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The Journal of Steroid Biochemistry and... Oct 2014Vitamin D deficiency is a major public health problem worldwide in all age groups, even in those residing in countries with low latitude, where it was generally assumed... (Review)
Review
Vitamin D deficiency is a major public health problem worldwide in all age groups, even in those residing in countries with low latitude, where it was generally assumed that UV radiation was adequate enough to prevent this deficiency, and in industrialized countries, where vitamin D fortification has been implemented now for years. However, most countries are still lacking data, particularly population representative data, with very limited information in infants, children, adolescents and pregnant women. Since the number of recent publications is escalating, with a broadening of the geographic diversity, the objective of the present report was to conduct a more recent systematic review of global vitamin D status, with particular emphasis in at risk groups. A systematic review was conducted in PubMed/Medline in April-June 2013 to identify articles on vitamin D status worldwide published in the last 10 years in apparently healthy individuals. Only studies with vitamin D status prevalence were included. If available, the first source selected was population-based or representative samples studies. Clinical trials, case-control studies, case reports or series, reviews, validation studies, letters, editorials, or qualitative studies were excluded. A total of 103 articles were eligible and included in the present report. Maps were created for each age group, providing an updated overview of global vitamin D status. In areas with available data, the prevalence of low vitamin D status is a global problem in all age groups, in particular in girls and women from the Middle East. These maps also evidenced the regions with missing data for each specific population groups. There is striking lack of data in infants, children and adolescents worldwide, and in most countries of South America and Africa. In conclusion, vitamin D deficiency is a global public health problem in all age groups, particularly in those from the Middle East. This article is part of a Special Issue entitled '16th Vitamin D Workshop'.
Topics: Dietary Supplements; Global Health; Humans; Public Health; Vitamin D Deficiency
PubMed: 24239505
DOI: 10.1016/j.jsbmb.2013.11.003 -
Obesity Surgery Nov 2020Bariatric surgery may increase the risk of iron, vitamin B, folate and copper deficiencies, which can cause anaemia. This review aims to critique the evidence on the... (Review)
Review
Bariatric surgery may increase the risk of iron, vitamin B, folate and copper deficiencies, which can cause anaemia. This review aims to critique the evidence on the prevalence of these nutritional deficiencies and the impact on anaemia in the first 12 months after surgery. PRISMA and MOOSE frameworks, the NHMRC evidence hierarchy and The Academy of Nutrition and Dietetics bias tool were used to systematically critique current literature. Seventeen studies reported on deficiency prevalence with the majority being of low quality. Important confounders to serum micronutrient levels were not adequately considered. Results on the prevalence of nutritional anaemias were also lacking. Further investigation into the prevalence of iron, vitamin B, folate and copper deficiency and its impact on anaemia in bariatric surgery is needed.
Topics: Anemia; Bariatric Surgery; Copper; Folic Acid; Gastric Bypass; Humans; Iron; Obesity, Morbid; Vitamin B 12; Vitamin B 12 Deficiency; Vitamins
PubMed: 32785814
DOI: 10.1007/s11695-020-04872-y -
International Journal of Molecular... Jan 2022This review investigates the association between vitamin D and sleep disorders. Vitamin D is an essential nutrient known to play an important role in the growth and bone... (Review)
Review
This review investigates the association between vitamin D and sleep disorders. Vitamin D is an essential nutrient known to play an important role in the growth and bone health of the human body, but it also appears to play a role in sleep. The goal of our review is to examine the association between vitamin D and sleep disorders in children and adolescents. We summarize the evidence about the role and the mechanism of action of vitamin D in children and adolescents with sleep disorders such as insomnia, obstructive sleep apnea (OSA), restless legs syndrome (RLS), and other sleep disorders. Systematic electronic database searches were conducted using Pubmed and Cochrane Library. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline was followed. The studies that met the established inclusion criteria were analyzed and compared. Results suggest a strict relationship between vitamin D deficiency in children and sleep disorders. There is evidence that vitamin D is implicated in the different neurochemical mechanisms involved in sleep regulation and mainly in the serotonergic and dopaminergic pathways. This might be responsible for the association of vitamin D deficiency and restless sleep, sleep hyperhidrosis, OSA, and RLS.
Topics: Adolescent; Child; Dopamine; Female; Humans; Male; Serotonin; Sleep Wake Disorders; Vitamin D Deficiency
PubMed: 35163353
DOI: 10.3390/ijms23031430 -
Nutrients Dec 2020The association between vitamin D status and autism spectrum disorder (ASD) is well-investigated but remains to be elucidated. We quantitatively combined relevant... (Meta-Analysis)
Meta-Analysis Review
The association between vitamin D status and autism spectrum disorder (ASD) is well-investigated but remains to be elucidated. We quantitatively combined relevant studies to estimate whether vitamin D status was related to ASD in this work. PubMed, EMBASE, Web of Science, and the Cochrane Library were searched to include eligible studies. A random-effects model was applied to pool overall estimates of vitamin D concentration or odds ratio (OR) for ASD. In total, 34 publications involving 20,580 participants were identified in this present study. Meta-analysis of 24 case-control studies demonstrated that children and adolescents with ASD had significantly lower vitamin D concentration than that of the control group (mean difference (MD): -7.46 ng/mL, 95% confidence interval (CI): -10.26; -4.66 ng/mL, < 0.0001, I = 98%). Quantitative integration of 10 case-control studies reporting OR revealed that lower vitamin D was associated with higher risk of ASD (OR: 5.23, 95% CI: 3.13; 8.73, < 0.0001, I = 78.2%). Analysis of 15 case-control studies barring data from previous meta-analysis reached a similar result with that of the meta-analysis of 24 case-control studies (MD: -6.2, 95% CI: -9.62; -2.78, = 0.0004, I = 96.8%), which confirmed the association. Furthermore, meta-analysis of maternal and neonatal vitamin D showed a trend of decreased early-life vitamin D concentration in the ASD group (MD: -3.15, 95% CI: -6.57; 0.26, = 0.07, I = 99%). Meta-analysis of prospective studies suggested that children with reduced maternal or neonatal vitamin D had 54% higher likelihood of developing ASD (OR: 1.54, 95% CI: 1.12; 2.10, = 0.0071, I = 81.2%). These analyses indicated that vitamin D status was related to the risk of ASD. The detection and appropriate intervention of vitamin D deficiency in ASD patients and pregnant and lactating women have clinical and public significance.
Topics: Autism Spectrum Disorder; Databases, Factual; Female; Humans; Pregnancy; Pregnant Women; Vitamin D; Vitamin D Deficiency
PubMed: 33383952
DOI: 10.3390/nu13010086 -
Reviews in Endocrine & Metabolic... Dec 2023Bariatric surgery is associated with a postoperative reduction of 25(OH) vitamin D levels (25(OH)D) and with skeletal complications. Currently, guidelines for 25(OH)D... (Meta-Analysis)
Meta-Analysis Review
Bariatric surgery is associated with a postoperative reduction of 25(OH) vitamin D levels (25(OH)D) and with skeletal complications. Currently, guidelines for 25(OH)D assessment and vitamin D supplementation in bariatric patients, pre- and post-surgery, are still lacking. The aim of this work is to analyse systematically the published experience on 25(OH)D status and vitamin D supplementation, pre- and post-surgery, and to propose, on this basis, recommendations for management. Preoperatively, 18 studies including 2,869 patients were evaluated. Prevalence of vitamin D insufficiency as defined by 25(OH)D < 30 ng/mL (75 nmol/L) was 85%, whereas when defined by 25(OH)D < 20 ng/mL (50 nmol/L) was 57%. The median preoperative 25(OH)D level was 19.75 ng/mL. After surgery, 39 studies including 5,296 patients were analysed and among those undergoing either malabsorptive or restrictive procedures, a lower rate of vitamin D insufficiency and higher 25(OH)D levels postoperatively were observed in patients treated with high-dose oral vitamin D supplementation, defined as ≥ 2,000 IU/daily (mostly D3-formulation), compared with low-doses (< 2,000 IU/daily). Our recommendations based on this systematic review and meta-analysis should help clinical practice in the assessment and management of vitamin D status before and after bariatric surgery. Assessment of vitamin D should be performed pre- and postoperatively in all patients undergoing bariatric surgery. Regardless of the type of procedure, high-dose supplementation is recommended in patients after bariatric surgery.
Topics: Humans; Vitamin D; Vitamin D Deficiency; Dietary Supplements; Vitamins; Bariatric Surgery
PubMed: 37665480
DOI: 10.1007/s11154-023-09831-3 -
Clinical Nutrition (Edinburgh, Scotland) Jun 2020Maternal vitamin D deficiency has been associated with an increased risk for preeclampsia. Despite this, the current evidence regarding the efficacy of vitamin D... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Maternal vitamin D deficiency has been associated with an increased risk for preeclampsia. Despite this, the current evidence regarding the efficacy of vitamin D supplementation in preventing preeclampsia is controversial. To assess the impact of vitamin D supplementation on the risk of preeclampsia, we performed a systematic review of the literature and a meta-analysis of the available randomized clinical trials (RCTs).
METHODS
The primary outcome was preeclampsia. Subgroup analyses were carried out considering the timing of the supplementation, type of intervention and the study design. Meta-regression analysis, including the amount of vitamin D and maternal age, were planned to explore heterogeneity (PROSPERO database registration number: CRD42019119207).
RESULTS
Data were pooled from 27 RCTs comprising 59 arms, which included overall 4777 participants, of whom 2487 were in the vitamin D-treated arm and 2290 in the control arm. Vitamin D administration in pregnancy was associated with a reduced risk of preeclampsia (odd ratio [OR] 0.37, 95% confidence interval [CI]: 0.26, 0.52; I = 0%). If the vitamin D supplementation was started up to 20 weeks' gestation, the odds was a little lower (OR 0.35, 95% CI: 0.24, 0.50, p < 0.001). The effect was largely independent of the supplementation cessation (until delivery or not), type of intervention (vitamin D alone or in association with calcium), and study design. Increasing dose of vitamin D was associated with reduced incidence of preeclampsia (slope of log OR: -1.1, 95% CI: -1.73, -0.46; p < 0.001).
CONCLUSIONS
Results suggest that vitamin D supplementation may be useful in preventing preeclampsia. These data are especially useful for health-care providers who engage in the management of pregnant women at risk for preeclampsia. Our findings are a call for action to definitively address vitamin D supplementation as a possible intervention strategy in preventing preeclampsia in pregnancy.
Topics: Adolescent; Adult; Avitaminosis; Dietary Supplements; Female; Humans; Incidence; Middle Aged; Pre-Eclampsia; Pregnancy; Protective Factors; Randomized Controlled Trials as Topic; Risk Assessment; Risk Factors; Treatment Outcome; Vitamin D; Young Adult
PubMed: 31526611
DOI: 10.1016/j.clnu.2019.08.015 -
Diabetes & Metabolic Syndrome Oct 2022Metformin-treated type 2 diabetes mellitus (T2DM) patients are at higher risk of vitamin B deficiency and more severe neuropathy symptoms. There is still no guideline... (Review)
Review
The efficacy of vitamin B supplementation for treating vitamin B deficiency and peripheral neuropathy in metformin-treated type 2 diabetes mellitus patients: A systematic review.
BACKGROUND AND AIMS
Metformin-treated type 2 diabetes mellitus (T2DM) patients are at higher risk of vitamin B deficiency and more severe neuropathy symptoms. There is still no guideline suggesting vitamin B supplementation for this population. This study aimed to analyze the efficacy of vitamin B supplementation in this population.
METHOD
Studies reporting the efficacy of vitamin B supplementation in metformin-treated T2DM patients were systematically searched in PubMed, Cochrane, EBSCOHost, and Scopus following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. Additional relevant studies were searched manually through citations. Study quality and risk of bias were assessed using suitable tools.
RESULTS
Seven clinical trials with a total of 506 participants were included. Using the Cochrane's Risk of Bias 2 tools for clinical trials, 4 studies were assessed to have high risk of bias and 3 studies had low risk of bias. There were 5 studies that measured changes in serum vitamin B level, all of which reported a statistically significant increase after supplementation. Significant reductions in homocysteine after supplementation were found in 2 studies. Its effect on neuropathy symptoms was still unclear, with 2 studies reporting a significant improvement and 1 study reporting no significant effect.
CONCLUSIONS
The results of this systematic review support the implementation of vitamin B supplementation for metformin-treated T2DM to prevent or treat vitamin B deficiency and neuropathy. More high-quality clinical studies are required to generate quantitative analysis and to encourage supplementation in available guidelines.
Topics: Humans; Metformin; Diabetes Mellitus, Type 2; Vitamin B 12; Hypoglycemic Agents; Vitamin B 12 Deficiency; Peripheral Nervous System Diseases; Homocysteine; Dietary Supplements; Vitamins
PubMed: 36240684
DOI: 10.1016/j.dsx.2022.102634 -
Advances in Nutrition (Bethesda, Md.) May 2017Nutrition is considered to be a possible factor in the pathogenesis of the neurological disease multiple sclerosis (MS). Nutrition intervention studies suggest that diet... (Review)
Review
Nutrition is considered to be a possible factor in the pathogenesis of the neurological disease multiple sclerosis (MS). Nutrition intervention studies suggest that diet may be considered as a complementary treatment to control the progression of the disease; a systematic review of the literature on the influence of diet on MS was therefore conducted. The literature search was conducted by using Medlars Online International Literature (MEDLINE) via PubMed and Scopus. Forty-seven articles met the inclusion criteria. The reviewed articles assessed the relations between macro- and micronutrient intakes and MS incidence. The patients involved used alternative therapies (homeopathy), protocolized diets that included particular foods (herbal products such as grape seed extract, ginseng, blueberries, green tea, etc.), or dietary supplements such as vitamin D, carnitine, melatonin, or coenzyme Q10. Current studies suggest that high serum concentrations of vitamin D, a potent immunomodulator, may decrease the risk of MS and the risk of relapse and new lesions, while improving brain lesions and timed tandem walking. Experimental evidence suggests that serum vitamin D concentration is lower during MS relapses than in remission and is associated with a greater degree of disability [Expanded Disability Status Scale (EDSS) score >3]. The findings suggest that circulating vitamin D concentrations can be considered a biomarker of MS and supplemental vitamin D can be used therapeutically. Other studies point to a negative correlation between serum vitamin B-12 concentrations and EDSS score. Vitamin B-12 has fundamental roles in central nervous system function, especially in the methionine synthase-mediated conversion of homocysteine to methionine, which is essential for DNA and RNA synthesis. Therefore, vitamin B-12 deficiency may lead to an increase in the concentration of homocysteine. Further research is clearly necessary to determine whether treatment with vitamin B-12 supplements delays MS progression.
Topics: Diet; Dietary Supplements; Disease Progression; Humans; Multiple Sclerosis; Nutritional Status; Vitamin B 12; Vitamin B 12 Deficiency; Vitamin D; Vitamin D Deficiency; Vitamins
PubMed: 28507011
DOI: 10.3945/an.116.014191 -
Nutrition Reviews Jul 2023The popularity of plant-based diets, characterized by a partial or complete exclusion of animal products, has increased significantly over the last 10 years. The... (Meta-Analysis)
Meta-Analysis
CONTEXT
The popularity of plant-based diets, characterized by a partial or complete exclusion of animal products, has increased significantly over the last 10 years. The exclusion of animal products removes the most common sources of vitamin B12, which can lead to vitamin B12 deficiency and result in irreversible damage, such as growth stunting.
OBJECTIVE
This aim of this systematic review and meta-analysis was to qualitatively evaluate all studies on this subject and to quantify the potential difference in vitamin B12 levels in healthy children and adolescents aged 5 to 18 years.
DATA SOURCES
PubMed and Embase databases were searched for relevant studies investigating vitamin B12 levels in healthy children and adolescents aged 5 to 18 years on plant-based diets.
DATA EXTRACTION
Studies were assessed qualitatively with the AXIS tool and quantitatively with Stata 16.0 software.
DATA ANALYSIS
Overall, children and adolescents on plant-based diets had a significantly lower vitamin B12 level than omnivorous children and adolescents (-97 pmol/L; 95%CI, -187 to -7; I2 = 98.5%), a difference that remained statistically significant after adjusting for methodological confounders. After subgroup analyses, this effect was not statistically significant for children and adolescents on vegetarian diets but remained significant in children and adolescents on vegan or macrobiotic diets. Moreover, total vitamin B12 intake nullified the mean difference in vitamin B12 levels.
CONCLUSION
Despite high heterogeneity across studies, these results indicate that children and adolescents on plant-based diets, especially those on vegan and macrobiotic diets, may be at risk of developing vitamin B12 deficiency.
Topics: Child; Humans; Diet; Diet, Vegetarian; Nutritional Status; Vitamin B 12; Vitamin B 12 Deficiency
PubMed: 36413044
DOI: 10.1093/nutrit/nuac096 -
The Cochrane Database of Systematic... Dec 2020Vitamin D deficiency is common worldwide, contributing to nutritional rickets and osteomalacia which have a major impact on health, growth, and development of infants,... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Vitamin D deficiency is common worldwide, contributing to nutritional rickets and osteomalacia which have a major impact on health, growth, and development of infants, children and adolescents. Vitamin D levels are low in breast milk and exclusively breastfed infants are at risk of vitamin D insufficiency or deficiency.
OBJECTIVES
To determine the effect of vitamin D supplementation given to infants, or lactating mothers, on vitamin D deficiency, bone density and growth in healthy term breastfed infants.
SEARCH METHODS
We used the standard search strategy of Cochrane Neonatal to 29 May 2020 supplemented by searches of clinical trials databases, conference proceedings, and citations.
SELECTION CRITERIA
Randomised controlled trials (RCTs) and quasi-RCTs in breastfeeding mother-infant pairs comparing vitamin D supplementation given to infants or lactating mothers compared to placebo or no intervention, or sunlight, or that compare vitamin D supplementation of infants to supplementation of mothers.
DATA COLLECTION AND ANALYSIS
Two review authors assessed trial eligibility and risk of bias and independently extracted data. We used the GRADE approach to assess the certainty of evidence.
MAIN RESULTS
We included 19 studies with 2837 mother-infant pairs assessing vitamin D given to infants (nine studies), to lactating mothers (eight studies), and to infants versus lactating mothers (six studies). No studies compared vitamin D given to infants versus periods of infant sun exposure. Vitamin D supplementation given to infants: vitamin D at 400 IU/day may increase 25-OH vitamin D levels (MD 22.63 nmol/L, 95% CI 17.05 to 28.21; participants = 334; studies = 6; low-certainty) and may reduce the incidence of vitamin D insufficiency (25-OH vitamin D < 50 nmol/L) (RR 0.57, 95% CI 0.41 to 0.80; participants = 274; studies = 4; low-certainty). However, there was insufficient evidence to determine if vitamin D given to the infant reduces the risk of vitamin D deficiency (25-OH vitamin D < 30 nmol/L) up till six months of age (RR 0.41, 95% CI 0.16 to 1.05; participants = 122; studies = 2), affects bone mineral content (BMC), or the incidence of biochemical or radiological rickets (all very-low certainty). We are uncertain about adverse effects including hypercalcaemia. There were no studies of higher doses of infant vitamin D (> 400 IU/day) compared to placebo. Vitamin D supplementation given to lactating mothers: vitamin D supplementation given to lactating mothers may increase infant 25-OH vitamin D levels (MD 24.60 nmol/L, 95% CI 21.59 to 27.60; participants = 597; studies = 7; low-certainty), may reduce the incidences of vitamin D insufficiency (RR 0.47, 95% CI 0.39 to 0.57; participants = 512; studies = 5; low-certainty), vitamin D deficiency (RR 0.15, 95% CI 0.09 to 0.24; participants = 512; studies = 5; low-certainty) and biochemical rickets (RR 0.06, 95% CI 0.01 to 0.44; participants = 229; studies = 2; low-certainty). The two studies that reported biochemical rickets used maternal dosages of oral D3 60,000 IU/day for 10 days and oral D3 60,000 IU postpartum and at 6, 10, and 14 weeks. However, infant BMC was not reported and there was insufficient evidence to determine if maternal supplementation has an effect on radiological rickets (RR 0.76, 95% CI 0.18 to 3.31; participants = 536; studies = 3; very low-certainty). All studies of maternal supplementation enrolled populations at high risk of vitamin D deficiency. We are uncertain of the effects of maternal supplementation on infant growth and adverse effects including hypercalcaemia. Vitamin D supplementation given to infants compared with supplementation given to lactating mothers: infant vitamin D supplementation compared to lactating mother supplementation may increase infant 25-OH vitamin D levels (MD 14.35 nmol/L, 95% CI 9.64 to 19.06; participants = 269; studies = 4; low-certainty). Infant vitamin D supplementation may reduce the incidence of vitamin D insufficiency (RR 0.61, 95% CI 0.40 to 0.94; participants = 334; studies = 4) and may reduce vitamin D deficiency (RR 0.35, 95% CI 0.17 to 0.72; participants = 334; studies = 4) but the evidence is very uncertain. Infant BMC and radiological rickets were not reported and there was insufficient evidence to determine if maternal supplementation has an effect on infant biochemical rickets. All studies enrolled patient populations at high risk of vitamin D deficiency. Studies compared an infant dose of vitamin D 400 IU/day with varying maternal vitamin D doses from 400 IU/day to > 4000 IU/day. We are uncertain about adverse effects including hypercalcaemia.
AUTHORS' CONCLUSIONS
For breastfed infants, vitamin D supplementation 400 IU/day for up to six months increases 25-OH vitamin D levels and reduces vitamin D insufficiency, but there was insufficient evidence to assess its effect on vitamin D deficiency and bone health. For higher-risk infants who are breastfeeding, maternal vitamin D supplementation reduces vitamin D insufficiency and vitamin D deficiency, but there was insufficient evidence to determine an effect on bone health. In populations at higher risk of vitamin D deficiency, vitamin D supplementation of infants led to greater increases in infant 25-OH vitamin D levels, reductions in vitamin D insufficiency and vitamin D deficiency compared to supplementation of lactating mothers. However, the evidence is very uncertain for markers of bone health. Maternal higher dose supplementation (≥ 4000 IU/day) produced similar infant 25-OH vitamin D levels as infant supplementation of 400 IU/day. The certainty of evidence was graded as low to very low for all outcomes.
Topics: 25-Hydroxyvitamin D 2; Bone Density; Bone and Bones; Breast Feeding; Female; Humans; Hypercalcemia; Infant; Lactation; Mothers; Randomized Controlled Trials as Topic; Rickets; Term Birth; Vitamin D; Vitamin D Deficiency; Vitamins
PubMed: 33305822
DOI: 10.1002/14651858.CD013046.pub2