To report the prevalence and the associated factors leading to cataract among the Iranian population living in Gilan Province, Iran.

METHODS

This population-based cross-sectional study was performed from June to November 2014 on 2,975 residents aged ≥ 50 years old living in urban and rural regions of the Gilan Province in Iran. A representative sample of residents in the province was recruited into the study through door-to-door visiting, and baseline data were collected by questionnaire. All participants were referred to the medical center for comprehensive ophthalmic examination, laboratory tests, and blood pressure measurement.

RESULTS

Among the population, 2,588 (86.99%) subjects were eligible to be included in this study, categorized either into the cataract or the non-cataract group. The mean age of participants was 62.59 ± 8.92 years, and 57.5% were female. Higher prevalence of cataract was found in individuals of older ages (odds ratio (OR) = 1.13; 95% confidence interval (CI) = 1.10 to 1.16; P < 0.001) and a history of previous ocular surgery (OR = 5.78; 95% CI = 2.28 to 14.63; P < 0.001). At the same time, a lower prevalence of cataract was seen in patients exposed to sunlight for more than 4 h per day (OR = 0.49; 95% CI = 0.32 to 0.73; P = 0.001).

CONCLUSION

Cataract affects 50.50% of the study population, especially those over 80. The mildest form of cataract, grade zero, is the most common. Surgery for cataract has good outcomes. The risk of cataract is higher for those older or who have had eye surgeries. People not affected by cataract tend to be exposed to more sunlight.

Prevalence of vitamin D deficiency in South America: a systematic review and meta-analysis

CONTEXT

Vitamin D deficiency is considered a global public health issue, even in low-latitude countries where there is abundant sunlight radiation. Nevertheless, the prevalence of vitamin D insufficiency and deficiency in the South American continent has not been well characterized.

OBJECTIVE

The aim of this review was to estimate the prevalence of vitamin D deficiency (25-hydroxy-calciferol < 20 ng/mL) in South American populations.

DATA SOURCES

Seven electronic databases (MEDLINE, Web of Science, Embase, Biblioteca Virtual de Saúde, SciELO, Scopus, and Google Scholar) were searched systematically for observational studies published before July 1, 2021, and reporting vitamin D status of healthy adults in South America.

DATA EXTRACTION

Data were extracted using a standardized form. Risk of bias was assessed by the Joanna Briggs Institute Critical Appraisal Instrument for Studies Reporting Prevalence. All steps were conducted independently by two authors. Data were pooled using a random-effects model. Stratified meta-analysis and meta-regression were conducted (R software).

DATA ANALYSIS

Of 9460 articles identified, 96 studies with a total of 227 758 participants were included. The overall prevalence of vitamin D deficiency was 34.76% (79 studies; 95%CI, 29.68-40.21; I2 = 99%). There were significant differences in prevalence rates related to age, sex, country, latitude, season, and year of publication.

CONCLUSION

The prevalence of vitamin D deficiency is unexpectedly elevated in South American populations. Public health strategies should include efforts to prevent, detect, and treat vitamin D deficiency.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD42020169439.

Association of sun exposure and seasonality with vitamin D levels in Brazilian children and adolescents

OBJECTIVE

This study aimed to verify vitamin D concentration in children and adolescents during the seasons of the year and to compare vitamin D concentration between children engaged in outdoor activities and those engaged in indoor activities.

METHODS

This is a cross-sectional study with a sample of 708 children and adolescents (aged 6-18 years), excluding 109 (16 were over 19 years old; 39 had a disease that required continuous treatment; 20 were on continuous medication; and 34 had no vitamin D data), ending with 599. The plasma concentration of 25-hydroxyvitamin D2 was measured with commercial kits following manufacturer instructions.

RESULTS

Participants who engaged in outdoor activities, as well as those who had data collected during summer and spring, had higher levels of vitamin D. According to the Poisson regression, the proportion of participants with inadequate levels of vitamin D was greater in the participants whose vitamin D was measured during spring (PR 1.15, 95%CI 1.03-1.29) and winter (PR 1.18, 95%CI 1.05-1.32). Also, a greater proportion of inadequate vitamin D was observed for those engaged in indoor activities (PR 1.08, 95%CI 1.01-1.15).

CONCLUSIONS

Participants who measured the vitamin during the summer and autumn had a lower prevalence of hypovitaminosis D. Even in regions with high solar incidence throughout the year, vitamin D levels can vary significantly during the period's seasons.

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.

The effect of antiretroviral therapy initiation on vitamin D levels and four oral diseases among Kenyan children and adolescents living with HIV

OBJECTIVES

The impact of antiretroviral treatment (ART) on the occurrence of oral diseases among children and adolescents living with HIV (CALHIV) is poorly understood. The aim of this study was to determine the effect of ART timing on vitamin D levels and the prevalence of four oral diseases (dry mouth, dental caries, enamel hypoplasia, and non-herpes oral ulcer) among Kenyan CALHIV from two pediatric HIV cohorts.

METHODS

This nested cross-sectional study was conducted at the Kenyatta National Hospital, Nairobi, Kenya. CALHIV, 51 with early-ART initiated at <12 months of age and 27 with late-ART initiated between 18 months-12 years of age, were included. Demographics, HIV diagnosis, baseline CD4 and HIV RNA viral load data were extracted from the primary study databases. Community Oral Health Officers performed oral health examinations following standardized training.

RESULTS

Among 78 CALHIV in the study, median age at the time of the oral examination was 11.4 years old and median ART duration at the time of oral examination was 11 years (IQR: 10.1, 13.4). Mean serum vitamin D level was significantly higher among the early-ART group than the late-ART group (29.5 versus 22.4 ng/mL, p = 0.0002). Children who received early-ART had a 70% reduction in risk of inadequate vitamin D level (<20 ng/mL), compared to those who received late-ART (p = 0.02). Although both groups had similar prevalence of oral diseases overall (early-ART 82.4%; late-ART 85.2%; p = 0.2), there was a trend for higher prevalence of dry mouth (p = 0.1) and dental caries (p = 0.1) in the early versus late ART groups. The prevalence of the four oral diseases was not associated with vitamin D levels (p = 0.583).

CONCLUSIONS

After >10 years of ART, CALHIV with early-ART initiation had higher serum vitamin D levels compared to the late-ART group. The four oral diseases were not significantly associated with timing of ART initiation or serum vitamin D concentrations in this cohort. There was a trend for higher prevalence of dry mouth and dental caries in the early-ART group, probably as side-effects of ART.

Vitamin D levels on sports injuries in outdoor and indoor athletes: a cross-sectional study

OBJECTIVE

Having vitamin D levels within normal limits is important for bone and muscle health and its deficiency may increase the risk of injury. The aim of this cross-sectional study was to investigate whether vitamin D levels are different in indoor and outdoor athletes and its levels increase the risk of injury.

MATERIAL AND METHODS

Serum vitamin D levels were measured in Caucasian adolescent athletes, who admitted to the sports medicine polyclinic due to a routine health check or injury. The study was carried out at 38°26' north latitude in İzmir between June and September 2019. After the physical examination of the injured athletes, the diagnoses were made accompanied by the findings obtained by imaging methods in cases of necessity.

RESULTS

A total of 256 athletes, including swimmers (n = 87), basketball players (n = 104), and football (n = 65) players aged 13.2 (± 2.2) years, were investigated. The average serum vitamin D (25(OH)D) level in athletes was 29.2 (±10.0) ng/mL (6.0-66.0 ng/mL). Forty-six of all athletes (18%) had vitamin D deficiency, with a mean value of 15.7 (±4.0) ng/mL, and 93 of them (36.3%) had vitamin D deficiency with a mean value of 25.2 (±2.4) ng/mL. While vitamin D levels were significantly higher in football players (32 ng/mL) than in other athletes (p < 0.05), it was similar in basketball players (27 ng/mL) and swimmers (26 ng/mL) (p > 0.05). Vitamin D levels (26 ng/mL) of the injured athletes were significantly lower than those of the non-injured athletes (30 ng/mL) (p = 0.001). Bone injuries were significantly related to Vitamin D levels (p < 0.001) but not with muscle injuries (p > 0.05).

CONCLUSION

Frequency of vitamin D deficiency and insufficiency is higher in indoor athletes andis especially associated with risk of bone injuries . In order to examine the effect of vitamin D level on bone mineral density, comprehensive prospective studies are required.

An Update on Vitamin D Deficiency Status in Malaysia

Vitamin D is essential for maintaining serum calcium levels, ensuring sufficient bone mineralization, immunomodulatory properties, and a protective effect on the cardiovascular system, renal disease, cancer, as well as in pregnancy. Vitamin D deficiency is prevalent worldwide, and it is not related to a country's development index. However, the data on vitamin D deficiencies are primarily taken from out-of-date, small-scale studies on target age groups or specific diseases, rather than from large-scale, population-based surveys. In Malaysia, for the past 16 years, studies were conducted involving adult men and women, pregnant women, postmenopausal women, adolescent, and children especially with specific diseases such as spina bifida, epilepsy, chronic liver disease, and atopic dermatitis. Only a few large surveys were conducted involving children and adolescents. Across the specific target population studied, vitamin D deficiency and insufficiency were seen particularly among females, Indians, and those of Malay ethnicity. This is related to widely known causes of vitamin D deficiency such as skin type (melanin) and sun avoidant lifestyles that include covering clothes, largely practiced by Malay Muslims in Malaysia. Other related causes or the high-risk groups are breastfed infants, the elderly, the obese, those on medications, and those characterized by fat malabsorption and geophysical factors. Vitamin D deficiency can be managed with pharmacological or non-pharmacological approaches, depending on the severity. The objective is to raise serum vitamin D to a normal level, hence, relieving the symptoms and reducing the adverse health outcomes. Despite no clear guidelines in treating vitamin D deficiency in Malaysia, this condition can be prevented with taking adequate vitamin D in food resources, sun exposure, or supplementation. Special attention should be given to high-risk groups including infants, obese patients, and the elderly.

Vitamin D decreases pancreatic iron overload in type 2 diabetes through the NF-κB-DMT1 pathway

Emerging evidence has deemed vitamin D as a potential candidate for the intervention of type 2 diabetes (T2D). Herein, we explored the underlying mechanisms of T2D prevention by vitamin D, concentrating on pancreatic iron deposition reported recently. Zucker diabetic fatty (ZDF) rats were treated by vitamin D, with age-matched Zucker lean rats as control. As expected, vitamin D treatment for ZDF rats normalized islet morphology and β-cell function. Moreover, vitamin D alleviated iron accumulation and apoptosis in pancreatic cells of ZDF rats, accompanied by lowered divalent metal transporter 1 (DMT1) expression. Consistently, similar results were observed in high glucose-stimulated INS-1 cells treated with or without vitamin D. Nuclear factor-κB (NF-κB), a transcription factor involving DMT1 regulation, was activated in pancreases of ZDF rats and INS-1 cells exposed to high glucose, but inactivated by vitamin D or BAY 11-7082, a NF-κB inhibitor. Futhermore, IL-1β functioning as NF-κB activator abolished the suppression of NF-κB activation, DMT1 induction and the attenuation of apoptosis as a consequence of vitamin D incubation. Our study showed that iron overload in pancreas may contribute to T2D pathogenesis and uncovered a potentially protective role for vitamin D on iron deposition of diabetic pancreas through NF-κB- DMT1 signaling.

Vitamin D and Stress Fractures in Sport: Preventive and Therapeutic Measures-A Narrative Review

There are numerous risk factors for stress fractures that have been identified in literature. Among different risk factors, a prolonged lack of vitamin D (25(OH)D) can lead to stress fractures in athletes since 25(OH)D insufficiency is associated with an increased incidence of a fracture. A 25(OH)D value of <75.8 nmol/L is a risk factor for a stress fracture. 25(OH)D deficiency is, however, only one of several potential risk factors. Well-documented risk factors for a stress fracture include female sex, white ethnicity, older age, taller stature, lower aerobic fitness, prior physical inactivity, greater amounts of current physical training, thinner bones, 25(OH)D deficiency, iron deficiency, menstrual disturbances, and inadequate intake of 25(OH)D and/or calcium. Stress fractures are not uncommon in athletes and affect around 20% of all competitors. Most athletes with a stress fracture are under 25 years of age. Stress fractures can affect every sporty person, from weekend athletes to top athletes. Stress fractures are common in certain sports disciplines such as basketball, baseball, athletics, rowing, soccer, aerobics, and classical ballet. The lower extremity is increasingly affected for stress fractures with the locations of the tibia, metatarsalia and pelvis. Regarding prevention and therapy, 25(OH)D seems to play an important role. Athletes should have an evaluation of 25(OH)D -dependent calcium homeostasis based on laboratory tests of 25-OH-D3, calcium, creatinine, and parathyroid hormone. In case of a deficiency of 25(OH)D, normal blood levels of ≥30 ng/mL may be restored by optimizing the athlete's lifestyle and, if appropriate, an oral substitution of 25(OH)D. Very recent studies suggested that the prevalence of stress fractures decreased when athletes are supplemented daily with 800 IU 25(OH)D and 2000 mg calcium. Recommendations of daily 25(OH)D intake may go up to 2000 IU of 25(OH)D per day.

[Vitamin D Deficiency in Sports]

Vitamin D Deficiency in Sports Abstract. A deficiency in vitamin D is very common in the general population as well as in athletes. The aim of this overview is to assess the level of knowledge about the importance of vitamin D for athletes. A deficiency in vitamin D is present in up to 90 % of athletes. Risk groups are young athletes, female athletes, athletes with a limitation such as paraplegia, vegetarians, athletes with a resorption disorder such as celiac disease, athletes training and competing indoors (e.g. ice hockey, basketball, boxing, rhythmic gymnastics), and older athletes. Dark skin pigmentation, the use of sunscreen, the time of day of the training (early morning, late evening) and the geographical location influence the risk for a deficiency in vitamin D. Exposure to the sun and a balanced diet are often not enough to prevent a vitamin D deficiency.

Vitamin D Intake in a Population-Based Sample of Young Polish Women, Its Major Sources and the Possibility of Meeting the Recommendations

The recommendations of vitamin D intake are commonly not met, which results from the fact that fish, being its major sources, are commonly rarely consumed. Consequently, a reliable estimation of its habitual intake is also difficult, as its daily intake is highly variable. The aim of the study was to analyze vitamin D intake from food, its major sources and the possibility to meet its recommendations in a population-based sample of young Polish women. The study was conducted in a sample of Polish women aged 15–30 years, recruited in cooperation with local students’ and youth organizations from all regions of Poland (convenience sampling with the snowball effect), while the stratified sampling procedure was applied with a random quota sampling for voivodeships (an administrative subdivision), to obtain an adequate distribution regarding the general population of young Polish women (n = 1,032). The vitamin D intake was assessed while using the validated Vitamin D Estimation Only—Food Frequency Questionnaire (VIDEO-FFQ) and was compared with the recommended 10 µg. The median vitamin D intake in the study group was 3.09 µg (0.00–24.52 µg) and in 95% of participants was lower than recommended, while the highest vitamin D intake was observed for the following sources: eggs (0.50 µg), meat and meat products (0.49 µg), herring, sardine and tuna products (0.41 µg) and dairy products (0.40 µg). The correlation between total vitamin D intake and its intake from its sources was strongest for eggs (p < 0.0001; R = 0.5989) and for herring, sardine and tuna products (p < 0.0001; R = 0.5314), while the correlation between total vitamin D intake and the number of servings was strongest for herring, sardine and tuna products (p < 0.0001; R = 0.5314). At the same time, while compared with other fish species, consuming herring was the strongest predictor of meeting the recommended vitamin D level of 10 µg (p = 0.0292; odds ratio (OR) = 1.94; 95% confidence interval (CI) 1.07–3.52), but also of 5 µg (p < 0.0001; OR = 2.54; 95% CI 1.85–3.47). Therefore, taking into account the relatively low prices of herring, its high vitamin D content, as well as its influence on total vitamin D intake, it could be beneficial to recommend young women to increase herring intake in order to increase dietary vitamin D intake and to meet its recommendations.

Need of the Hour

Belonging to Millennial generation, Generation Z and Generation Alpha we have lot of changes in livelihood and lifestyle. From an orthopaedic surgeons perspective, we notice a change in diseases and disorders specific to this millennial generation. Lot of changes in lifestyle of people in past 20 years have caused newer challenges in the way doctors have been treating their patients. I hereby present a sneak peek into some of the generation specific diseases and disorders due to rampant explosion of technology in past twenty-five years. From usage of mobile phones to computers and the way we commute every day. The way we sit, the way we sleep and the way some of the young generation earns livelihood has many disorders related to posture, stress, overuse and work environment.

Food-based strategies for prevention of vitamin D deficiency as informed by vitamin D dietary guidelines, and consideration of minimal-risk UVB radiation exposure in future guidelines

There is widespread acknowledgement of the presence of vitamin D deficiency in the community and the pressing need to address this. From a public health perspective, emphasis has been placed on addressing vitamin D deficiency through dietary means. However, naturally rich food sources of vitamin D are few and infrequently consumed, and nutrition survey data from various countries have indicated that habitual vitamin D intakes in the community are much lower than the current vitamin D dietary guidelines. This review will briefly overview the extent of vitamin D deficiency within the community, its causes, and how our food chain, once its embraces the evidence-based practise of food fortification and potentially biofortification, can cater for meeting the dietary vitamin D needs of the community. Finally, international authorities, briefed with establishing vitamin D dietary guidelines over the past decade, have struggled with uncertainties and gaps in our understanding of the relative contribution of sunshine and diet to vitamin D status and vitamin D requirements for health maintenance. The review will also consider how emerging evidence of a possible minimal-risk UVB radiation exposure relative to skin cancer that also enables vitamin D production could greatly inform future vitamin D dietary guidelines.

Vitamin D Deficiency: Defining, Prevalence, Causes, and Strategies of Addressing

There are variable definitions of vitamin D deficiency, based on different thresholds of serum 25-hydroxyvitamin D (25(OH)D); this has a major bearing on the prevalence estimates of vitamin D deficiency and consequently on the magnitude of the public health issue of low vitamin D status. Despite this, there is widespread acknowledgement of the presence of vitamin D deficiency, even using the most conservative serum 25(OH)D threshold of < 25/30 nmol/L, in both low- and high-income country setting and the pressing need to address this deficiency. While ultraviolet B-rich sunlight stimulates synthesis of vitamin D in skin, there are environmental factors and personal characteristics which prevent or impede such dermal synthesis. There are several complexities and concerns in advocating sun exposure as a public health approach for increasing vitamin D status. This places increased emphasis on addressing vitamin D deficiency through dietary means. However, naturally rich sources of vitamin D are few and infrequently consumed, and nutrition surveillance data from various countries have indicated that habitual vitamin D intakes in the population are much lower than the recommendations. There are a number of strategies that can be considered for the control of micronutrient malnutrition, these include (i) increasing the diversity of foods consumed, (ii) food fortification, and (iii) supplementation. The present narrative review will consider these strategies for addressing low dietary vitamin D intake and consequently lowering the risk of vitamin D deficiency.

High prevalence of vitamin D insufficiency in professional handball athletes

OBJECTIVES

Vitamin D affects multiple body functions through the regulation of gene expression. In sports medicine, its influence on musculoskeletal health and performance is of particular interest. Vitamin D insufficiency might decrease athletic performance and increase the risk of musculoskeletal injuries. Several studies have demonstrated vitamin D deficiency in professional athletes; however, the prevalence of vitamin D insufficiency in professional handball players is yet unknown.

METHODS

The study was planned as a prospective, non-interventional study. We examined 70 male elite handball athletes (first league) in a pre-competition medical assessment in July. Age, height, weight, body mass index, 25-OH vitamin D, calcium, and parathyroid hormone were evaluated, and a sun exposure score was calculated. Players were then divided into two groups of vitamin D levels: insufficient (<30 ng/mL) and sufficient (≥30 ng/mL).

RESULTS

The mean 25-OH vitamin D level of the 70 players was 33.5 ± 10.9 ng/mL (median 32.2, IQR 26.5-38.9 ng/mL). Thirty-nine (55.7%) had sufficient and 31 (44.3%) insufficient levels. Athletes with sufficient vitamin D levels had significantly lower parathyroid hormone levels than athletes with insufficiency (24.9 ± 12.1 vs. 33.5 ± 15.1 ng/mL, p = 0.02). All other parameters evaluated demonstrated no significant difference between the two groups.

CONCLUSION

Vitamin D insufficiency is a common finding in professional handball athletes even in summer, which might negatively affect physical performance. Furthermore, it might lead to an increased risk of musculoskeletal injuries and infections. This should be evaluated in further studies.

Development of Vitamin D Toxicity from Overcorrection of Vitamin D Deficiency: A Review of Case Reports

Over the past two decades, vitamin D level measurements have become some of the most frequently ordered tests in the laboratory. This increase is due to a growing awareness of widespread vitamin D deficiency and scientific data suggesting the beneficial effects of vitamin D in various diseases. A literature search was carried out in PubMed for cases reporting vitamin D intoxication and overdose. Thirteen articles were included in this review. Intoxication was severe in the reported cases. Patients presented with serum vitamin D concentrations ranging between 150 and 1220 ng/mL and serum calcium concentrations between 11.1 and 23.1 mg/dL. Most of the reported patients showed symptoms of vitamin D toxicity such as vomiting, dehydration, pain, and loss of appetite. The underlying causes included manufacturing errors, overdosing by patients or prescribers, and combinations of these factors. Our literature search highlights the fact that even though vitamin D intoxication is rare, it does occur and therefore patients and prescribers should be more cognizant of the potential dangers of vitamin D overdose.

10 years of 25-hydroxyvitamin-D testing by LC-MS/MS-trends in vitamin-D deficiency and sufficiency

In early 2000's vitamin-D deficiency was shown to be prevalent in several countries including the United States (US). Studies exploring the role of vitamin-D metabolism in diverse disease pathways generated an increased demand for vitamin-D supplementation and an immense public interest in measurement of vitamin-D metabolite levels. In this report, we review the role of vitamin-D metabolism in disease processes, clinical utility of measuring vitamin-D metabolites including 25-hydroxyvitamin-D (25(OH)D), 1,25-dihydroxyvitamin-D and 24,25-dihydroxyvitamin-D and discuss vitamin-D assay methodologies including immunoassays and liquid chromatography mass spectrometry (LC-MS/MS) assays. We also provide examples of vitamin-D toxicity and insight into the trends in serum 25(OH)D levels in the US population based on 10 years of data from on serum 25(OH)D values from ~5,000,000 patients who were tested at the Mayo Medical Laboratories between February 2007-February 2017.

Higher serum 25-hydroxyvitamin D concentrations are associated with active pulmonary tuberculosis in hospitalised HIV infected patients in a low income tropical setting: a cross sectional study

Background

The inherent risk of developing tuberculosis (TB) in HIV- infected individuals is further enhanced by hypovitaminosis D. Interventions that offset HIV-associated immune deterioration potentially arrest disease progression and incidence of opportunistic infections including TB. Despite conflicting reports on association between vitamin D deficiency (VDD) and risk of TB, vitamin D (VD) supplementation remains a promising intervention.

Methods

We conducted a comparative cross-sectional study on 145 HIV⁺/pulmonary TB⁺ (PTB) and 139 HIV⁺/PTB⁻ hospitalised patients to investigate association of vitamin D status and risk of PTB. Stratified random sampling was used to select archived serum specimens from participants enrolled in a randomised controlled trial (RCT) conducted to investigate the impact of using a point-of-care urine lipoarabinomannan strip test for TB diagnosis. PTB status was confirmed using sputum smear microscopy, culture or GeneXpert MTB/RIF. Serum 25-hydroxyvitamin D [25(OH) D] concentrations were assayed by competitive chemiluminescent immunoassay prior to commencement of anti-TB treatment. Effect of VD status on duration of hospital stay and patient outcomes on follow up at 8 weeks were also investigated. Median serum 25(OH) D concentrations were compared using Mann-Whitney test and covariates of serum VD status were assessed using logistic regression analysis.

Results

Overall VDD prevalence in the cohort was 40.9% (95% CI: 35.1–46.8). Median serum 25(OH)D concentrations were significantly higher in HIV⁺/PTB⁺ group (25.3 ng/ml, IQR:18.0–33.7) compared to the HIV⁺/PTB⁻ group (20.4 ng/ml, IQR:14.6–26.9), p = 0.0003. Patients with serum 25(OH) D concentration ≥ 30 ng/ml were 1.9 times more likely to be PTB⁺ compared to those with serum 25(OH) D concentrations < 30 ng/ml (odds ratio (OR) 1.91; 95% CI 1.1–3.2). PTB-related death was associated with higher odds of having 25(OH) D levels≥30 ng/ml. Age, gender, CD4⁺ count, combination antiretroviral therapy (cART) status, efavirenz based cART regimen and length of hospital stay were not associated with vitamin D status.

Conclusions

The finding of an association between higher serum 25(OH) D concentrations and active PTB and TB-related mortality among hospitalised HIV-infected patients in the present study is at variance with the commonly reported association of hypovitaminosis and susceptibility to TB. Our findings though, are in concordance with a small pool of reports from other settings.

Healthy changes in some cardiometabolic risk factors accompany the higher summertime serum 25-hydroxyvitamin D concentrations in Iranian children: National Food and Nutrition Surveillance

OBJECTIVE

To investigate seasonal variations of vitamin D status at different latitudes and if these changes are accompanied by corresponding variations in certain health parameters in children living in a broad latitudinal range in Iran.

DESIGN

Longitudinal study.

SUBJECTS

In total, 530 apparently healthy children aged 5-18 years were randomly selected from six regions of Iran with a latitudinal gradient from 29°N to 37·5°N. All anthropometric and biochemical assessments were performed twice during a year (summer, winter). High BMI (Z-score >1), low HDL cholesterol (150 mg/dl) were considered cardiometabolic risk factors.

RESULTS

Serum 25-hydroxyvitamin D (25(OH)D) showed between-season variation, with significantly higher concentrations (mean (sd)) in summer v. winter (43 (29) v. 27 (18) nmol/l; P33°N v. <33°N: 4·5; 0·09, 9·0; P=0·04) were predictors of change of serum 25(OH)D between two seasons.

CONCLUSIONS

Summertime improvement of vitamin D status was accompanied by certain improved cardiometabolic risk factors, notably serum TAG, total cholesterol and BMI, in children.

25-Hydroxyvitamin D as a Biomarker of Vitamin D Status and Its Modeling to Inform Strategies for Prevention of Vitamin D Deficiency within the Population

There is substantial evidence that the prevalence of vitamin D deficiency is unacceptably high in the population, and this requires action from a public health perspective. Circulating 25-hydroxyvitamin D [25(OH)D] is a robust and reliable marker of vitamin D status and has been used by numerous agencies in the establishment of vitamin D dietary requirements and for population surveillance of vitamin D deficiency or inadequacy. In a wider context, modeling of serum 25(OH)D data and its contributory sources, namely dietary vitamin D supply and UVB availability, can inform our understanding of population vitamin D status. The aim of this review is to provide the current status of knowledge in relation to modeling of such vitamin D-relevant data. We begin by highlighting the importance of the measurement of 25(OH)D and its standardization, both of which have led to new key data on the prevalence of vitamin D deficiency and inadequacy in North America and Europe. We then overview how state-of-the-art modeling can be used to inform our understanding of the potential effect of ergocalciferol and 25(OH)D on vitamin D intake estimates and how meteorological data on UVB availability, when coupled with other key data, can help predict population serum 25(OH)D concentration, even accounting for seasonal fluctuations, and lastly, how these in silico approaches can help inform policymakers on strategic options on addressing low vitamin D status through food-based approaches and supplementation. The potential of exemplar food-based solutions will be highlighted, as will the possibility of synergies between vitamin D and other dairy food-based micronutrients, in relation to vitamin D status and bone health. Lastly, we will briefly consider the interactions between season and vitamin D supplements on vitamin D status and health.

Vitamin D status and cardiometabolic risk factors across latitudinal gradient in Iranian adults: National food and nutrition surveillance

BACKGROUND

This study aimed to evaluate the vitamin D status in an adult population across latitudinal gradient and to investigate its possible associations with certain cardiometabolic risk factors.

METHODS

A total of 1406 healthy subjects aged 19-60 years were randomly selected from six regions of Iran across latitudinal gradient from 29° N to 37.5° N. Anthropometric and biochemical assessments were performed. The combination of high body mass index (>25 kg/m²), low high-density lipoprotein cholesterol (< 40 mg/dl in males and < 50 mg/dl in females) and high triglycerides (> 150 mg/dl) was defined as cardiometabolic risk factors.

RESULTS

The mean concentration of serum 25-hydroxycalciferol (25(OH)D) was 26.8±17.7 nmol/l. There were no significant differences in the mean serum 25(OH)D levels among different latitudes. Undesirable vitamin D status (deficiency and insufficiency) was found in 90.7% of the subjects. After adjustment for age and gender, the association between weight status and serum 25(OH)D was significant ( p< 0.04, odds ratio:1.49; confidence interval: 1.01-2.19). The prevalence of cardiometabolic risk factors among the subjects with serum 25(OH)D less than 27.5 nmol/l was significantly higher than those with serum calcidiol concentrations above 27.5 nmol/l (13.3% vs. 10.0%, p = 0.033).

CONCLUSION

Undesirable vitamin D status is highly prevalent among Iranian adults of both sexes irrespective of latitude and even in sunny regions. The occurrence of cardiometabolic risk factors was significantly higher in those subjects with circulating calcidiol concentrations below 27.5 nmol/l.

Prevalence of Vitamin D Insufficiency in Professional Hockey Players

Background:

Vitamin D is a fat-soluble hormone that plays a role in bone health, muscle function, and athletic performance. Studies have shown that low levels of vitamin D can lead to slower muscle recovery and function, increased rates of stress fractures, and even poorer athletic performance. Insufficient vitamin D levels have been demonstrated in professional basketball and football players, however, there have been no studies to date reviewing vitamin D insufficiency in professional hockey players.

Purpose/Hypothesis:

The purpose of this study was to perform a cross-sectional review to determine the prevalence of vitamin D deficiency and insufficiency in professional hockey players. The hypothesis was that there would be a high percentage of players with vitamin D insufficiency.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

The preseason serum 25-hydroxy (OH) vitamin D laboratory test results of 105 professional hockey players were retrospectively reviewed. All players on 3 National Hockey League (NHL) teams were included. Player parameters evaluated included age, height, weight, body mass index, and 25(OH) vitamin D level. Players were divided into 4 groups based on serum vitamin D levels: deficient (<20 ng/mL), insufficient (20-31.9 ng/mL), sufficient (≥32 ng/mL), and ideal (≥40 ng/mL). Descriptive statistics were performed, in addition to 2-group and 3-group comparisons.

Results:

The average 25(OH) vitamin D level of 105 players was 45.8 ± 13.7 ng/mL (range, 24-108 ng/mL). No players in the study were considered deficient. A total of 14 players (13.3%) were considered insufficient, while 91 players (86.7%) were considered sufficient. However, only 68 players (64.8%) were considered ideal. When comparing groups, athletes with sufficient vitamin D levels were older than athletes with insufficient vitamin D levels (25.9 vs 23.1 years; P = .018). All other player parameters demonstrated no significant difference between groups.

Conclusion:

Despite playing a winter sport and spending a great deal of time training indoors, professional hockey players have low levels of vitamin D insufficiency.

Malnutrition in Bariatric Surgery Candidates: Multiple Micronutrient Deficiencies Prior to Surgery

BACKGROUND

Over 78 million American adults have obesity. Bariatric surgery is the leading means of durable weight loss. Nutritional deficiencies are commonly treated post-operatively but are often undiagnosed pre-operatively. Malnutrition is correlated with adverse surgical outcomes.

OBJECTIVES

The aim of this study is to assess pre-operative nutritional status in our bariatric surgery candidates in a cross-sectional study.

METHODS

We recruited 58 bariatric candidates approved to undergo the Roux-en Y gastric bypass. Nutritional status was determined for vitamins A, B12, D, E-α, and E-β/γ as well as thiamine, folate, and iron. We used clinical as well as frank deficiency cut-offs based on the Institute of Medicine and the World Health Organization guidelines.

RESULTS

This cohort was largely female (77.6%) and white (63.8%). Median age was 42.2 years. Median body mass index (BMI) was 46.3 kg/m(2). Multiple comorbidities (MCM) were present in 41.4%, 54.0% hypertension, 42.0% diabetic, 34.0% sleep apnea. Men had more comorbidities, 69.2 % with MCM. Folate and iron saturation varied significantly by sex. Vitamins A, D, E-α, and thiamine significantly varied by race. Vitamin D negatively correlated with BMI (p = 0.003) and age (p = 0.030). Vitamin A negatively correlated with age (p = 0.001) and number of comorbidities (p = 0.003). These pre-operative bariatric candidates had significant malnutrition, particularly in vitamin D (92.9%) and iron (36.2 to 56.9 %). Multiple micronutrient deficiency (MMND) was more common in blacks (50.0 versus 39.7% overall). Number of comorbidities did not correlate with MMND.

CONCLUSIONS

Malnutrition in one or multiple micronutrients is pervasive in this pre-operative bariatric cohort. The effect of pre-operative supplementation, especially vitamin D and iron, should be explored.

Vegetarian diet and reduced uterine fibroids risk: A case-control study in Nanjing, China

AIM

The aim of this study was to investigate whether a vegetarian diet correlates with a potential reduced risk of uterine fibroids.

MATERIAL AND METHODS

We used data from a case-control study conducted in Southeast University Zhongda Hospital between February 2010 and December 2014. Cases included 600 Chinese Han women with uterine fibroids (case group) whose clinical diagnosis dated back no more than 1 year. Controls were 600 patients without uterine fibroids as well as healthy volunteers (control group). All of the information gathered through the questionnaire survey was analyzed for the risk factors of the uterine fibroids pathogenesis.

RESULTS

The multifactor analysis showed that women with uterine fibroids reported a less frequent consumption of broccoli (odds ratio [OR]: 0.552; 95% confidence interval [CI]: 0.316-0.964), cabbage (OR: 0.446; 95%CI: 0.211-0.943), Chinese cabbage (OR: 0.311; 95%CI: 0.102-0.946), tomato (OR: 0.453; 95%CI: 0.241-0.853), and apple (OR: 0.416; 95%CI: 0.213-0.814) (P < 0.05).

CONCLUSION

The original evidence from this epidemiological investigation shows that a high consumption of broccoli, cabbage, Chinese cabbage, tomato and apple seems to be a protective factor for uterine fibroids. We suggest that greater intake of fresh fruits and cruciferous vegetables may be able to reduce the incidence of uterine fibroids.

Vitamin D Deficiency in Unselected Patients from Swiss Primary Care: A Cross-Sectional Study in Two Seasons

Background

As published data on 25-hydroxy-cholecalciferol (25(OH)D) deficiency in primary care settings is scarce, we assessed the prevalence of hypovitaminosis D, potential associations with clinical symptoms, body mass index, age, Vitamin D intake, and skin type in unselected patients from primary care, and the extent of seasonal variations of serum 25(OH)D concentrations.

Methodology/Principal Findings

25(OH)D was measured at the end of summer and/or winter in 1682 consecutive patients from primary care using an enzyme-linked immunosorbant assay. Clinical symptoms were assessed by self-report (visual analogue scale 0 to 10), and vitamin D deficiency was defined as 25(OH)D concentrations < 50 nmol/l. 25(OH)D deficiency was present in 995 (59.2%) patients. 25(OH)D deficient patients reported more intense muscle weakness (visual analogue scale 2.7, 95% confidence interval 2.5 to 2.9) and had a higher body mass index (25.9kg/m², 25.5 to 26.2) than non-deficient patients (2.5, 2.3 to 2.7; and 24.2, 23.9 to 24.5, respectively). 25(OH)D concentrations also weakly correlated with muscle weakness (Spearman’s rho -0.059, 95% confidence interval -0.107 to -0.011) and body mass index (-0.156, -0.202 to -0.108). Self-reported musculoskeletal pain, fatigue, and age were not associated with deficiency, nor with concentrations. Mean 25(OH)D concentrations in patients with vitamin D containing medication were higher (60.6 ± 22.2 nmol/l) than in patients without medication (44.8 ± 19.2 nmol/l, p < 0.0001) but still below the targeted level of 75 nmol/l. Summer and winter 25(OH)D concentrations differed (53.4 ± 19.9 vs. 41.6 ± 19.3nmol/l, p < 0.0001), which was confirmed in a subgroup of 93 patients who were tested in both seasons (p = 0.01).

Conclusion/Significance

Nearly 60% of unselected patients from primary care met the criteria for 25(OH)D deficiency. Self-reported muscle weakness and high body mass index were associated with lower 25(OH)D levels. As expected 25(OH)D concentrations were lower in winter compared to summer.

"Test me and treat me"--attitudes to vitamin D deficiency and supplementation: a qualitative study

OBJECTIVE

Lay interest in vitamin D and the potential benefits of supplementation is considerable, but little information exists concerning lay knowledge, beliefs and attitudes towards vitamin D to inform public health initiatives and professional guidance.

DESIGN

Qualitative focus group study.

PARTICIPANTS

58 adults capturing diversity in disease status, gender, age and ethnicity.

SETTING

A large general practice in east London.

RESULTS

Many respondents lacked knowledge about vitamin D, including dietary sources and government recommendations. Most were positive about sun exposure, but confused by ambiguous health messages about risks and benefits of sunshine. Medicalised views of vitamin D were prominent, notably from those in favour of supplementation, who talked of "doses", "side effects" and "regular testing." Fortification of food with vitamin D was controversial, with opposing utilitarian (better overall for the majority) and libertarian (freedom to choose) views.

CONCLUSIONS

Knowledge about vitamin D was limited. Clearer messages are needed about risks and benefits of sun exposure. Testing and supplementation by health professionals, while potentially useful in some high-risk groups, have contributed to a medicalised view of vitamin D. Health policy should address the public's need for clear information on sources and effects of vitamin D, including risks and benefits of sun exposure, and take account of divergent views on fortification. Professional guidance is needed on testing and supplementation to counter inappropriate medicalisation.

Investigation on vitamin D knowledge, attitude and practice of university students in Nanjing, China

OBJECTIVE

To investigate university students' knowledge, attitudes and practice (KAP) regarding vitamin D.

DESIGN

The students were requested to answer a questionnaire related to vitamin D and sun exposure. The consumption frequency of foods rich in vitamin D was assessed. Additionally, the intake of vitamin D-containing supplements was recorded.

SETTING

A medical university in Nanjing, China.

SUBJECTS

Five hundred and fifteen medical students were included.

RESULTS

The highest rate of correct responses for the quiz was 68·0 %, while the lowest was 9·6 %. Most students lacked sun exposure because they did not want to get tanned; 82·7 % of students used some sun protection and sunscreen use was more popular in the female group. The consumption frequency of foods rich in vitamin D was low and 5·6 % of the students used vitamin D supplements. The students' knowledge on vitamin D was derived mainly from the media and health professionals. Most of the students were interested to know more about vitamin D.

CONCLUSIONS

The present study suggested that medical students had little knowledge and unfavourable behaviours. They should get more health education through the media and health professionals. It is advisable to increase their consumption of foods rich in vitamin D.

Vitamin D and obesity: current perspectives and future directions

In recent years, new functional roles of vitamin D beyond its traditional role in calcium homoeostasis and bone metabolism have emerged linking the fat-soluble vitamin to various non-communicable diseases. Vitamin D deficiency (25-hydroxyvitamin D (25(OH)D) < 25-30 nmol/l) and sub-optimal status (25(OH)D < 50-100 nmol/l) are increasingly associated with unfavourable metabolic phenotypes, including insulin resistance, type 2 diabetes and CVD; conditions also commonly linked with overweight and obesity. Early studies reported poor vitamin D status in the morbidly obese. More recently, it has been observed that a graded relationship between vitamin D status and BMI, or specifically adiposity, exists in the general population. A number of hypotheses have been proposed to explain the potential mechanisms whereby alterations in the vitamin D endocrine system occur in the obese state. Plausible explanations include sequestration in adipose tissue, volumetric dilution or negative feedback mechanisms from increased circulating 1,25-dihydroxyvitamin D3. Others hypothesise that heavier individuals may partake in less outdoor activity, may also cover-up and wear more clothing than leaner individuals, thus decreasing sun exposure and limiting endogenous production of cholecalciferol in the skin. Moreover, in some but not all studies, BMI and adiposity have been negatively associated with the change in vitamin D status following vitamin D supplementation. It therefore remains unclear if body size and/or adiposity should be taken into account when determining the dietary requirements for vitamin D. This review will evaluate the current evidence linking vitamin D status and supplementation to overweight and obesity, and discuss the implications for setting dietary requirements.

Multiple vitamin deficiencies in a patient with a history of chronic alcohol excess and self-neglect in the UK

We report a case of inadequate diet (caused by extreme self-neglect and alcohol excess) which led to chronic severe deficiencies of vitamins A, D and E. At presentation the patient had widespread follicular hyperkeratosis of the skin, keratomalacia of both eyes and a severe cognitive impairment. He responded well to treatment including high dose parenteral vitamins, but lasting impairments in his vision and cognition have caused permanent disability.

Prevalence of hypovitaminosis D and predictors of vitamin D status in Italian healthy adolescents

Background

Vitamin D plays an important role in health promotion during adolescence. Vitamin D deficiency and insufficiency are common in adolescents worldwide. Few data on vitamin D status and risk factors for hypovitaminosis D in Italian adolescents are currently available.

Methods

25-hydroxyvitamin D (25-OH-D) and parathyroid hormone (PTH) levels were evaluated in 427 Italian healthy adolescents (10.0-21.0 years). We used the following cut-off of 25-OH-D to define vitamin D status: deficiency < 50 nmol/L; insufficiency 50-75 nmol/L; sufficiency ≥ 75 nmol/L. Hypovitaminosis D was defined as 25-OH-D levels < 75.0 nmol/L and severe vitamin D deficiency as 25-OH-D levels < 25.0 nmol/L. We evaluated gender, residence, season of blood withdrawal, ethnicity, weight status, sun exposure, use of sunscreens, outdoor physical activity, and history of fractures as predictors of vitamin D status.

Results

Enrolled adolescents had a median serum 25-OH-D level of 50.0 nmol/L, range 8.1-174.7, with 82.2% having hypovitaminosis D. Vitamin D deficiency and insufficiency were detected in 49.9% and 32.3% of adolescents, respectively. Among those with deficiency, 38 subjects were severely deficient (38/427, 8.9% of the entire sample). Non-white adolescents had a higher prevalence of severe vitamin D deficiency than white subjects (6/17-35.3% vs 32/410-7.8% respectively, p = 0.002). Logistic regression showed increased risk of hypovitaminosis D as follows: blood withdrawal taken in winter-spring (Odds ratio (OR) 5.64) compared to summer-fall period; overweight-obese adolescents (OR 3.89) compared to subjects with normal body mass index (BMI); low sun exposure (OR 5.94) compared to moderate-good exposure and regular use of sunscreens (OR 5.89) compared to non regular use. Adolescents who performed < 3 hours/week of outdoor exercise had higher prevalence of hypovitaminosis D. Gender, residence, and history of fractures were not associated with vitamin D status. Serum 25-OH-D levels were inversely related to PTH (r = -0.387, p < 0.0001) and BMI-SDS (r = -0.141, p = 0.007). 44/427 (10.3%) adolescents showed secondary hyperparathyroidism.

Conclusions

Italian adolescents have high prevalence of vitamin D deficiency and insufficiency. Pediatricians should tackle predictors of vitamin D status, favoring a healthier lifestyle and promoting supplementation in the groups at higher risk of hypovitaminosis D.

Vitamin D and PTH status among adolescent and young females with severe dysmenorrhea

OBJECTIVE

To investigate Vitamin D and parathyroid hormone (PTH) status among adolescent and young females with severe and very severe dysmenorrhea.

DESIGN

Cross-sectional study in specific selected sample.

SETTING

One Jordanian university.

PARTICIPANTS

Fifty-six females, ages between 17 and 24 years, with severe and very severe dysmenorrhea were surveyed regarding demographics, pain with menstruation, and dietary intake of dairy products. Plasma Vitamin D, PTH levels were measured.

RESULTS

About 61% of the studied population experience very severe dysmenorrhea. Half of participants had dairy intake less than 1 serving per day. The majority of participants (80%) had insufficient plasma vitamin D and 48% of them had hyperparathyroidism.

CONCLUSION

A high prevalence of vitamin D insufficiency and secondary hyperparathyroidism and/or low dietary calcium intake among adolescent and young adult females who experience severe and very severe dysmenorrhea may negatively affect bone metabolism during achievement of peak bone mass at a young age and adverse bone health at older age.

Recommended dietary intakes for vitamin D: Where do they come from, what do they achieve and how can we meet them?

There is substantial evidence that the prevalence of vitamin D deficiency is high across Europe, particularly, but not exclusively, among those resident at Northerly latitudes. This has significant implications for human health throughout the lifecycle and impacts upon healthy growth and development and successful ageing for current and possibly future generations. In recent years, there have been several important reports from North America and Europe in relation to dietary reference values (DRVs) for vitamin D. These may be of enormous value from a public health perspective in terms of preventing vitamin D deficiency and promoting adequate vitamin D status in the population. In this concise review, we provide a brief summary of current DRVs for vitamin D, their background and their application to vitamin D deficiency prevention. The review also provides some brief guidance with respect to applying the DRVs in a clinical nutrition setting. In addition, the review illustrates how current dietary intakes of most populations, young and adult, are well short of the newly established DRVs. Accordingly, the review highlights potential food-based or dietary strategies for increasing the distribution of vitamin D intake in the population with the aim of preventing vitamin D deficiency. Finally, despite the explosion in scientific research in vitamin D and health, there are many fundamental gaps in the field of vitamin D from the public health perspective. The impact of these knowledge gaps on current DRVs for vitamin D is highlighted, as are some future developments that may help address these gaps.

Seasonal variation of 25-hydroxyvitamin D among non-Hispanic black and white pregnant women from three US pregnancy cohorts

BACKGROUND

Vitamin D deficiency during pregnancy has been associated with increased risk of complications and adverse perinatal outcomes. We evaluated seasonal variation of 25-hydroxyvitamin D [25(OH)D] among pregnant women, focusing on patterns and determinants of variation.

METHODS

Data came from three cohort studies in the US that included 2583 non-Hispanic Black and White women having prenatal 25(OH)D concentrations determined. Fourier time series and generalised linear models were used to estimate the magnitude of 25(OH)D seasonality. We modelled seasonal variability using a stationary cosinor model to estimate the phase shift, peak-trough difference, and annual mean of 25(OH)D.

RESULTS

We observed a peak for 25(OH)D in summer, a nadir in winter, and a phase of 8 months, which resulted from fluctuations in 25(OH)D3 rather than 25(OH)D2. After adjustment for covariates, the annual mean concentrations and estimated peak-trough difference of 25(OH)D among Black women were 19.8 ng/mL [95% confidence interval (CI) 18.9, 20.5] and 5.8 ng/mL [95% CI 4.7, 6.7], and for non-Hispanic White women were 33.0 ng/mL [95% CI 32.6, 33.4] and 7.4 ng/mL [95% CI 6.0, 8.9].

CONCLUSIONS

Non-Hispanic Black women had lower average 25(OH)D concentrations throughout the year and smaller seasonal variation levels than non-Hispanic White women. This study's confirmation of 25(OH)D seasonality over a calendar year has the potential to enhance public health interventions targeted to improve maternal and perinatal outcomes.

Differential effects of different vitamin D replacement strategies in patients with diabetes

BACKGROUND

The optimal treatment regimen for correcting vitamin D insufficiency in diabetic patients has not been established.

METHODS

Two hundred and forty four adult diabetic patients with vitamin D insufficiency were enrolled to receive: Ergocalciferol (D2) 50,000 IU daily over 10 days (500,000 IU) followed by Calcichew D3 (calcium carbonate/Cholecalciferol) BID (~24,000 IU cholecalciferol/month) (ECC) (n=53); Cholecalciferol (D3) 40,000 IU daily over 10 days (400,000 IU) followed by Calcichew D3 BID (~24,000 IU cholecalciferol/month) (CCC) (n=94) or Cholecalciferol 40,000 IU daily over 10 days (400,000 IU) followed by Cholecalciferol 40,000 IU monthly (CC) (n=97). The 25(OH)D, HbA1c, lipids, blood pressure and eGFR were assessed at baseline and after a mean follow up of 8.0±4.0 months.

RESULTS

Treatment increased 25(OH)D concentrations significantly in ECC (17.4±13.8 vs 29.9±9.6 ng/ml, P<0.0001), CCC (14.2±6.6 vs 30.9±13.1 ng/ml, p<0.0001) and CC (13.5±8.4 vs 33.9±14.4 ng/ml, P<0.0001). The relative increase in 25(OH)D was significantly lower with ECC compared to CC (+14.6±12.2 vs +20.6±15.0, P=0.01) and the majority of subjects in the ECC group (63%) remained vitamin D deficient (25(OH)D <30 ng/ml) compared to CCC (46%) and CC (36%) (P=0.0005).

CONCLUSION

This study demonstrates that relatively aggressive treatment regimens of both vitamin D2 and D3 increase 25(OH)D concentrations in diabetic patients, but the ability to raise 25(OH)D status to 'sufficient' levels is inadequate in a large proportion of individuals.

Vitamin D status and predictors of hypovitaminosis D in Italian children and adolescents: a cross-sectional study

Hypovitaminosis D affects children and adolescents all around the world. Italian data on vitamin D status and risk factors for hypovitaminosis D during pediatric age are lacking. Six hundred fifty-two children and adolescents (range 2.0-21.0 years) living in the northwestern area of Tuscany were recruited at the Department of Pediatrics, University Hospital Pisa. None of them had received vitamin D supplementation in the previous 12 months. 25-hydroxyvitamin D (25-OH-D) and parathyroid hormone (PTH) levels were analyzed in all subjects. Severe vitamin D deficiency was defined as serum levels of 25-OH-D<25.0 nmol/L (10.0 ng/mL) and vitamin D deficiency a<50.0 nmol/L (20.0 ng/mL). Serum 25-OH-D levels of 50.0-74.9 nmol/L (20.0-29.9 ng/mL) indicated vitamin D insufficiency, whereas 25-OH-D levels ≥ 75.0 nmol/L (30.0 ng/mL) were considered sufficient. Hypovitaminosis D was defined as 25-OH-D levels<75.0 nmol/L (30.0 ng/mL). The median serum 25-OH-D level was 51.8 nmol/L, range 6.7-174.7 (20.7 ng/mL, range 2.7-70.0), with a prevalence of vitamin D deficiency, insufficiency, and sufficiency of 45.9, 33.6, and 20.5 %, respectively. The prevalence of severe vitamin D deficiency was 9.5 %. Adolescents had lower median 25-OH-D levels (49.8 nmol/L, range 8.1-174.7; 20.0 ng/mL, range 3.2-70.0) than children (55.6 nmol/L, range 6.8-154.6; 22.3 ng/mL, range 2.7-61.9, p=0.006). Non-white individuals (n=37) had median serum 25-OH-D levels in the range of deficiency (28.2 nmol/L, range 8.1-86.2; 11.3 ng/mL, range 3.2-34.5), with 36/37 having hypovitaminosis D. Logistic regression showed significant increased risk of hypovitaminosis D in the following: blood samples taken in winter (odds ratio (OR) 27.20), spring (OR 26.44), and fall (OR 8.27) compared to summer; overweight (OR 5.02) and obese (OR 5.36) subjects compared to individuals with normal BMI; low sun exposure (OR 8.64) compared to good exposure, and regular use of sunscreens (OR 7.06) compared to non-regular use. Gender and place of residence were not associated with vitamin D status. The 25-OH-D levels were inversely related to the PTH levels (r=-0.395, p<0.0001). Sixty-three out of the 652 (9.7 %) subjects showed secondary hyperparathyroidism.

CONCLUSION

Italian children and adolescents who were not receiving vitamin D supplementation had high prevalence of hypovitaminosis D. Careful identification of factors affecting vitamin D status is advisable to promptly start vitamin D supplementation in children and adolescents.

Vitamin D deficiency among newborns in Amman, Jordan

OBJECTIVE

Vitamin D deficiency is well recognized in selected Middle Eastern countries, but neonatal vitamin D status is not well studied in Jordan and other nearby countries. The aim of this study is to determine the prevalence of vitamin D deficiency in Jordanian newborns and risk factors associated with low levels.

METHODS

This is a prospective cohort study of newborn infants who were delivered at the Al Bashir Government Hospital in Amman, Jordan, from January 31, 2010, to January 27, 2011. Heel stick blood samples for 25-hydroxyvitamin D [25(OH)D] levels were obtained within 96 hours of birth. Maternal dress pattern, vitamin supplementation, smoke exposure during pregnancy, mode of delivery, gestational age, and birth weight were documented.

RESULTS

Samples were obtained from 3,731 newborns. Median gestational age was 39 weeks, median birth weight was 3.1 kilograms, median maternal age was 27 years, and median newborn 25(OH)D level was 8.6nmol/L. A total of 3,512 newborns (94.1%) in this study were vitamin D deficient (< 50 nmol/L). Lower gestational age, maternal smoke exposure, and birth during winter months were associated with lower infant vitamin D levels, while vitamin D supplementation and time spent outside during pregnancy were associated with higher vitamin D levels.

CONCLUSIONS

The prevalence of severely low vitamin D levels in newborn infants in Amman, Jordan, is substantial, even in newborns born during the spring and summer months. Vitamin D supplementation is needed in this population.

Measurement of circulating 25-hydroxy vitamin d using three commercial enzyme-linked immunosorbent assay kits with comparison to liquid chromatography: tandem mass spectrometry method

Aim. The purpose of this study was to compare the accuracy and clinical implications of three commercial enzyme-linked immunosorbent assay (ELISA) kits (Eagle Biosciences, Immundiagnostik, and MicroVue) with a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the measurement of serum 25(OH)D concentration. Methods. Blood samples were obtained from 225 healthy individuals who were recruited as subjects from Loughborough University, UK. Plasma samples were measured for 25(OH)D concentration by means of LC-MS/MS and ELISA kits from Eagle Biosciences, Immundiagnostik, and MicroVue. Results. The 25(OH)D concentration measured by the Eagle Biosciences, Immundiagnostik, and MicroVue ELISAs biased −50.9 ± 79.1 nmol/L, −14.2 ± 91.0 nmol/L, and −7.2 ± 18.9 nmol/L (bias ± SD) from the LC-MS/MS method, respectively. We found that 52% (Eagle Biosciences), 48% (Immundiagnostik), and 38% (MicroVue) of participants were misclassified, and the results showed the poor agreement (Kappa: −0.201~0.251) in classification of participants defined as vitamin D sufficiency and insufficiency between each method and LC-MS/MS. Conclusions. The present study demonstrated that there were negative biases and considerable misclassification of participants using the cut-off point (50 nmol/L) for vitamin D insufficiency and sufficiency using the Eagle Biosciences, Immundiagnostik, and MicroVue ELISAs compared with the LC-MS/MS assay.

Modelling vitamin D status due to oral intake and sun exposure in an adult British population

A mathematical model is described for estimating changes in plasma 25-hydroxyvitamin D (25(OH)D) levels throughout the year as a consequence of varying the oral intake of vitamin D and the behaviour outdoors of white British adults resident in different regions of the UK. The model yields seasonal and geographical patterns of 25(OH)D concentrations that agree closely with observational studies. Use of the model allows estimates to be easily made of the sun exposure and oral intake necessary to avoid vitamin D deficiency in defined proportions of the population, as well as strategies that would lead to vitamin D sufficiency throughout the year. The analysis demonstrates that addressing concerns about insufficient vitamin D levels, especially during the winter, may be achieved by modifying oral vitamin D intake over the winter, increasing summer sun exposure or a combination of both.

Effect of country of origin, age, and body mass index on prevalence of vitamin D deficiency in a US immigrant and refugee population

OBJECTIVE

To determine the prevalence of vitamin D deficiency (VDD) (25-hydroxyvitamin D level <20 ng/mL) and severe VDD (25[OH]D level <10 ng/mL) in a Minnesota immigrant and refugee population.

PATIENTS AND METHODS

This retrospective study evaluated a cohort of adult immigrants and refugees seen at Health Partners Center for International Health in St Paul, Minnesota. Study participants were all patients seen from August 1, 2008, through July 31, 2009, with a first vitamin D screen (N=1378). Outcomes included overall prevalence of VDD and severe VDD. Covariates included country of origin, sex, age, month of test, and body mass index (BMI).

RESULTS

Vitamin D deficiency was significantly more prevalent in our Minnesota clinic immigrant and refugee population than among US-born patients (827 of 1378 [60.0%] vs 53 of 151 [35.1%]; P<.001). Severe VDD was also significantly more prevalent (208 of 1378 [15.1%] vs 12 of 151 [7.9%]; P=.02). Prevalence of VDD varied significantly according to country of origin (42 of 128 Russian patients [32.8%] vs 126 of 155 Ethiopian patients [81.3%]; P<.001). The BMI correlated [corrected] with VDD (488 of 781 [62.5%] when BMI was ≥ 25 vs 292 of 520 [56.2%] when BMI was <25; P=.02). Vitamin D deficiency was present in 154 of 220 individuals (70.0%) 16 to 29 years old vs 123 of 290 (42.4%) in those older than 66 years (P<.001).

CONCLUSION

Immigrants and refugees in a Minnesota clinic have a substantially higher rate and severity of VDD when compared with a US-born population. Country of origin, age, and BMI are specific risk factors for VDD and should influence individualized screening practices.

Status of vitamin D in children with sickle cell disease living in Madrid, Spain

Patients with sickle cell disease have vitamin D deficiency and poor bone health which makes them prone to have an increased risk of fractures and osteoporosis in adulthood. We performed a prospective, cross-sectional study in children diagnosed with sickle cell disease living in Madrid, Spain. The purpose of this study was to evaluate the status of vitamin D of these children. Patients 0-16 years old were enrolled between 2008 and 2011. We studied demographics, calcium metabolism, and bone health, especially by measuring levels of 25-hydroxyvitamin D (25(OH)D), during different seasons of the year, and bone densitometry (beyond 4 years of age). Seventy-eight children were included in the study. Mean age was 4.8 ± 4.3 years, and mean serum 25(OH)D level was 21.50 ± 13.14 ng/ml, with no differences in 25(OH)D levels within different seasons. Fifty-six percent of children had levels of 25(OH) vitamin D of <20 ng/ml, whereas 79 and 18 % of them had levels of <30 and <11 ng/ml, respectively. Secondary hyperparathyroidism was observed in 25 % of children. Densitometry was performed in 33 children, and an abnormal z-score was seen in 15.2 % of them with no correlation with levels of 25(OH)D.

CONCLUSIONS

Vitamin D deficiency is highly prevalent in children with sickle cell disease, who are residing in Madrid, Spain, and it is detected at a young age. We propose that early intervention may increase the possibility of an adequate bone density later in life.