Seasonal and sex-related variation in vitamin D status and its association with other biochemical markers in young individuals: A cross-sectional study.

BACKGROUND: While several studies have investigated the association between vitamin D deficiency and biochemical parameters, the results are still inconsistent and mostly overlook seasonal variations. This study explored the relationships between 25-hydroxy-vitamin D (25(OH)D) concentrations, biochemical markers, and seasonal variation among young males and females. METHODS: A cross-sectional study was conducted among 203 individuals aged 18-24 years of both sexes residing in Brasilia, Brazil (latitude: 15°S). Sociodemographic variables, season of blood collection, and serum levels of 25(OH)D, total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides, glycated hemoglobin (HbA1c), glucose, insulin, hs-CRP, parathyroid hormone, ionized calcium, and alkaline phosphatase were included. Descriptive statistics and differences among groups, correlations, and linear regression tests were performed. RESULTS: The mean age of the participants was 21.17±1.7 years, and the mean serum 25(OH)D level was 25.76±7.0 ng/mL. Of the participants, 50.7% had vitamin D insufficiency (20 to 29.9 ng/mL), and 23.2% were vitamin D deficient (≤20 ng/mL). Vitamin D deficiency was higher in the spring (53.2%) and among females (29.5%). In young men with vitamin D insufficiency/deficiency (≤29.9 ng/mL) (n = 49), 25(OH)D levels were inversely correlated with HOMA-ß (r = -0.234, p = 0.032) and triglyceride (r = -0.415, p = 0.003) levels. However, there were no significant correlations between 25(OH)D concentrations and biochemical markers among women with insufficient and deficient vitamin D levels. CONCLUSION: This study found a high prevalence of vitamin D insufficiency/deficiency among young individuals living in Brasília, Brazil, particularly women and during the spring season. Our findings suggest that lower 25(OH)D levels (≤29.9 ng/mL) may be associated with insulin resistance and an increased risk of cardiovascular disease in young men studied. However, further studies with larger representative samples are needed to explore the mechanisms underlying the association between vitamin D and biochemical parameters.

Determinant factors of bone health after long-term of Roux-en-Y gastric bypass surgery: A cross-sectional study.

OBJECTIVES: The aim of this study was to evaluate bone health and the potential influencing factors of bone metabolism disorders in adults ≥5 y after Roux-en-Y gastric bypass (RYGB) surgery. METHODS: In this cross-sectional study, patients who were ≥5 y post-RYGB were invited. Bone health considered as bone mineral content (BMC) and bone mineral density (BMD) in this study was assessed by dual x-ray absorptiometry. We also assessed 25-hydroxy-vitamin D concentrations, individual ultraviolet B radiation levels, serum ionized calcium, alkaline phosphatase, parathyroid, anthropometric, and body composition. RESULTS: The study evaluated 104 adults (90% women; 49.6 ± 9.1 y old; postoperative period 8.7 ± 2.2 y). Lumbar and femoral BMC and BMD were positively correlated to body mass index (BMI), appendicular lean mass (ALM), and negatively to %excess of weight loss (EWL). Femoral BMD was negatively correlated to age, and both femoral BMD and BMC were positively correlated to weekly exposed body part score. Sex, age, BMI, ALM, and weekly exposed body part score explained 35% and 54% of the total variance of femoral BMD and BMC, respectively. CONCLUSIONS: The present findings suggested that older age, lower BMI, higher %EWL, lower ALM, and lower weekly body part exposure score are important determinants in lowering BMD and BMC parameters in long-term post-bariatric surgery individuals, rather than serum 25-hydroxy-vitamin D and parathyroid.

Vitamin D and musculoskeletal health: outstanding aspects to be considered in the light of current evidence.

Vitamin D enhances calcium absorption and bone mineralisation, promotes maintenance of muscle function, and is crucial for musculoskeletal health. Low vitamin D status triggers secondary hyperparathyroidism, increases bone loss, and leads to muscle weakness. The primary physiologic function of vitamin D and its metabolites is maintaining calcium homeostasis for metabolic functioning, signal transduction, and neuromuscular activity. A considerable amount of human evidence supports the well-recognised contribution of adequate serum 25-hydroxyvitamin D concentrations for bone homeostasis maintenance and prevention and treatment strategies for osteoporosis when combined with adequate calcium intake. This paper aimed to review the literature published, mainly in the last 20 years, on the effect of vitamin D and its supplementation for musculoskeletal health in order to identify the aspects that remain unclear or controversial and therefore require further investigation and debate. There is a clear need for consistent data to establish realistic and meaningful recommendations of vitamin D status that consider different population groups and locations. Moreover, there is still a lack of consensus on thresholds for vitamin D deficiency and optimal status as well as toxicity, optimal intake of vitamin D, vitamin D supplement alone as a strategy to prevent fractures and falls, recommended sun exposure at different latitudes and for different skin pigmentations, and the extra skeletal effects of vitamin D.

Association between vitamin D status and lifestyle factors in Brazilian women: Implications of Sun Exposure Levels, Diet, and Health.

Background: Vitamin D deficiency has been documented to be prevalent, even in low latitude regions; and this may be related to sun exposure behaviors. The aim of the current study was to assess the association between serum 25-hydroxyvitamin D [25(OH)D] concentrations and lifestyle-related factors in a sample of Brazilian women living at latitude 21º 8' S. Methods: A cross-sectional study was undertaken in 101 women aged 35 years or older in July 2019 to assess the association between 25(OH)D concentration and level of exposure to ultraviolet radiation (UVR), smoking habits, alcohol consumption, and physical activity levels. Age, body mass index (BMI), and postmenopausal status were investigated. Findings: According to the slope coefficient for individual daily UVR levels, the concentration of 25(OH)D increased by 5 nmol / L for each extra Standard Erythema Dose of UVR, regardless of age and BMI (p < 0·001). Postmenopausal women had a significantly higher mean concentration of 25(OH)D (p = 0·01), higher UVR exposure (p = 0·01) and lower BMI (p = 0·005) compared with younger women, independent of other confounders including smoking, alcohol, occupation and physical activity. Interpretation: Although postmenopausal women from Brazil had higher mean concentrations of 25(OH)D than younger women, more studies are necessary to understand how sun exposure and lifestyle variables interfere with these levels. These findings have important public health implications since they suggest that vitamin D deficiency in older age is not inevitable. Funding: This study was funded by an award received by Universities Global Partnership Network - UGPN. KVSS and SLO receive scholarship from CAPES, Brazilian Ministry of Education. HR receives a productivity grant from CNPq.

Frequency of Vitamin D Deficiency and Associated Factors in Long-term Bariatric Surgery Patients: a Cross-sectional Study.

BACKGROUND: Vitamin D deficiency is a common consequence of bariatric surgery (BS). However, few studies have evaluated influential factors and to date there are no studies investigating individual ultraviolet B (UVB) radiation levels in BS patients. This study aimed to evaluate vitamin D deficiency and its associated factors, including UVB radiation, in Roux-Y gastric bypass (RYGB) patients. METHODS: This study included 104 adults (90.4% female) at least 5 years after RYGB. Patients underwent surgery in private hospitals (Private; n = 47) or in two public hospitals, one with ongoing outpatient care (Active; n = 17), and the other with discontinued service for BS (Discontinued; n = 40). 25-hydroxyvitamin D (25(OH)D) concentrations were analyzed by chemiluminescence, individual UVB radiation levels by dosimeter badges. Vitamin D intake, anthropometric, skin phototype, sociodemographic and lifestyle patterns were also assessed. RESULTS: Mean age was 49.6 ± 9.1 years and post-operative period 8.7 ± 2.2 years. The prevalence of 25(OH)D deficiency and insufficiency was 25.0% and 51.9% respectively. 25(OH)D concentration differed among the hospitals (private = 26.2 ± 8.5; active = 28.7 ± 11.4; discontinued = 23.5 ± 6.5 ng/mL; p = 0.038). A total of 26.2% of the variance observed in 25(OH)D concentrations was explained by daily UVB radiation levels (ß = 0.224; p = 0.032) and vitamin D intake (ß = 0.431; p < 0.001), controlling for age and BMI. CONCLUSION: A quarter of the evaluated patients presented vitamin D deficiency, which was associated with the discontinuation of the health care, higher BMI, lower vitamin D intake, and lower individual UVB radiation levels.

Effects of Bifidobacterium animalis subspecies lactis supplementation on gastrointestinal symptoms: systematic review with meta-analysis.

CONTEXT: The effects of probiotics on gastrointestinal (GI) symptoms have been increasingly investigated, particularly that of Bifidobacterium animalis. Clinical trials so far have shown differing evidence regarding these effects in healthy adults. OBJECTIVE: To synthesize the published evidence on the effects of B. animalis subspecies lactis on GI symptoms (GIS) in healthy adults. DATA SOURCE: A search of the Medline, Embase, Lilacs, Scopus, Web of Science, ProQuest, and Google Scholar databases was conducted for reports on randomized controlled trials published up to October 2021. DATA EXTRACTION: Population characteristics and data on colonic transit time (CTT), stool consistency, defecation frequency, abdominal pain, bloating, flatulence, volunteer compliance, and adverse events were extracted. A random-effects model was used to estimate the effect of probiotic treatment on these variables. DATA SYNTHESIS: In total, 1551 studies were identified, of which 14 were included in the qualitative synthesis and 13 in the meta-analysis. Overall, probiotic supplementation increased defecation frequency (standardized mean difference [SMD], 0.26; 95%CI, 0.13-0.39). Subgroup analysis revealed a decrease in CTT (SMD, -0.34; 95%CI, -0.62 to -0.07) in short-term treatment (≤14 d) and an improvement in stool consistency (SMD, 0.76; 95%CI, 0.44-1.08) in individuals without GIS. No improvement in abdominal pain and bloating was found. CONCLUSIONS: B. animalis subspecies lactis supplementation may increase defecation frequency and, in short-term treatment, may reduce CTT in healthy adults and improve stool consistency in individuals without GIS. More high-quality randomized controlled trials are needed to develop a clinical protocol for the use of this strain to improve these symptoms. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. CRD42020154060.

Effect of multispecies probiotic on gut microbiota composition in individuals with intestinal constipation: A double-blind, placebo-controlled randomized trial.

OBJECTIVE: The aim of this study was to evaluate the effect of a multispecies probiotic on gut microbiota composition and constipation symptoms. METHODS: A randomized, double-blind, placebo-controlled clinical trial was conducted with 35 individuals with constipation for 30 days. The individuals were randomized into two groups: the control capsule (CC) and the probiotic capsule (PC) groups. Constipation symptoms were evaluated by the ROME IV criteria and by evacuation diaries. Fecal microbiota was analyzed by 16 S rRNA gene sequencing. RESULTS: The majority of participants were women (85.7%). There was a significant reduction in the percent of participants who had incomplete defecation (P = 0.034), blockage sensation (P = 0.025), and rarely present liquid stools without the aid of laxatives (P = 0.046) only within the PC group (but no significant difference between groups). There was a significant increase in the relative abundance percentage of Blautia faecis and Ruminococcus torques in the CC group (P = 0.003 and P = 0.011, respectively), although there was no significant change in the PC group (P = 0.794 and P = 0.958, respectively), with a significant difference between groups (P = 0.029 and P 0.013, respectively), suggesting that probiotic treatment prevented the increase of percent relative abundance of these two species. CONCLUSION: These results suggest that multispecies probiotics in capsule form may modulate gut microbiota by reducing the bacteria that are commonly increased in patients with constipation, contributing to the balance of microbiota and, consequently, to the well-being of the individual. Future studies with larger numbers of patients are required.

Does Vitamin D play a role in the management of Covid-19 in Brazil?

The study discusses the possible role of adequate vitamin D status in plasma or serum for preventing acute respiratory infections during the Covid-19 pandemic. Our arguments respond to an article, published in Italy, that describes the high prevalence of hypovitaminosis D in older Italian women and raises the possible preventive and therapeutic role of optimal vitamin D levels. Based on literature review, we highlight the findings regarding the protective role of vitamin D for infectious diseases of the respiratory system. However, randomized controlled trials are currently lacking. Adequate vitamin D status is obtained from sun exposure and foods rich in vitamin D. Studies in Brazil have shown that hypovitaminosis D is quite common in spite of high insolation. Authors recommend ecological, epidemiological and randomized controlled trials studies to verify this hypothesis.

Does vitamin D play a role in the management of Covid-19 in Brazil?

ABSTRACT The study discusses the possible role of adequate vitamin D status in plasma or serum for preventing acute respiratory infections during the Covid-19 pandemic. Our arguments respond to an article, published in Italy, that describes the high prevalence of hypovitaminosis D in older Italian women and raises the possible preventive and therapeutic role of optimal vitamin D levels. Based on literature review, we highlight the findings regarding the protective role of vitamin D for infectious diseases of the respiratory system. However, randomized controlled trials are currently lacking. Adequate vitamin D status is obtained from sun exposure and foods rich in vitamin D. Studies in Brazil have shown that hypovitaminosis D is quite common in spite of high insolation. Authors recommend ecological, epidemiological and randomized controlled trials studies to verify this hypothesis.