A Narrative Review of The Role of Foods as Dietary Sources of Vitamin D of Ethnic Minority Populations with Darker Skin: The Underestimated Challenge

A systematic literature review and meta-analysis of the effectiveness of vitamin D supplementation for patients with Duchenne muscular dystrophy

We conducted a systematic literature review and meta-analysis on the effectiveness of vitamin D supplementation in maintaining or restoring vitamin D levels in Duchenne muscular dystrophy. Due to a lack of randomised controlled trials, cross-sectional and retrospective and prospective cohort studies were taken as the best available evidence. Inclusion criteria included reporting mean serum vitamin D levels in a supplement-taking group. After screening 102 records; 13 were included in a narrative synthesis and eight of these in a meta-analysis. We show that current dosing regimens are preventing severe deficiency but are not effective at maintaining sufficient vitamin D levels within the Duchenne population. Despite high levels of daily vitamin D supplementation (>1000 International Units), at least 20 % of people with Duchenne remain vitamin D deficient. No significant association between dose and serum vitamin D levels was found (r2 = 0.3, p = 0.237). A meta-analysis of mean serum vitamin D levels across eight studies also revealed substantial variability in response to vitamin D supplementation and high heterogeneity (I2 = 99.59 %). These data could impact on an individual's risk and severity of osteoporosis and vertebral fractures.

A role for vitamin D and the vitamin D receptor in keloid disorder

Keloids are disfiguring fibroproliferative lesions that can occur in susceptible individuals following any skin injury. They are extremely challenging to treat, with relatively low response rates to current therapies and high rates of recurrence after treatment. Although several distinct genetic loci have been associated with keloid formation in different populations, there has been no single causative gene yet identified and the molecular mechanisms guiding keloid development are incompletely understood. Further, although it is well known that keloids are more commonly observed in populations with dark skin pigmentation, the basis for increased keloid risk in skin of colour is not yet known. Because individuals with dark skin pigmentation are at higher risk for vitamin D deficiency, the role of vitamin D in keloid pathology has gained interest in the keloid research community. A limited number of studies have found lower serum vitamin D levels in patients with keloids, and reduced expression of the vitamin D receptor (VDR) in keloid lesions compared with uninjured skin. Vitamin D has documented anti-inflammatory, anti-proliferative and pro-differentiation activities, suggesting it may have a therapeutic role in suppression of keloid fibrosis. Here we review the evidence supporting a role for vitamin D and VDR in keloid pathology.

Bioavailability of vitamin D biofortified pork meat: results of an acute human crossover study in healthy adults

Vitamin D intakes are concerningly low. Food-based strategies are urgently warranted to increase vitamin D intakes and subsequently improve 25-hydroxyvitamin D (25(OH)D) concentrations. This acute randomised three-way crossover study investigated the efficacy of vitamin D biofortified pork derived from pigs exposed to UVB light to increase serum 25(OH)D₃ concentrations, compared to a dose-matched vitamin D₃ supplement and control pork in adults (n = 14). Blood samples were obtained at baseline and then 1.5, 3, 6, 9 and 24 h postprandially. There was a significant effect of time (p < 0.01) and a significant treatment*time interaction (p < 0.05). UV pork and supplement significantly increased within-group serum 25(OH)D₃ concentrations over timepoints (p < 0.05) (max. change 0.9 nmol/L (2.2%) UV pork, 1.5 nmol/L (3.5%) supplement, 0.7 nmol/L (1.9%) control). Vitamin D biofortified pork modestly increased 25(OH)D₃ concentrations and produced a similar response pattern as a dose-matched vitamin D supplement, but biofortification protocols should be further optimised to ensure differentiation from standard pork.

Predictors of Vitamin D Insufficiency in Children and Adolescents With Alopecia Areata

Introduction: Limited data regarding predictors of vitamin D deficiency in US children exist. We aimed to identify predictors of vitamin D insufficiency among children with alopecia areata.

Methods: The medical records of 439 pediatric patients diagnosed with alopecia areata (AA) between January 2015 and December 2017 were reviewed. Those with 25-hydroxyvitamin D levels and no documented vitamin supplementation, chronic illness, or other autoimmune comorbidities other than AA were included. Demographic data, Fitzpatrick skin type, and the month of blood collection were recorded. Monthly UV index information from Philadelphia, PA corresponding to the month of blood collection was also collected.

Results: Within our cohort, 60.4% of patients had insufficient vitamin D levels, of which 38.2% were deficient. The mean age was nine years old. In multivariate analyses, higher Fitzpatrick skin type, non-summer season, and non-White race were associated with vitamin D insufficiency, while the monthly UV index was inversely associated.

Discussion/Conclusion: Higher Fitzpatrick skin type, non-summer season, and non-White race may be associated with vitamin D insufficiency in US pediatric patients. Larger studies are warranted to replicate our findings and fully evaluate predictors of pediatric vitamin D deficiency in the US.

Effect of Selected Factors on the Serum 25(OH)D Concentration in Women Treated for Breast Cancer

Maintaining an optimal vitamin D concentration reduces the risk of recurrence and extends survival time in patients after breast cancer treatment. Data on vitamin D deficiency among Polish women after breast cancer therapy are limited. Thus, the aim of the study was the analysis of vitamin D status in post-mastectomy patients, considering such factors as seasons, social habits, vitamin D supplementation and its measurements. The study involved 94 women after breast cancer treatment. Serum vitamin D concentration was measured, and a questionnaire, gathering demographic and clinical data regarding cancer, diet, exposure to sun radiation, and knowledge of recommendations on vitamin D supplementation, was delivered twice, in both winter and in summer. The control group consisted of 94 age-matched women with no oncological history. In women after breast cancer treatment, 25-hydroxyvitamin D (25(OH)D) deficiency was much more frequent than in the general population. Only about half of the patients supplemented vitamin D at the beginning of the study. After the first test and the issuing of recommendations on vitamin D supplementation, the percentage of vitamin D supplemented patients increased by about 30% in study groups. The average dose of supplement also increased. None of the women that were not supplementing vitamin D and were tested again in winter had optimal 25(OH)D concentration. It was concluded that vitamin deficiency is common in women treated for breast cancer. Medical advising about vitamin D supplementation and monitoring of 25(OH)D concentration should be improved.

Gender-Dependent Association of Vitamin D Deficiency with Obesity and Hypercholesterolemia (LDLC) in Adults

BACKGROUND

Obesity, dyslipidemia and vitamin D deficiency are growing health problems in the Arabian Gulf region. Their association with each other is yet to be clarified.

METHODS

Three-hundred and fourteen Bahraini adults, 164 males and 150 females comparable in median age (34.5 vs. 31.0 yrs), body mass index (BMI), and ethnicity were recruited. The plasma level of 25-hydroxyvitamin D3 (25OHD3) was measured by chemiluminescent immunoassay and lipid profile parameters were measured by an automated clinical chemistry analyzer. Based on BMI, study subjects were grouped into underweight, normal, overweight, moderate obesity, and severe obesity subjects.

RESULTS

The results revealed an extremely high prevalence of vitamin D deficiency (79.9%) and insufficiency (18.8%). The predictors of low 25OHD3 levels were female gender, small age, conservative dressing, least exposure to sunlight, and less fish intake. In all subjects, the lowest 25OHD3 level was seen in underweight and severe obesity groups. Furthermore, the 25OHD3 level was significantly higher in males as compared to females and it was positively correlated with the age. However, detailed analysis showed that overweight males unlike females had the highest 25OHD3 levels which were significantly higher than in the severely obese males. While the lipid profile parameters were positively correlated with BMI, the total and LDL cholesterols were negatively correlated with the levels of 25OHD3 in males.

CONCLUSION

Vitamin D deficiency was associated with both severely obese and underweight subjects, in the former it was likely to be institutional while in the latter it was likely to be nutritional. Furthermore, hypercholesterolemia (LDL-C) was associated with 25OHD3 sub-normality. Further analysis revealed that the significant associations were gender-dependent.

Dietary Interventions for Treatment of Chronic Pain: Oxidative Stress and Inflammation

Chronic pain is highly prevalent in the United States, impacting 28.4% of the adult population, or 69.6 million people, as of 2016. Chronic pain is often associated with anxiety, depression, and restrictions in mobility and daily activities, substantially reducing quality of life. Analgesics, especially opioids, are one of the primary pharmaceutical treatment methods for chronic pain. However, prescription opioid misuse and abuse has become increasingly prevalent and concerning, prompting the need for research into alternative treatment methods which avoid the side effects of traditional treatments. Chronic pain is, in part, thought to be the result of oxidative stress and inflammation, and clinical research has indicated links between these conditions and diet. Thus, dietary interventions are a particularly promising therapeutic treatment for chronic pain, with numerous studies suggesting that diet has a noticeable effect on pain as far down as the cellular level. In this review article, data from a number of clinical trials assessing the effect of three diets—antioxidant-rich, low-carbohydrate, and Mediterranean—on oxidative stress and inflammation is compiled and discussed in the context of chronic pain. Clinical data suggests that low-carbohydrate diets and Mediterranean diets both are especially promising dietary interventions.

Vitamin D status in patients with systemic lupus erythematosus (SLE): A systematic review and meta-analysis

BACKGROUND

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease where chronic inflammation and tissue or organ damage is observed. Due to various suspected causes, inadequate levels of vitamin D (a steroid hormone with immunomodulatory effects) has been reported in patients with SLE, however, contradictory.

AIMS

The aim of this systematic review and meta-analysis was to evaluate the serum levels of vitamin D in patients with SLE in compared to healthy controls.

METHODS

PubMed, SCOPUS, ScienceDirect and Google Scholar electronic databases were searched systematically without restricting the languages and year (up to March 2, 2019) and studies were selected based on the inclusion criteria. Mean difference (MD) along with 95% confidence intervals (CI) were used and the analyses were carried out by using a random-effects model. Different subgroup and sensitivity analyses were conducted. Study quality was assessed by the modified Newcastle-Ottawa Scale (NOS) and publication bias was evaluated by a contour-enhanced funnel plot, Begg's and Egger's tests.

RESULTS

We included 34 case-control studies (2265 SLE patients and 1846 healthy controls) based on the inclusion criteria. Serum levels of vitamin D was detected significantly lower in the SLE patients than that in the healthy controls (MD: -10.44, 95% CI: -13.85 to -7.03; p < .00001). SLE patients from Asia (MD: -13.75, 95% CI: -21.45 to -6.05; p = .0005), South America (MD: -3.16, 95% CI: -4.62 to -1.70; p < .0001) and Africa (MD: -16.15, 95% CI: -23.73 to -8.56; p < .0001); patients residing below 37° latitude (MD: -11.75, 95% CI: -15.79 to -7.70; p < .00001); serum vitamin D during summer season (MD: -7.89, 95% CI: -11.70 to -4.09; p < .0001), patients without vitamin D supplementation (MD: -15.57, 95% CI: -19.99 to -11.14; p < .00001) or on medications like hydroxychloroquine, corticosteroids or immunosuppressants without vitamin D supplementation (MD: -16.46, 95% CI: -23.86 to -9.05; p < .0001) are in higher risk in presenting inadequate serum levels of vitamin D. The results remained statistically significant from different sensitivity analyses which represented the robustness of this meta-analysis. According to the NOS, 91.2% of the studies were considered as of high methodological quality (low risk of bias). No significant publication bias was detected from contour-enhanced and trim and fill funnel plots or Begg's test.

CONCLUSION

Inadequate levels of serum vitamin D is significantly high in patients with SLE compared to healthy subjects, therefore, vitamin D supplementation with regular monitoring should be considered as part of their health management plans.

Vitamin D and Cardio-Metabolic Risk Factors in Overweight Adults: An Overview of the Evidence

BACKGROUND

Several studies have suggested a potential association between low vitamin D serum levels and several pathological conditions apart from the well-known bone disorders. Thus, vitamin D insufficiency has been linked to cardiometabolic risk factors including obesity, insulin resistance, hypertension, dyslipidemia, as well as type 2 diabetes and cardiovascular disease.

OBJECTIVE

This review intends to provide an overview of recent evidence from clinical studies on vitamin D [25- hydroxyvitamin D (25(OH)D)] and cardiometabolic risk factors in overweight adults. Furthermore, we also discussed potential mechanisms and limits of the retrieved results.

METHODS

The search process was based on the selection of publications (RCT) listed in PubMed and Cochrane Library databases.

RESULTS

Vitamin D status evidenced an inversely strong association with subcutaneous adipose tissue and visceral adiposity, but not significantly related to other bodyweight measures (i.e., body mass index). Studies have shown a potential inverse association of hypovitaminosis D with insulin resistance and cardiovascular risk factors.

CONCLUSION

The mechanisms by which vitamin D deficiency enhances adiposity, as well as putative association with metabolic syndrome features, remain still unclear. Further investigation would be required to conclude whether vitamin D has an independent role in preventing cardiometabolic disorders.

Perceived Correspondence of Health Effects as a New Determinant Influencing Purchase Intention for Functional Food

This study has revealed the role of a new factor, perceived correspondence of health effects, in consumer acceptance of functional foods. Using a web survey of 1016 people, we hypothesized and verified the following: when an ingredient does not occur naturally in the carrier but the consumer assigns the same health effect to it as to the carrier, the product’s acceptance will be more positive than it would be if an identical health effect was not associated with the carrier and the functional ingredient. Factors influencing consumer acceptance were examined via binary logistic regression models. According to the results, if a functional food developer fortifies the carrier with an ingredient that does not occur naturally in the carrier, the product can expect higher acceptance if the health effects perceived by consumers are properly matched. In general, it has been found that expected taste and awareness of the product were decisive in all demographic and income groups, whereas perceived correspondence of health effects had a lesser, but still positive influence on acceptance.