B vitamins

Authors:

Marcel Hrubša

Findings:

This review summarizes current knowledge on essential vitamins B1, B2, B3, and B5. These vitamins are generally obtained from diet (B3 also via tryptophan), are water-soluble (affecting food processing loss, cellular uptake, and safety via renal elimination), and their therapeutic use is mainly for hypovitaminoses, though their safety allows for other investigations. Nicotinic acid (B3) is noted as a hypolipidemic agent in gram doses. The article also details detection methods, food sources, processing/storage effects, and physiological functions of these vitamins.

Dosage:

The review details various dosages: Thiamine (B1) RDAs (e.g., 1.1 mg/day for women, 1.2 mg/day for men), therapeutic doses for deficiency (e.g., 50–100 mg IV daily for adults with beriberi, then 10 mg/day IM, followed by 3–5 mg oral daily; 25–30 mg IV initial dose for infantile beriberi; 50–100 mg SC/IV twice daily for Wernicke-Korsakoff syndrome), and 100–300 mg IV daily for critically ill patients. Nicotinic acid (B3) in gram doses (e.g., 1000–6000 mg/day) for dyslipidemia, and 10–300 mg/day (up to 1000 mg/day) for pellagra. Pantethine (B5 derivative) at 600–900 mg/day for dyslipidemia (e.g., 300 mg three times daily); pantothenic acid at 2.2 g/day for acne. Dexpanthenol (B5) topically at 2–5%.

Study Quality Assessment:

The text identifies the document as a review article: "This review summarizes the current knowledge on essential vitamins B1, B2, B3, and B5." It is published in "Nutrients . 2022 Jan 22;14(3):484", an open-access journal, under a Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). The article includes a DOI (10.3390/nu14030484), PMCID (PMC8839250), and PMID (35276844). It mentions an editor ("Editor: Ebba Nexø"), funding sources ("Erasmus+ Programme of the European Union, Key Action 2: Strategic Partnerships, Project no. 2020-1-CZ01-KA203-078218. MH thanks to the Charles University (SVV 260 549). LKK and LJ give thanks to MH-CZ-DRO (UHHK, 00179906)"), and a declaration of no conflict of interest by the authors. The review covers methods for vitamin detection, food sources, processing effects, and physiological functions.

All Effects:

Authors:

KRISTJANA DHULI, ZAKIRA NAUREEN

Findings:

This review highlights that diet quality, particularly the Mediterranean diet, is strongly associated with brain health and can influence neurological diseases and mental health. Adopting a healthy diet rich in bioactive compounds with antioxidant, anti-inflammatory, neuroprotective, and other beneficial activities can aid in the prevention and management of neurological diseases (like Alzheimer's, Parkinson's, Huntington's, MS, ALS) and brain aging. The review discusses various dietary components, natural compounds (e.g., polyphenols, omega-3 fatty acids, B vitamins, N-acetylcysteine, phospholipids, GABA, melatonin, S-adenosyl methionine, tryptophan, magnesium), and medicinal plants (e.g., Bacopa monnieri, Withania somnifera) that have shown promise in mitigating neurodegeneration, though their effects are often dose-dependent and require further large-scale clinical trials.

Participants:

This review article discusses numerous studies involving diverse human participants and animal models. Human participants include: individuals with normal cognitive function (e.g., N=70, age 30-60 years; N=52; N=44 healthy volunteers; N=8 stressed volunteers; N=260 healthy subjects 60-94 years), individuals with mild cognitive impairment (N=482, age 76.7-77.5 years), patients with dementia (N=1865, mean age 73 years), Alzheimer's disease (AD) risk participants (N=38), AD patients (N=25), elderly persons with impaired memory or cognitive impairment (N=130; N=494; N=101 geriatric patients), Parkinson's disease (PD) patients (N=1731 PD-free individuals age 65+; N=13 PD patients with depression; N=249 PD patients), Huntington’s disease patients (N=211), amyotrophic lateral sclerosis (ALS) patients (N=302; N=31 sporadic), multiple sclerosis (MS) patients (N=396), patients with bipolar disorder (N=30; 23 women), children with ADHD, women with PMS (N=40, age 18-45 years), menopausal patients (N=20), young adult prisoners (N=231), SAD patients (N=11), patients with impaired intellectual function (N=16), medical students (N=68), patients without dementia (N=5386; N=1081 Japanese), stroke patients (N=2589), and adult smokers (N=120). Animal models mentioned include: Male Wistar rats, TgCRND8 mice (AD model), SOD1 (G93A) mice (ALS model), BV-2 murine microglial cells, depression animal model, ICR mice, and a stress-induced mouse model.

Dosage:

As a review, the text cites various dosages from different studies for numerous supplements. Examples include: Melatonin (0.25-1.25 mg/kg i.v.; 3 mg/day for migraine; 50-300 mg/day oral for MS; 60 mg/day oral or 300 mg/day rectal for ALS), Phosphatidylserine (PS) (100 mg/day PS-DHA; 300 mg/day soy-derived PS; 400 mg PS + 400 mg PA per day for PMS), Omega-3 fatty acids (e.g., 2.5 g/day n-3, containing 2085 mg EPA and 348 mg DHA for anxiety in students), S-adenosyl methionine (SAMe) (800 or 1600 mg/day for smoking abstinence; 800-3600 mg/day for depression in PD; 800 mg/day for depression), Magnesium (a bolus dose of 16 mmol MgSO4 infused over 15 min, then 65 mmol MgSO4 over 24h for cerebral ischemia). The text notes that effects are dose-dependent.

Study Quality Assessment:

This is a review article titled 'Dietary supplements in neurological diseases and brain aging' published in 'J Prev Med Hyg . 2022 Oct 17;63(2 Suppl 3):E174–E188.' (PMCID: PMC9710403, PMID: 36479494). The review cites a wide range of study types, including: clinical studies, follow-up studies, cohort studies (including population-based), longitudinal studies, cross-sectional studies (including baseline analysis), prospective studies, surveys, in vitro studies, animal studies, randomized controlled trials (some specified as double-blind, placebo-controlled, balanced crossover), open-label clinical trials, pilot clinical trials, epidemiological cohort studies, comprehensive geriatric assessments, and case-control studies (e.g., IMAGES trial). The research was funded by 'the Provincia Autonoma di Bolzano in the framework of LP 15/2020 (dgp 3174/2021)'. The authors 'declare no conflict of interest'.

All Effects:

Findings:

The meta-analysis found a significant benefit of multi-nutrient formulas containing both n-3 PUFA and B vitamins (often alongside other nutrients) versus placebo on global cognition assessed using composite scores from a neuropsychological test battery (G = 0.23, P = 0.002), global cognition using single measures of cognition (G = 0.28, P = 0.004), and episodic memory (G = 0.32, P = 0.001) in older adults. No significant effect was found for executive function in the primary meta-analysis. Sub-group analyses suggested benefits for episodic memory and executive function in healthy older adults, and for global cognition and episodic memory in those with MCI.

Participants:

Systematic review and meta-analysis of 14 papers (total N=4913 participants). Participants were older adults (mean age typically 60–70 years, with one study mean age 87 years; follow-up duration 24 weeks to 4 years). Participant health status at baseline varied across studies: cognitively healthy, subjective memory complaint, mild cognitive impairment (MCI), prodromal Alzheimer’s Disease, diagnosed Alzheimer’s Disease, or cognitively healthy with a prior cardiovascular event.

Dosage:

Dosages varied across the 14 included studies, which provided combinations of n-3 PUFA and B vitamins, often as part of multi-nutrient formulas with additional ingredients. Examples of daily dosages from specific trials include: Fortasyn Connect blend (e.g., 300 mg EPA, 1200 mg DHA, 400 μg folic acid, 3 μg vitamin B12, 1 mg vitamin B6); another formula (e.g., 1 g DHA, 160 mg EPA, 1 mg folic acid, 20 μg vitamin B12); a combination of 800 μg folic acid and 800 mg DHA. The review noted that all nutrient formulas included in the meta-analyses had a DHA dosage greater than 580 mg per day.

Study Quality Assessment:

Systematic review and meta-analysis of randomised controlled trials (RCTs). Included trials were placebo-controlled. Databases searched: The Cochrane Library, EMBASE, CINAHL, Scopus, MEDLINE. A total of 14 papers were included (n=4913 participants; follow-up 24 weeks to 4 years). Risk of bias in individual studies was assessed using the Revised Cochrane risk-of-bias tool for randomised trials (RoB 2). Meta-analysis used random-effects models and Hedges G statistic. Statistical heterogeneity was assessed (χ2 test and I2 statistic). Sub-group analyses were performed based on baseline cognitive health status. Limitations mentioned: heterogeneity in cognitive testing methods and domains; some included studies had concerns of bias (e.g., unclear score calculation, missing data); ten of the included studies received funding or support from supplement manufacturers; screening and data extraction processes were not fully independent and in duplicate.

All Effects:

Authors:

Anne-Laure Tardy, Etienne Pouteau

Findings:

This narrative review concludes there is a strong biological and physiological rationale for the involvement of selected vitamins (B vitamins, C) and minerals (iron, magnesium, zinc) in cellular energy production, which translates to effects on physical and mental fatigue, and cognitive and psychological functions. Subclinical or marginal deficiencies can negatively impact these areas, and supplementation is likely beneficial, though caution regarding dosage is needed. Adequate intake contributes to normal cognitive function, enhanced well-being, decreased fatigue, and positive mood.

Participants:

The review focuses on human data, primarily from adult and adolescent populations, including healthy individuals and those with inadequate nutrient intake or status. Selected data from younger and older populations are also included where relevant.

Dosage:

The review cites various dosages from numerous studies for B vitamins, vitamin C, iron, magnesium, and zinc. Examples include: Thiamine (B1) 50-300mg/day; Riboflavin (B2) 2-100mg; Folic acid (B9) 400µg-1mg/day (one study cited 15g/day for 60 days); Vitamin C 500mg-6g/day (one study 10g IV); Iron 42-80mg/day or 1g infusion; Magnesium 250-800mg/day or 8-10mg/kg/day; Zinc 15-30mg/day. The review emphasizes caution against overdosing and suggests staying within RDA magnitudes for safety.

Study Quality Assessment:

Narrative review. Funding acknowledged from Sanofi, with several authors being employees of Sanofi, indicating potential funding source bias. The review states priority is given to human data and aims to examine scientific evidence, while noting that some rationale for claims is based on biochemical grounds or frank deficiencies rather than robust empirical physiological data for subclinical states.

All Effects:

Findings:

This systematic review and meta-analysis of 17 studies estimated the global prevalence of anxiety symptoms among older adults to be 28% (95% CI: 21%–35%). Subgroup analyses indicated that the continent of residence and the assessment tools (Geriatric Anxiety Inventory - GAI, or Geriatric Anxiety Scale - GAS) significantly affect the overall prevalence. The most reported associated factors for anxiety encompassed sociodemographic (e.g., female gender), health-related (e.g., physical comorbidities), and psychosocial domains (e.g., low social support, social isolation).

Participants:

Older adults. The review focused on older adults as defined by the included studies. Examples of participant populations from the 17 reviewed studies (sample sizes ranging from 58 to 897) include patients of geriatric psychiatry departments, centenarians, community-dwelling older adults, primary care patients, and residents of old age homes.

Study Quality Assessment:

Systematic review and meta-analysis of 17 epidemiological or cross-sectional studies. Adhered to PRISMA guidelines; protocol registered in PROSPERO (CRD42023425147). Comprehensive search of Medline (via PubMed), Embase, Web of Science, and Scopus databases conducted up to February 27, 2023. Quality of included studies assessed using the Joanna Briggs Institute (JBI) Critical Appraisal Tool for Prevalence Studies. Data synthesis used a random effects model for meta-analysis. Significant heterogeneity was observed (I2=96%). Publication bias was assessed using funnel plot visualization and the Egger test (p=0.19, no indication of publication bias). Limitations acknowledged include: included studies were mostly cross-sectional, potential for publication bias and language restrictions, sample representativeness (many participants from older adult care facilities or hospital patients), and the overall sample size of approximately 4200 from 17 studies considered insufficient for the global older population.

All Effects: