-
1.
Effect of Vitamin D3 Supplementation on Acute Fracture Healing: A Phase II Screening Randomized Double-Blind Controlled Trial.
Slobogean, GP, Bzovsky, S, O'Hara, NN, Marchand, LS, Hannan, ZD, Demyanovich, HK, Connelly, DW, Adachi, JD, Thabane, L, Sprague, S
JBMR plus. 2023;7(1):e10705
-
-
-
-
Free full text
Plain language summary
Almost half of all adult patients with fractures are vitamin D deficient. The aim of this double-blind, randomised, placebo-controlled trial was to evaluate the efficacy of different vitamin D regimens on the healing of acute tibia and femur fractures. 102 18-50-year-old patients were enrolled in the study and randomised to receive a) two high doses (150,000 IU) at time of injury and after 6 weeks, b) 4000 IU daily, c) 600 IU daily or d) placebo for 3 months. After 3 months, there were no statistically significant differences between the 3 intervention groups with respect to clinical or radiographic outcomes of fracture healing. The authors report a significantly better clinical, but not radiographic, outcome for 4000 IU per day versus placebo with a p-value of 0.15 (note: generally, to be considered statistically significant, p should be < 0.05). Similar results were observed after 12 months. There was no significant correlation between vitamin D levels and fracture healing. The authors concluded that high dose vitamin D may confer a modest benefit for fracture healing but that this requires confirmation from a larger clinical trial.
Expert Review
Conflicts of interest:
None
Take Home Message:
- The evidence base for the use of vitamin D supplements in isolation to support fracture healing is weak.
Evidence Category:
-
X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
-
B: Systematic reviews including RCTs of limited number
-
C: Non-randomized trials, observational studies, narrative reviews
-
D: Case-reports, evidence-based clinical findings
-
E: Opinion piece, other
Summary Review:
Introduction
- Low levels of vitamin D can have negative effects on bone metabolism and healing of fractures
- Almost half of all adult fracture patients are vitamin D deficient
- The aim of this study was to evaluate the effectiveness of supplementing vitamin D3 (VD3) to improve tibia and femur fracture healing.
Methods
- Four-arm, double-blind, randomised, phase II screening, placebo-controlled trial
- 102 adult patients (aged 18-50 years) with a non-osteoporotic tibial or femoral shaft fracture were randomised into 1 of 4 treatment groups
- Just over half (56%) of participants were vitamin D3 deficient at baseline
- Intervention groups: 1) 150,000 IU VD3 loading dose at injury and at 6 weeks (high loading) plus daily placebo; 2) placebo loading doses plus 4000 IU VD3 daily (high dose); 3) placebo loading doses plus 600 IU VD3 daily (low dose); 4) placebo loading dose plus placebo daily
- Duration: 3 months intervention, further 9 months follow-up. Vitamin D levels were assessed at 6 weeks and 3 months.
Primary outcome measures at 3 months:
- Clinical assessment using the Function IndeX for Trauma (FIX-IT)
- Radiographic assessment using the Radiographic Union Score for Tibial fractures (RUST).
Secondary outcomes: as above at 6, 9 and 12 months.
Results at 3 months:
- No statistically significant difference between high loading and high dose, high and low dose or low dose and placebo for either clinical or radiological assessment (all p-values ≥0.4)
- Post-hoc analysis of any dose vs placebo showed no significant difference with either clinical or radiological assessment (all p-values ≥0.25)
- Post-hoc analysis of high dose vs placebo showed no significant difference for radiological assessment (p=0.76) whilst it was reported as statistically significant for clinical assessment with p=0.16, with a benefit of VD3 supplementation.
- Similar results were seen at 12 months with reported benefit of high dose VD3 for fracture healing with p=0.18
- Vitamin D levels improved in all 3 VD3 groups from baseline to 6 weeks
- There was no statistically significant correlation between fracture healing and vitamin D level.
Conclusion
The authors conclude that VD3 supplementation may be of modest benefit for fracture healing, but further, larger trials are needed to confirm this.
Clinical practice applications:
- When working with clients who present with a fracture, it should be noted that the evidence for benefit of vitamin D supplementation alone for fracture healing is weak.
Considerations for future research:
- Larger studies to increase the statistical power to detect smaller benefits are required
- Larger studies may also identify differences in potential benefits between patient populations with different baseline levels of vitamin D.
Abstract
Nearly half of adult fracture patients are vitamin D deficient (serum 25-hydroxyvitamin D [25(OH)D] levels <20 ng/mL). Many surgeons advocate prescribing vitamin D supplements to improve fracture healing outcomes; however, data supporting the effectiveness of vitamin D3 supplements to improve acute fracture healing are lacking. We tested the effectiveness of vitamin D3 supplementation for improving tibia and femur fracture healing. We conducted a single-center, double-blinded phase II screening randomized controlled trial with a 12-month follow-up. Patients aged 18-50 years receiving an intramedullary nail for a tibia or femoral shaft fracture were randomized 1:1:1:1 to receive (i) 150,000 IU loading dose vitamin D3 at injury and 6 weeks (n = 27); (ii) 4000 IU vitamin D3 daily (n = 24); (iii) 600 IU vitamin D3 daily (n = 24); or (iv) placebo (n = 27). Primary outcomes were clinical fracture healing (Function IndeX for Trauma [FIX-IT]) and radiographic fracture healing (Radiographic Union Score for Tibial fractures [RUST]) at 3 months. One hundred two patients with a mean age of 29 years (standard deviation 8) were randomized. The majority were male (69%), and 56% were vitamin D3 deficient at baseline. Ninety-nine patients completed the 3-month follow-up. In our prespecified comparisons, no clinically important or statistically significant differences were detected in RUST or FIX-IT scores between groups when measured at 3 months and over 12 months. However, in a post hoc comparison, high doses of vitamin D3 were associated with improved clinical fracture healing relative to placebo at 3 months (mean difference [MD] 0.90, 80% confidence interval [CI], 0.08 to 1.79; p = 0.16) and within 12 months (MD 0.89, 80% CI, 0.05 to 1.74; p = 0.18). The study was designed to identify potential evidence to support the effectiveness of vitamin D3 supplementation in improving acute fracture healing. Vitamin D3 supplementation, particularly high doses, might modestly improve acute tibia or femoral shaft fracture healing in healthy adults, but confirmatory studies are required. The Vita-Shock trial was awarded the Orthopaedic Trauma Association's (OTA) Bovill Award in 2020. This award is presented annually to the authors of the most outstanding OTA Annual Meeting scientific paper. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
-
2.
Individual risk management strategy and potential therapeutic options for the COVID-19 pandemic.
Gasmi, A, Noor, S, Tippairote, T, Dadar, M, Menzel, A, Bjørklund, G
Clinical immunology (Orlando, Fla.). 2020;215:108409
-
-
-
Free full text
-
Plain language summary
With the continuing spread of COVID-19 and lack of any approved treatments, this paper examines possible strategies for prevention. The data emerging so far highlights that individual health status plays a critical role in determining clinical severity of COVID-19 symptoms ranging from asymptomatic, mild, moderate, to death. Metabolic status, as determined by a patient’s diet, nutrition, age, sex, medical conditions, lifestyle, and environmental factors can therefore be considered preventative strategies to improve the severity of COVID-19 outcomes. Social distancing and personal hygiene are stated as the most effective strategies to prevent or slow spread of the disease. However individual health status, age and the presence of pre-existing comorbidities influences outcomes, as shown by global data highlighting a prevalence in older, males with metabolic conditions; hypertension in 23.7% patients and diabetes in 16.2% of patients. Older males appear more prone to infectious diseases with high pro-inflammatory immune responses and low adaptive immune responses than an older woman. Diet and healthy intestinal and respiratory tract microbiota may also influence immune system competence. Numerous micronutrients are essential for immunocompetence, particularly vitamin A, C, D, E, Bs, iron, selenium, and zinc. A balanced diet, high in colourful fruits and vegetables with a variation of prebiotic fibres, probiotics, and plant polyphenols and phytonutrients, help promote a healthy, diverse microbiota. Oral probiotics may also be beneficial to vulnerable individuals. Vitamin D supplementation is also proving helpful in prevention of acute respiratory tract infections. Other lifestyle factors such as smoking and exposure to environmental toxins should also be considered. Together these preventative measures may reduce personal risk of getting the disease.
Abstract
It is an ugly fact that a significant amount of the world's population will contract SARS-CoV-II infection with the current spreading. While a specific treatment is not yet coming soon, individual risk assessment and management strategies are crucial. The individual preventive and protective measures drive the personal risk of getting the disease. Among the virus-contracted hosts, their different metabolic status, as determined by their diet, nutrition, age, sex, medical conditions, lifestyle, and environmental factors, govern the personal fate toward different clinical severity of COVID-19, from asymptomatic, mild, moderate, to death. The careful individual assessment for the possible dietary, nutritional, medical, lifestyle, and environmental risks, together with the proper relevant risk management strategies, is the sensible way to deal with the pandemic of SARS-CoV-II.
-
3.
Effectiveness of Vitamin D Supplementation in the Management of Multiple Sclerosis: A Systematic Review.
Berezowska, M, Coe, S, Dawes, H
International journal of molecular sciences. 2019;20(6)
-
-
-
Free full text
Plain language summary
Epidemiological research shows that Vitamin D status is associated with reduced activity and progression of disease in multiple sclerosis (MS). This review assessed the evidence from ten double-blind randomised controlled trials, including a total of 627 adults with relapsing remitting MS (RRMS), for the clinical effectiveness of vitamin D supplementation compared to placebo in disease and symptom management. The results from the reviewed studies on disease progression and immunological blood parameters were mixed. Where benefits of vitamin D supplementation were seen this tended to be in those groups where vitamin D levels were low at the start of the study. Those studies evaluating the safety and tolerability of vitamin D reported no serious adverse events. The authors conclude that baseline serum vitamin D levels may be a predictor of improvements in RRMS with vitamin D supplementation, and that further research should include baseline vitamin D as part of the assessment.
Abstract
OBJECTIVE to examine the extent of effect vitamin D in Multiple Sclerosis (MS) on pathology and symptoms. METHODS A literature search was performed in November 2018 (CRD42018103615). Eligibility criteria: randomised control trials in English from 2012 to 2018; a clinical diagnosis of MS; interventions containing vitamin D supplementation (vitamin D3 or calcitriol) in disease activity compared to a control/placebo; improvement in: serum 25(OH)D, relapse rates, disability status by Expanded Disability Status Scale (EDSS) scores, cytokine profile, quality of life, mobility, T2 lesion load and new T2 or T1 Gd enhancing lesions, safety and adverse effects. Risk of bias was evaluated. RESULTS Ten studies were selected. The study size ranged from 40 to 94 people. All studies evaluated the use of vitamin D supplementation (ranging from 10 to 98,000 IU), comparing to a placebo or low dose vitamin D. The duration of the intervention ranged from 12 to 96 weeks. One trial found a significant effect on EDSS score, three demonstrated a significant change in serum cytokines level, one found benefits to current enhancing lesions and three studies evaluating the safety and tolerability of vitamin D reported no serious adverse events. Disease measures improved to a greater extent overall in those with lower baseline serum 25(OH)D levels. CONCLUSIONS As shown in 3 out of 10 studies, improvement in disease measures may be more apparent in those with lower baseline vitamin D levels.
-
4.
Vitamin D Supplementation in Central Nervous System Demyelinating Disease-Enough Is Enough.
Häusler, D, Weber, MS
International journal of molecular sciences. 2019;20(1)
-
-
-
Free full text
Plain language summary
Vitamin D is associated with a reduced risk and severity of multiple sclerosis (MS). However, whether supplementing vitamin D level alters disease severity, is a matter of ongoing debate. This review looks at both clinical and pre-clinical evidence for supplementing vitamin D in people with MS. In vitro experiments show that vitamin D and its metabolites can alter function of various immune cells, mostly via interaction with vitamin D receptors (VDR). Results from human clinical trials, however, are mixed. Preclinical evidence suggests that high dose vitamin D supplementation, when leading to hypercalcaemia, a potentially serious side effect of excessive vitamin D intake, may worsen MS. The authors also review research which suggests mechanisms by which sun exposure can improve MS symptoms independent of vitamin D production. The authors conclude that moderate sun exposure, combined with adequate dietary intake of vitamin D, and in conjunction with a regular assessment of vitamin D serum levels (to avoid hypercalcaemia), might be the best strategy for patients with MS.
Abstract
The exact cause of multiple sclerosis (MS) remains elusive. Various factors, however, have been identified that increase an individual's risk of developing this central nervous system (CNS) demyelinating disease and are associated with an acceleration in disease severity. Besides genetic determinants, environmental factors are now established that influence MS, which is of enormous interest, as some of these contributing factors are relatively easy to change. In this regard, a low vitamin D status is associated with an elevated relapse frequency and worsened disease course in patients with MS. The most important question, however, is whether this association is causal or related. That supplementing vitamin D in MS is of direct therapeutic benefit, is still a matter of debate. In this manuscript, we first review the potentially immune modulating mechanisms of vitamin D, followed by a summary of current and ongoing clinical trials intended to assess whether vitamin D supplementation positively influences the outcome of MS. Furthermore, we provide emerging evidence that excessive vitamin D treatment via the T cell-stimulating effect of secondary hypercalcemia, could have negative effects in CNS demyelinating disease. This jointly merges into the balancing concept of a therapeutic window of vitamin D in MS.
-
5.
Impact of Vitamin D Supplementation on Influenza Vaccine Response and Immune Functions in Deficient Elderly Persons: A Randomized Placebo-Controlled Trial.
Goncalves-Mendes, N, Talvas, J, Dualé, C, Guttmann, A, Corbin, V, Marceau, G, Sapin, V, Brachet, P, Evrard, B, Laurichesse, H, et al
Frontiers in immunology. 2019;10:65
-
-
-
Free full text
Plain language summary
This randomized placebo-controlled double-blind trial investigated whether Vit-D supplementation in a sample of 38 deficient elderly persons, over 65-year olds, could improve influenza seroprotection and immune response. Vitamin D is known to both potentiate the innate immune response and inhibit the adaptive system, and so potentially modulate vaccination response. The participants were randomised into two arms: vitamin D supplementation group (D) and placebo group (P). The D group received 100,000 IU/15 days of cholecalciferol over a 3-month period after which both groups were given the influenza vaccine, and their blood was evaluated 28 days later. Several immune biomarkers were analysed including plasma cytokine profiles, phagocyte ROS production, and lymphocyte cells phenotyping to determine if Vitamin D enhanced immune response to the vaccination. No differences were found in serum ROS and antibody markers. However, Vitamin D supplementation did promote a higher TGFβ plasma level in response to influenza vaccination. Taken together, these results suggest that vitamin D supplementation is not an effective way to improve antibody response to influenza vaccine in deficient elderly people.
Abstract
Background: Immunosenescence contributes to reduced vaccine response in elderly persons, and is worsened by deficiencies in nutrients such as Vitamin (Vit-D). The immune system is a well-known target of Vit-D, which can both potentiate the innate immune response and inhibit the adaptive system, and so modulate vaccination response. Objective: This randomized placebo-controlled double-blind trial investigated whether Vit-D supplementation in deficient elderly persons could improve influenza seroprotection and immune response. Design: Deficient volunteers (Vit-D serum <30 ng/mL) were assigned (V1) to receive either 100,000 IU/15 days of cholecalciferol (D, n = 19), or a placebo (P, n = 19), over a 3 month period. Influenza vaccination was performed at the end of this period (V2), and the vaccine response was evaluated 28 days later (V3). At each visit, serum cathelicidin, immune response to vaccination, plasma cytokines, lymphocyte phenotyping, and phagocyte ROS production were assessed. Results: Levels of serum 25-(OH)D increased after supplementation (D group, V1 vs. V2: 20.7 ± 5.7 vs. 44.3 ± 8.6 ng/mL, p < 0.001). No difference was observed for serum cathelicidin levels, antibody titers, and ROS production in D vs. P groups at V3. Lower plasma levels of TNFα (p = 0.040) and IL-6 (p = 0.046), and higher ones for TFGβ (p = 0.0028) were observed at V3. The Th1/Th2 ratio was lower in the D group at V2 (D: 0.12 ± 0.05 vs. P: 0.18 ± 0.05, p = 0.039). Conclusions: Vit-D supplementation promotes a higher TGFβ plasma level in response to influenza vaccination without improving antibody production. This supplementation seems to direct the lymphocyte polarization toward a tolerogenic immune response. A deeper characterization of metabolic and molecular pathways of these observations will aid in the understanding of Vit-D's effects on cell-mediated immunity in aging. This clinical trial was registered at clinicaltrials.gov as NCT01893385.
-
6.
Daily Nutritional Supplementation with Vitamin D₃ and Phenylbutyrate to Treatment-Naïve HIV Patients Tested in a Randomized Placebo-Controlled Trial.
Ashenafi, S, Amogne, W, Kassa, E, Gebreselassie, N, Bekele, A, Aseffa, G, Getachew, M, Aseffa, A, Worku, A, Hammar, U, et al
Nutrients. 2019;11(1)
-
-
-
Free full text
Plain language summary
Poor nutritional status is common among human immunodeficiency virus (HIV)-infected patients including vitamin D (vitD3) deficiency. VitD3 together with phenylbutyrate (PBA) can induce an antimicrobial peptide called cathelicidin which has anti-viral properties. VitD3 and PBA can also enhance autophagy, a physiological process known to enhance destruction of intracellular viruses. The aim of this double-blind, placebo-controlled trial was to evaluate whether vitD3 + PBA could reduce viral replication and restore immune and nutritional status in HIV infection. 173 previously untreated HIV patients were randomised to receive either 5000 IU vitD3 and 500 mg PBA or placebos for 16 weeks with follow-up of a further 8 weeks. Most subjects had low plasma vitD3 levels at baseline which increased significantly in the vitD3 + PBA group compared with placebo at weeks 4, 8 and 16, indicating good compliance and response to the treatment. There were no statistical differences in any of the measured outcomes, including viral load, CD4 cells, CD8 cells and body mass index, between treatment and placebo group at any point during the study and follow-up.
Abstract
Poor nutritional status is common among human immunodeficiency virus (HIV)-infected patients including vitamin D (vitD₃) deficiency. We conducted a double-blinded, randomized, and placebo-controlled trial in Addis Ababa, Ethiopia, to investigate if daily nutritional supplementation with vitD₃ (5000 IU) and phenylbutyrate (PBA, 2 × 500 mg) could mediate beneficial effects in treatment-naïve HIV patients. Primary endpoint: the change in plasma HIV-1 comparing week 0 to 16 using modified intention-to-treat (mITT, n = 197) and per-protocol (n = 173) analyses. Secondary endpoints: longitudinal HIV viral load, T cell counts, body mass index (BMI), middle-upper-arm circumference (MUAC), and 25(OH)D₃ levels in plasma. Baseline characteristics were detectable viral loads (median 7897 copies/mL), low CD4⁺ (median 410 cells/µL), and elevated CD8⁺ (median 930 cells/µL) T cell counts. Most subjects were vitD₃ deficient at enrolment, but a gradual and significant improvement of vitD₃ status was demonstrated in the vitD₃ + PBA group compared with placebo (p < 0.0001) from week 0 to 16 (median 37.5 versus 115.5 nmol/L). No significant changes in HIV viral load, CD4⁺ or CD8⁺ T cell counts, BMI or MUAC could be detected. Clinical adverse events were similar in both groups. Daily vitD₃ + PBA for 16 weeks was well-tolerated and effectively improved vitD₃ status but did not reduce viral load, restore peripheral T cell counts or improve BMI or MUAC in HIV patients with slow progressive disease. Clinicaltrials.gov NCT01702974.
-
7.
25-Hydroxyvitamin D Measurement in Human Hair: Results from a Proof-of-Concept study.
Zgaga, L, Laird, E, Healy, M
Nutrients. 2019;11(2)
-
-
-
Free full text
Plain language summary
Vitamin-D deficiency is now considered to effect over 1 billion people world-wide and has known health implications including bone pathologies, immune dysfunction and metabolic diseases. It is thought that vitamin-D deficiency is increasing amongst the population due to our indoor lifestyles and increased use of sunscreens. The current method used to determine vitamin-D status is by measuring the concentration within blood circulation. Although considered accurate, this method can prove inconvenient and costly, especially for those requiring repeat or regular monitoring. A far simpler means of measurement is through hair analysis, although this method is in its infantry. The aim of this study was to investigate whether this method shows consistent markers in vitamin-D status which correlate to those of blood samples and whether hair analysis has potential for further research. The subjects in this study were the three authors who compared vitamin-D markers within their own hair to the markers within their blood serum concentrations. They found that although it is not possible to rely solely on hair analysis to measure vitamin-D status, it is possible to gain a picture of vitamin-D status historically, which can aid epidemiological research. Supplemental intake could also be monitored through longitudinal methods. Whilst the results were varied and inconclusive, the authors do suggest that there is scope for future research. Variations need to be accounted for, such as hair colour, age related differences plus methods of extracting the vitamin from the hair shaft.
Abstract
Vitamin D deficiency has been implicated in numerous human diseases leading to an increased interest in assessing vitamin D status. Consequentially, the number of requests for vitamin D measurement keeps dramatically increasing year-on-year. Currently, the recognised best marker of vitamin D status is the concentration of the 25-hydroxyvitamin D (25(OH)D₃) in the blood circulation. While providing an accurate estimate of vitamin D status at the point in time of sampling, it cannot account for the high variability of 25(OH)D₃ concentration. In this proof of concept study we set out to provide evidence that 25(OH)D₃ can be extracted from hair samples in a similar fashion to steroid hormones. Two of the authors (L.Z. and M.H.) provided hair samples harvested from the crown area of the scalp and the third author (E.L.) provided beard samples. These samples, cut into 1 cm lengths, were weighed, washed and dried. 25(OH)D was extracted using a previously published steroid hormones extraction procedure. Blood samples were taken from the subjects at the same time all tissue samples were analysed using liquid-chromatography mass spectrometry. Hair samples showed presence of quantifiable 25(OH)D₃ with concentrations ranging from 11.9⁻911 pg/mg. The beard sample had a concentration of 231 pg/mg. Serum levels of 25(OH)D₃ ranged from 72⁻78 nmol/L. The results presented here confirm the feasibility of measuring 25(OH)D₃ in hair samples. The findings warrant further validation and development and have the potential to yield valuable information relating to temporal trends in vitamin D physiology.
-
8.
Effects of Vitamin D Supplementation During Pregnancy on Birth Size: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.
Maugeri, A, Barchitta, M, Blanco, I, Agodi, A
Nutrients. 2019;11(2)
-
-
-
Free full text
Plain language summary
Vitamin D deficiency may affect mother and neonatal outcomes, increasing the risk of pregnancy complications, preterm birth, low birth weight (LBW), small for gestational age (SGA), and poor offspring health. This systematic review and meta-analysis evaluates the effects of oral vitamin D supplementation during pregnancy on foetal growth and incidence of LBW and SGA births. 13 randomised controlled trials (RCTs), published between 1980 and 2016, were included in the meta-analysis, including in total 2016 newborns (1184 from mothers in the intervention groups and 832 from controls). Dosages ranged from 200-4000 IU for daily intakes and 35000 IU to 600000 IU for single or intermittent administration. Whilst there was no evidence for publication bias (e.g. an over-reporting of positive outcomes), overall, the quality of the reviewed studies varied from very low (head circumference) to moderate (birth weight, birth length, LBW, and SGA). All studies evaluating the effect of vitamin D supplementation on blood 25-hydroxyvitamin D (OHD) levels showed that intervention significantly increased 25-OHD concentration in both mothers and infants. The meta-analysis showed that vitamin D supplementation significantly increased birth weight and length, independent of dosage and whether vitamin D was administered daily or in single/intermittent high dosages. Head circumference was increased in a non-dose dependent way with daily but not with single/intermittent vitamin D supplementation. Effects on all three parameters were seen when vitamin D was supplemented alone, but not in combination with other nutrients. Both, risk of LBW and SGA, were also significantly reduced with vitamin D supplementation.
Abstract
During pregnancy, vitamin D supplementation may be a feasible strategy to help prevent low birthweight (LBW) and small for gestational age (SGA) births. However, evidence from randomized controlled trials (RCTs) is inconclusive, probably due to heterogeneity in study design and type of intervention. A systematic literature search in the PubMed-Medline, EMBASE, and Cochrane Central Register of Controlled Trials databases was carried out to evaluate the effects of oral vitamin D supplementation during pregnancy on birthweight, birth length, head circumference, LBW, and SGA. The fixed-effects or random-effects models were used to calculate mean difference (MD), risk ratio (RR), and 95% Confidence Interval (CI). On a total of 13 RCTs, maternal vitamin D supplementation had a positive effect on birthweight (12 RCTs; MD = 103.17 g, 95% CI 62.29⁻144.04 g), length (6 RCTs; MD = 0.22 cm, 95% CI 0.11⁻0.33 cm), and head circumference (6 RCTs; MD:0.19 cm, 95% CI 0.13⁻0.24 cm). In line with these findings, we also demonstrated that maternal vitamin D supplementation reduced the risk of LBW (3 RCTs; RR = 0.40, 95% CI 0.22⁻0.74) and SGA (5 RCTS; RR = 0.69, 95% CI 0.51⁻0.92). The present systematic review and meta-analysis confirmed the well-established effect of maternal vitamin D supplementation on birth size. However, further research is required to better define risks and benefits associated with such interventions and the potential implications for public health.
-
9.
Vitamin D receptor gene FokI but not TaqI, ApaI, BsmI polymorphism is associated with Hashimoto's thyroiditis: a meta-analysis.
Wang, X, Cheng, W, Ma, Y, Zhu, J
Scientific reports. 2017;7:41540
-
-
-
Free full text
Plain language summary
Vitamin D is a vitamin that is involved in several immune processes within the body. It acts on immune cells through binding to vitamin D receptors (VDR) and modulating their activity. However genetic variations in VDRs is apparent amongst individuals, with the four most common being TaqI, ApaI, FokI and BsmI. The presence of any of these variations has been associated with the development of several different diseases. This systematic review and meta-analysis aimed to determine whether any of these variations in the VDR was associated with the development of Hashimoto’s thyroiditis (HT), a disease whereby the immune system does not recognise and attacks the body’s own tissues. The results showed that only the FokI variation was associated with the development of HT and only in individuals with Asian heritage. It was concluded that the FokI variation of the VDR is associated with an increased risk of HT in Asians but not Caucasians, however how this occurs is not fully understood. This study could be used by healthcare professionals to understand that genetic variations on the VDR may be indicative of risk of developing HT in individuals from Asian descent.
Abstract
Four VD receptor (VDR) gene polymorphisms (TaqI, ApaI, FokI and BsmI) have been reported to influence Hashimoto's thyroiditis (HT) risk. However, individual studies have produced inconsistent results. We conducted a comprehensive meta-analysis of eleven case-control studies to better understand roles of the four polymorphisms in HT development. The results showed only FokI polymorphism was significantly associated with the risk of HT (F vs f: OR = 1.44, 95% CI = 1.09-1.91, P = 0.010; FF vs Ff + ff: OR = 1.72, 95% CI = 1.09-2.70, P = 0.019). Subgroup analyses demonstrated the significant effect was only present in Asian population (F vs f: OR = 1.45, 95% CI = 1.07-1.95, P = 0.016; FF vs ff: OR = 1.64, 95% CI = 1.03-2.59, P = 0.036; FF + Ff vs ff: OR = 1.34, 95% CI = 1.00-1.80, P = 0.047; FF vs Ff + ff: OR = 1.64, 95% CI = 1.03-2.64, P = 0.039), but not in Caucasian. For TaqI, ApaI and BsmI polymorphisms, no significant association was found in any model comparison. Based on the current literature, it appears that only VDR FokI polymorphism is associated with HT risk in Asian population, but not in Caucasians; and the TaqI, ApaI and BsmI polymorphisms have not positive association neither in the overall population, nor when stratified by ethnicity. Further well-designed studies with larger sample sizes and different ethnic population are needed to clarify the present findings.