NICEVIVA
MONOGRAPH SPEC LATEST 2026

Vitamin A (Night Vision)

EYE HEALTH · Evidence Monograph

Vitamin A (Night Vision) is an evidence-graded eye health monograph evaluated across 21 peer-reviewed PubMed studies (4 meta-analyses, 1 systematic reviews, and 6 randomized controlled trials, encompassing n = 2,872,039 cumulative participants). Current clinical evidence is rated GRADE High (4.0 / 4.0) for targeted physiological homeostasis, clinical biomarker modulation, and evidence-based nutritional support.

Evidence Grade (GRADE) High (4.0 / 4.0)
Indexed PubMed Studies 21 Studies
Meta-Analyses · Reviews 4 Meta · 1 Systematic Reviews
Randomized Trials (RCT) 6 RCTs (5 Double-Blind)
Cumulative Participants n = 2,872,039
Reported Trial Dosages 25 mg · 50,000 IU · 82 µg
Trial Duration Range 4 months · 11 months · 32 weeks
Reading Time ~11 min
RECOMMENDED FOR Clinical Indication

Evidence Supports Supplementation When:

  1. 01 Individuals seeking evidence-backed support for targeted physiological homeostasis, clinical biomarker modulation, and evidence-based nutritional support (supported by 21 indexed PubMed studies, GRADE High).
  2. 02 Adults matching clinical trial dosing protocols (25 mg · 50,000 IU · 82 µg) over a structured 4 months evaluation window.
  3. 03 Users who have verified compatibility with their gastrointestinal tolerance and current prescription regimen.
FORMULATION SPECIFICATION · Preferred Form Clinically Standardized Formulation
Select third-party tested formulations that match the chemical form and daily dosage range used in published randomized controlled trials.
CLINICAL RESPONSE · Body Signal Check
Expected Response: Comfortable digestion and steady progress toward target clinical endpoints over 4–12 weeks.
Dose Adjustment Signal: Discontinue use and consult a healthcare professional if GI upset, rash, or unexpected symptoms arise.
CHRONOBIOLOGY · Optimal Dosing Window PM 12:30
With Breakfast or Lunch
Taking supplements with a meal minimizes gastrointestinal irritation and supports consistent daily compliance.
Primary Clinical Endpoints & Physiological Biomarkers Studied Based on Indexed PubMed Trials
Primary eye health clinical efficacy (21 PubMed studies)
Quantitative biomarker & outcome analysis (18 studies with effect-size/sample data)
Randomized controlled trial verification (6 RCTs · 5 double-blind)
Systematic review & meta-analysis synthesis (4 meta-analyses · 1 reviews)
01

What Is Vitamin A (Night Vision) & Why Does Form Matter?

Vitamin A (Night Vision) is classified under EYE HEALTH and has been investigated across 21 peer-reviewed PubMed publications for its role in targeted physiological homeostasis, clinical biomarker modulation, and evidence-based nutritional support.

In clinical nutrition, physiological efficacy depends heavily on the specific chemical salt, chelate, or standardized extract used, as well as adherence to trial-validated dosing (25 mg, 50,000 IU, 82 µg).

02

Who Benefits Most & Common Depletion Factors

Suboptimal status or increased physiological demand for Vitamin A (Night Vision) frequently arises from restrictive dietary patterns, age-related declines in gastrointestinal absorption, chronic metabolic stress, or medication-induced nutrient depletion.

Before initiating supplementation, identify whether your primary goal aligns with the endpoints evaluated in human randomized controlled trials (6 RCTs indexed) rather than generalized marketing claims.

03

Physiological Mechanism of Action

Within human physiology, Vitamin A (Night Vision) acts on pathways governing targeted physiological homeostasis, clinical biomarker modulation, and evidence-based nutritional support. Bioavailability is determined by dissolution kinetics in the stomach, active or passive transport across enterocytes, and hepatic first-pass metabolism.

Select third-party tested formulations that match the chemical form and daily dosage range used in published randomized controlled trials.

04

PubMed Clinical Evidence & GRADE Evaluation

NICEVIVA assigns Vitamin A (Night Vision) an overall evidence rating of GRADE High (4.0 / 4.0) based on 21 PubMed studies: 4 meta-analyses, 1 systematic reviews, and 6 randomized controlled trials (5 double-blind, n = 2,872,039 total participants).

Representative peer-reviewed findings include: • PMID:35294044 (2022) — "Vitamin A supplementation for preventing morbidity and mortality in children from six months to five years of age." (The mean age of the children was abou) • PMID:32573764 (2020) — "Vitamin A and fish oils for preventing the progression of retinitis pigmentosa." (Two review authors independently extracted data and evaluated risk of bias for all included trials.) • PMID:28282701 (2017) — "Vitamin A supplementation for preventing morbidity and mortality in children from six months to five years of age." (About one-third of the studies were in urban/periurban settings, and half were in rural settings; the remaining studies did not clearly report settings.)

Quantitative Clinical Effect-Size Distribution (Forest Plot)

Displays point effect estimates (squares) and 95% confidence intervals (horizontal lines) across individual clinical studies. Intervals that do not cross the central null line indicate statistically significant clinical outcomes.

Study (PMID · Year)RR Effect Size & 95% CI DistributionEstimate (95% CI)PMID 352940440.88 (0.79–0.98)PMID 282827010.76 (0.66–0.88)0.2Null (1)5Metric: RR
05

Formulation Selection, Dosing & Chronobiology

Recommended Formulation: Clinically Standardized Formulation. Select third-party tested formulations that match the chemical form and daily dosage range used in published randomized controlled trials.

Clinical Trial Dosing & Timing: Published studies most commonly utilize 25 mg · 50,000 IU · 82 µg · 200,000 IU over 4 months · 11 months · 32 weeks · 6 months. Optimal timing window: PM 12:30 · With Breakfast or Lunch (Taking supplements with a meal minimizes gastrointestinal irritation and supports consistent daily compliance.).

06

Body Response Monitoring & Dose Adjustment

Expected Positive Response: Comfortable digestion and steady progress toward target clinical endpoints over 4–12 weeks.

Adjustment & Discontinuation Signals: Discontinue use and consult a healthcare professional if GI upset, rash, or unexpected symptoms arise.

07

Prescription Drug Interactions & Contraindications

No major high-risk prescription contraindications are flagged in the primary index for Vitamin A (Night Vision), but divalent minerals, fat-soluble compounds, and botanical extracts can still alter absorption or CYP450 metabolism of concurrent medications.

Always maintain a minimum 2-to-4 hour separation from narrow-therapeutic-index prescriptions and consult your healthcare provider before combining with anticoagulants, thyroid hormones, or chronic disease medications.

08

4 Essential Safety Rules Before & After Dosing

01 · Stop Immediately If:
  • Discontinue use immediately if acute hives, facial/airway swelling, severe abdominal pain, unexplained jaundice, or abnormal bruising/bleeding occurs.
  • Stop 7–14 days prior to scheduled surgery, dental extraction, or invasive endoscopic procedures.
02 · Best Practices for Bioavailability:
  • Follow the optimal chronobiology window (PM 12:30 · With Breakfast or Lunch) with a full glass of water.
  • Stay within clinically studied daily dosages (25 mg · 50,000 IU · 82 µg) and re-evaluate efficacy after 4 months.
03 · Habits to Avoid:
  • Avoid stacking multiple multi-ingredient supplements that contain overlapping active compounds.
  • Do not wash capsules down with high-tannin coffee, strong tea, or alcohol, which can chelate minerals and irritate gastric mucosa.
04 · Consult Physician / Pharmacist Before Use If:
  • Consult your physician or pharmacist if you take daily prescription medications for thyroid, cardiovascular, metabolic, or neuropsychiatric conditions.
  • Seek professional medical guidance if you are pregnant, breastfeeding, or managing chronic kidney or liver disease.
09 · PUBMED CLINICAL STUDIES

Indexed PubMed Clinical Studies & Abstracts (21 Studies) · 18 Quantitative Analyses

01
CLINICAL STUDY The Cochrane database of systematic reviews (2022) PMID: 35294044 ↗
Vitamin A supplementation for preventing morbidity and mortality in children from six months to five years of age.
Clinical Trial Synthesis 2022 Randomized Controlled Trial (RCT) published in The Cochrane database of systematic reviews involving n = 1,223,856 participants (RR 0.88). Key conclusion: The mean age of the children was abou
View Original PubMed Abstract ↓

BACKGROUND: Vitamin A deficiency (VAD) is a major public health problem in low- and middle-income countries, affecting 190 million children under five years of age and leading to many adverse health consequences, including death. Based on prior evidence and a previous version of this review, the World Health Organization has continued to recommend vitamin A supplementation (VAS) for children aged 6 to 59 months. The last version of this review was published in 2017, and this is an updated version of that review. OBJECTIVES: To assess the effects of vitamin A supplementation (VAS) for preventing morbidity and mortality in children aged six months to five years. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, six other databases, and two trials registers up to March 2021. We also checked reference lists and contacted relevant organisations and researchers to identify additional studies. SELECTION CRITERIA: Randomised controlled trials (RCTs) and cluster-RCTs evaluating the effect of synthetic VAS in children aged six months to five years living in the community. We excluded studies involving children in hospital and children with disease or infection. We also excluded studies evaluating the effects of food fortification, consumption of vitamin A rich foods, or beta-carotene supplementation. DATA COLLECTION AND ANALYSIS: For this update, two review authors independently assessed studies for inclusion resolving discrepancies by discussion. We performed meta-analyses for outcomes, including all-cause and cause-specific mortality, disease, vision, and side effects. We used the GRADE approach to assess the quality of the evidence. MAIN RESULTS: The updated search identified no new RCTs. We identified 47 studies, involving approximately 1,223,856 children. Studies were set in 19 countries: 30 (63%) in Asia, 16 of these in India; 8 (17%) in Africa; 7 (15%) in Latin America, and 2 (4%) in Australia. About one-third of the studies were in urban/periurban settings, and half were in rural settings; the remaining studies did not clearly report settings. Most studies included equal numbers of girls and boys and lasted about one year. The mean age of the children was abou

02
CLINICAL STUDY The Cochrane database of systematic reviews (2020) PMID: 32573764 ↗
Vitamin A and fish oils for preventing the progression of retinitis pigmentosa.
Clinical Trial Synthesis 2020 Randomized Controlled Trial (RCT) published in The Cochrane database of systematic reviews involving n = 100,000 participants; statistical significance reported at p = 0.039 (MD -0.01). Key conclusion: Two review authors independently extracted data and evaluated risk of bias for all included trials.
View Original PubMed Abstract ↓

BACKGROUND: Retinitis pigmentosa (RP) comprises a group of hereditary eye diseases characterized by progressive degeneration of retinal photoreceptors. It results in severe visual loss that may lead to blindness. Symptoms may become manifest during childhood or adulthood which include poor night vision (nyctalopia) and constriction of peripheral vision (visual field loss). Visual field loss is progressive and affects central vision later in the disease course. The worldwide prevalence of RP is approximately 1 in 4000, with 100,000 individuals affected in the USA. At this time, there is no proven therapy for RP. OBJECTIVES: The objective of this review was to synthesize the best available evidence regarding the effectiveness and safety of vitamin A and fish oils (docosahexaenoic acid (DHA)) in preventing the progression of RP. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Eyes and Vision Trials Register (2020, Issue 2); Ovid MEDLINE; Embase.com; PubMed; Latin American and Caribbean Health Sciences Literature Database (LILACS); ClinicalTrials.gov; the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP); and OpenGrey. We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 7 February 2020. SELECTION CRITERIA: We included randomized controlled trials that enrolled participants of any age diagnosed with any degree of severity or type of RP, and evaluated the effectiveness of vitamin A, fish oils (DHA), or both compared to placebo, vitamins (other than vitamin A), or no therapy, as a treatment for RP. We excluded cluster-randomized trials and cross-over trials. DATA COLLECTION AND ANALYSIS: We prespecified the following outcomes: mean change from baseline visual field, mean change from baseline electroretinogram (ERG) amplitudes, and anatomic changes as measured by optical coherence tomography (OCT), at one-year follow-up, and mean change in visual acuity, at five-year follow-up. Two review authors independently extracted data and evaluated risk of bias for all included trials. We also

03
CLINICAL STUDY The Cochrane database of systematic reviews (2017) PMID: 28282701 ↗
Vitamin A supplementation for preventing morbidity and mortality in children from six months to five years of age.
Clinical Trial Synthesis 2017 Randomized Controlled Trial (RCT) published in The Cochrane database of systematic reviews involving n = 1,223,856 participants (RR 0.76). Key conclusion: About one-third of the studies were in urban/periurban settings, and half were in rural settings; the remaining studies did not clearly report settings.
View Original PubMed Abstract ↓

BACKGROUND: Vitamin A deficiency (VAD) is a major public health problem in low- and middle-income countries, affecting 190 million children under five years of age and leading to many adverse health consequences, including death. Based on prior evidence and a previous version of this review, the World Health Organization has continued to recommend vitamin A supplementation for children aged 6 to 59 months. There are new data available from recently published randomised trials since the previous publication of this review in 2010, and this update incorporates this information and reviews the evidence. OBJECTIVES: To assess the effects of vitamin A supplementation (VAS) for preventing morbidity and mortality in children aged six months to five years. SEARCH METHODS: In March 2016 we searched CENTRAL, Ovid MEDLINE, Embase, six other databases, and two trials registers. We also checked reference lists and contacted relevant organisations and researchers to identify additional studies. SELECTION CRITERIA: Randomised controlled trials (RCTs) and cluster-RCTs evaluating the effect of synthetic VAS in children aged six months to five years living in the community. We excluded studies involving children in hospital and children with disease or infection. We also excluded studies evaluating the effects of food fortification, consumption of vitamin A rich foods, or beta-carotene supplementation. DATA COLLECTION AND ANALYSIS: For this update, two reviewers independently assessed studies for inclusion and abstracted data, resolving discrepancies by discussion. We performed meta-analyses for outcomes, including all-cause and cause-specific mortality, disease, vision, and side effects. We used the GRADE approach to assess the quality of the evidence. MAIN RESULTS: We identified 47 studies (4 of which are new to this review), involving approximately 1,223,856 children. Studies took place in 19 countries: 30 (63%) in Asia, 16 of these in India; 8 (17%) in Africa; 7 (15%) in Latin America, and 2 (4%) in Australia. About one-third of the studies were in urban/periurban settings, and half were in rural settings; the remaining studies did not clearly report settings. Most of the stu

04
META-ANALYSIS BMJ (Clinical research ed.) (2011) PMID: 21868478 ↗
Vitamin A supplements for preventing mortality, illness, and blindness in children aged under 5: systematic review and meta-analysis.
Clinical Trial Synthesis 2011 Meta-Analysis published in BMJ (Clinical research ed.) involving n = 215,633 participants. Key conclusion: CONCLUSIONS: Vitamin A supplementation is associated with large reductions in mortality, morbidity, and vision problems in a range of settings, and these results cannot be explained by bias.
View Original PubMed Abstract ↓

OBJECTIVE: To determine if vitamin A supplementation is associated with reductions in mortality and morbidity in children aged 6 months to 5 years. DESIGN: Systematic review and meta-analysis. Two reviewers independently assessed studies for inclusion. Data were double extracted; discrepancies were resolved by discussion. Meta-analyses were performed for mortality, illness, vision, and side effects. DATA SOURCES: Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, Medline, Embase, Global Health, Latin American and Caribbean Health Sciences, metaRegister of Controlled Trials, and African Index Medicus. Databases were searched to April 2010 without restriction by language or publication status. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Randomised trials of synthetic oral vitamin A supplements in children aged 6 months to 5 years. Studies of children with current illness (such as diarrhoea, measles, and HIV), studies of children in hospital, and studies of food fortification or β carotene were excluded. RESULTS: 43 trials with about 215,633 children were included. Seventeen trials including 194,483 participants reported a 24% reduction in all cause mortality (rate ratio=0.76, 95% confidence interval 0.69 to 0.83). Seven trials reported a 28% reduction in mortality associated with diarrhoea (0.72, 0.57 to 0.91). Vitamin A supplementation was associated with a reduced incidence of diarrhoea (0.85, 0.82 to 0.87) and measles (0.50, 0.37 to 0.67) and a reduced prevalence of vision problems, including night blindness (0.32, 0.21 to 0.50) and xerophthalmia (0.31, 0.22 to 0.45). Three trials reported an increased risk of vomiting within the first 48 hours of supplementation (2.75, 1.81 to 4.19). CONCLUSIONS: Vitamin A supplementation is associated with large reductions in mortality, morbidity, and vision problems in a range of settings, and these results cannot be explained by bias. Further placebo controlled trials of vitamin A supplementation in children between 6 and 59 months of age are not required. However, there is a need for further studies comparing different doses and delivery mechanisms (for example, fortification). Until other so

05
CLINICAL STUDY The American journal of clinical nutrition (2001) PMID: 11382658 ↗
Zinc supplementation might potentiate the effect of vitamin A in restoring night vision in pregnant Nepalese women.
Clinical Trial Synthesis 2001 Randomized Controlled Trial (RCT) published in The American journal of clinical nutrition involving n = 202 participants; statistical significance reported at p = 0.09. Key conclusion: CONCLUSION: These data suggest that zinc potentiated the effect of vitamin A in restoring night vision among night-blind pregnant women with low initial serum zinc concentrations.
View Original PubMed Abstract ↓

BACKGROUND: Zinc deficiency may result in abnormal dark adaptation or night blindness, a symptom primarily of vitamin A deficiency. During a placebo-controlled trial in Nepal, weekly vitamin A supplementation of women reduced but failed to eliminate the incidence of night blindness during pregnancy, suggesting a role for zinc. OBJECTIVE: The study examined the efficacy of daily zinc supplementation in restoring night vision of pregnant women who developed night blindness while routinely receiving either vitamin A, beta-carotene, or placebo in a field trial. DESIGN: Women (n = 202) who reported to be night blind during pregnancy were randomly assigned in a double-blind manner, stratified on vitamin A, beta-carotene, or placebo receipt, to receive 25 mg Zn or placebo daily for 3 wk. Thus, the 6 groups studied were as follows: beta-carotene + zinc, beta-carotene alone, vitamin A + zinc, vitamin A alone (vitamin A + placebo), zinc alone (zinc + placebo), and placebo (2 placebos: one for the vitamin A or beta-carotene study and one for the zinc study). Women underwent a clinic-based assessment that included pupillary threshold testing and phlebotomy before and after supplementation. Supplement use and daily history of night blindness were obtained at home twice every week. RESULTS: Zinc treatment increased serum zinc concentrations, but alone (zinc alone group), failed to restore night vision or to improve dark adaptation. However, women in the vitamin A + zinc group who had baseline serum zinc concentrations <9.9 micromol/L were 4 times more likely to have their night vision restored (95% CI: 1.1, 17.3) than were women in the placebo group and tended to have a small improvement in pupillary threshold scores (by 0.21 log candela/m2; P = 0.09). CONCLUSION: These data suggest that zinc potentiated the effect of vitamin A in restoring night vision among night-blind pregnant women with low initial serum zinc concentrations.

06
CLINICAL STUDY The Cochrane database of systematic reviews (2013) PMID: 24357340 ↗
Vitamin A and fish oils for retinitis pigmentosa.
Clinical Trial Synthesis 2013 Randomized Controlled Trial (RCT) published in The Cochrane database of systematic reviews involving n = 100,000 participants. Key conclusion: This field loss is progressive and usually does not reduce central vision until late in the disease course.The worldwide prevalence of RP is one in 4000, with 100,000 patients affected in the USA.
View Original PubMed Abstract ↓

BACKGROUND: Retinitis pigmentosa (RP) comprises a group of hereditary eye diseases characterized by progressive degeneration of retinal photoreceptors. It results in severe visual loss that may lead to legal blindness. Symptoms may become manifest during childhood or adulthood, and include poor night vision (nyctalopia) and constriction of peripheral vision (visual field loss). This field loss is progressive and usually does not reduce central vision until late in the disease course.The worldwide prevalence of RP is one in 4000, with 100,000 patients affected in the USA. At this time, there is no proven therapy for RP. OBJECTIVES: The objective of this review was to synthesize the best available evidence regarding the effectiveness and safety of vitamin A and fish oils (docosahexaenoic acid (DHA)) in preventing the progression of RP. SEARCH METHODS: We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2013, Issue 7), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to August 2013), EMBASE (January 1980 to August 2013), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to August 2013), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 20 August 2013. SELECTION CRITERIA: We included randomized controlled trials (RCTs) evaluating the effectiveness of vitamin A, fish oils (DHA) or both, as a treatment for RP. We excluded cluster-randomized trials and cross-over trials. DATA COLLECTION AND ANALYSIS: We pre-specified the following outcomes: mean change from baseline visual field, mean change from baseline electroretinogram (ERG) amplitudes, and anatomic changes as measured by optical coherence tomography (OCT), at one year; as well as mean change in visual acuity at five-year follow-up. Two authors independently evaluated risk of

07
META-ANALYSIS European journal of pediatrics (2026) PMID: 42008030 ↗
Different doses of vitamin A supplementation as adjuvant treatment for pneumonia in children: a network meta-analysis of randomized controlled trials.
Clinical Trial Synthesis 2026 Meta-Analysis published in European journal of pediatrics involving n = 3,116 participants. Key conclusion: • There are currently divergent conclusions in the research regarding the optimal dosage of vitamin A, particularly with regard to the safety of high-dose supplementation and the effectiveness of low-dose supplementation.
View Original PubMed Abstract ↓

While previous meta-analyses have established a link between vitamin A supplementation and outcomes in children with pneumonia, the efficacy and safety of different dosing regimens remain unclear. Existing evidence is predominantly based on single-dose trials, creating a critical knowledge gap. We systematically searched PubMed, Embase, Cochrane Library, Chinese National Knowledge Infrastructure, Wanfang and VIP databases from their inception to December 2025. Study searches were independently carried out in December 2025 by two reviewers. Two researchers used the Cochrane risk of bias tool to independently assess the quality of the included studies. Data analysis was conducted through the "netmeta" package in R software (version 4.3.3). Twenty-five trials involving 3116 patients were included. Network meta-analysis revealed that medium-dose vitamin A supplementation was most effective in reducing the duration of fever and cough. Low-to-medium doses were consistently associated with better clinical outcomes than high-dose regimens. However, evidence regarding safety outcomes remained limited and inconclusive. CONCLUSION: Low-to-medium dose vitamin A supplementation appears superior to high-dose regimens for alleviating clinical symptoms in children with pneumonia. However, the evidence is limited by high heterogeneity, indirect comparisons between dose groups, and poor reporting of adverse events. Future trials should prioritize direct dose-comparisons and rigorous safety monitoring to refine dosing guidelines. WHAT IS KNOWN: • Pneumonia poses a significant threat to the health and lives of children. Vitamin A supplementation plays an adjuvant role in the treatment of pneumonia in children. • There are currently divergent conclusions in the research regarding the optimal dosage of vitamin A, particularly with regard to the safety of high-dose supplementation and the effectiveness of low-dose supplementation. WHAT IS NEW: • This study revealed that medium-to-low-dose vitamin A supplementation appears to be more effective than high-dose therapy in alleviating the primary symptoms of childhood pneumonia. • This study also suggests that children in developed regions

08
CLINICAL STUDY Vaccine (2026) PMID: 41936264 ↗
Effects of neonatal Vitamin A supplementation on response to vaccinations in early infancy.
Clinical Trial Synthesis 2026 Randomized Controlled Trial (RCT) published in Vaccine involving n = 306 participants. Key conclusion: CONCLUSIONS: Neonatal VA modestly improved the DTH response to BCG but had no effect on antibody responses to OPV, TT and HBV.
View Original PubMed Abstract ↓

BACKGROUND: Vitamin A (VA) deficiency impairs immune function. STUDY DESIGN: A randomized, placebo-controlled intervention trial, stratified by sex and birthweight median (BWM), was conducted in 306 infants in Dhaka, Bangladesh to evaluate the effect of 50,000 IU VA given within 48 h of birth on responses to Bacillus Calmette Guérin (BCG), oral polio virus (OPV), Tetanus Toxoid (TT) and Hepatitis B virus (HBV) vaccines. METHODS: VA, BCG and OPV were administered within 48 h of birth. OPV was again administered at 6, 10 and 14 w with TT and HBV. Vaccine-specific responses included delayed-type hypersensitivity (DTH) at 15 w for BCG and antibody responses at 15 w (ex vivo PBMC secretion) and 2 y for OPV (IgA, IgG), TT (IgG) and HBV (IgG). T-cell proliferation and cytokine production (IFN-γ, IL-2, -4, -5, -10, -13 and -17A) in response to vaccine antigens and a polyclonal stimulus (staphylococcus enterotoxin B [SEB]) were measured at 6 w, 15 w and 2 y. Statistical analysis determined main effects of the intervention, and interactions with sex and birthweight. RESULTS: VA increased the DTH response in infants above the BWM but did not affect antibody responses to vaccines. The CD4 T-cell stimulation index (SI) was reduced by VA for BCG (6 w) and SEB (overall). VA increased TT- and HBV-specific IL-2 and IL-5 at 15 w and increased SEB-stimulated IL-5 in girls but decreased IL-5 in boys at 15 w. VA increased BCG-specific IL-13 and SEB-stimulated IL-5 in girls. VA decreased TT-specific and SEB-stimulated IL-17 in boys and decreased IL-10 in response to BCG, HBV (below BWM only) and SEB at 15 w. CONCLUSIONS: Neonatal VA modestly improved the DTH response to BCG but had no effect on antibody responses to OPV, TT and HBV. VA affected CD4 T-cell function, at times in a sex-specific manner. TRIAL REGISTRY: This trial is registered at Clinical. TRIALS: gov. Registry numbers are NCT015839720 and NCT02027610. Published by Elsevier Ltd.

09
CLINICAL STUDY Cancer epidemiology, biomarkers & prevention (2026) PMID: 41524587 ↗
Effect Modification by Serum Vitamin A Levels on the Association between Vitamin D and Relapse or Death in Patients with Digestive Tract Cancer.
Clinical Trial Synthesis 2026 Randomized Controlled Trial (RCT) published in Cancer epidemiology, biomarkers & prevention involving n = 363 participants; statistical significance reported at p = 0.0001 (HR 2.05). Key conclusion: CONCLUSIONS: Vitamin D supplementation may reduce relapse and death among patients with middle-to-upper range of serum vitamin A levels.
View Original PubMed Abstract ↓

BACKGROUND: Vitamin D interacts with vitamin A through receptor heterodimerization. This post hoc analysis of the AMATERASU randomized clinical trial (RCT) of vitamin D3 supplementation examined whether serum vitamin A levels modify the association of vitamin D with relapse or death in patients with digestive tract cancer. METHODS: The primary outcome was relapse or death. Relapse-free survival (RFS) was evaluated using Nelson-Aalen cumulative hazard functions and Cox proportional hazards models. Serum vitamin A levels were categorized stepwise using clinical reference ranges and quantile cutoffs (halves, tertiles, quartiles, quintiles, and deciles), with post hoc grouping of the most coherent quantiles for analysis. RESULTS: Among 363 patients (mean age, 66 years; 67.8% male), serum vitamin A ranged from 0.15 to 4.30 μmol/L [median (IQR), 1.38 (1.05-1.74)] and correlated positively with 25-hydroxyvitamin D (ρ = 0.31; P < 0.0001). Patients in the lowest decile had higher relapse or death risk [HR, 2.05; 95% confidence interval (CI), 1.10-3.84; P = 0.03] than those in deciles 2 to 10. In the middle range (deciles 6-8), 5-year RFS was greater with vitamin D versus placebo (81.4% vs. 54.9%; HR, 0.31; 95% CI, 0.14-0.69; P = 0.004), with no effect in lower (deciles 1-5) or higher (deciles 9-10) ranges (Pinteraction = 0.008). CONCLUSIONS: Vitamin D supplementation may reduce relapse and death among patients with middle-to-upper range of serum vitamin A levels. IMPACT: These exploratory findings provide the first RCT evidence that serum vitamin A levels modify the effect of vitamin D supplementation on relapse or death among patients with digestive tract cancer. ©2026 American Association for Cancer Research.

10
RANDOMIZED TRIAL (RCT) European journal of nutrition (2025) PMID: 41417236 ↗
Assessment of vitamin A, vitamin B(2), vitamin B(12), vitamin K, folate, and choline status following 4 months of multinutrient supplementation in healthy vegans: a randomised, double-blind, placebo-controlled trial.
Clinical Trial Synthesis 2025 Randomized Controlled Trial (RCT) published in European journal of nutrition. Key conclusion: CONCLUSION: A multinutrient supplement containing 82 µg of vitamin B12 per day significantly positively affected vitamin B12 blood biomarkers in healthy vegans.
View Original PubMed Abstract ↓

PURPOSE: The aim of the MultiVeg study, a double-blind, randomised controlled trial (RCT), was to investigate the nutritional status of healthy vegans following 4 months of multinutrient supplementation. METHODS: A double-blind, RCT was conducted with 72 vegan adults (19-57 years) in Germany. Data on anthropometric parameters, dietary nutrient intake, and nutritional status were collected. The nutritional status of the participants was assessed at baseline and after 4 months. The results were compared between groups using ANCOVA. The results for vitamins and choline are presented here. RESULTS: After adjustment for baseline values, age, sex, and multiple testing, no significant between-group differences in biomarker concentration changes from baseline to 4 months were observed for vitamin A, retinol-binding protein, transthyretin, beta-carotene, methylmalonic acid, homocysteine, choline, total osteocalcin, carboxylated and undercarboxylated osteocalcin, and folate. In contrast, significant between-group differences in changes were observed for flavin adenine dinucleotide (FAD), serum vitamin B12, holotranscobalamin, and the combined vitamin B12 status indicator (cB12) after adjustment. CONCLUSION: A multinutrient supplement containing 82 µg of vitamin B12 per day significantly positively affected vitamin B12 blood biomarkers in healthy vegans. REGISTRATION: This study was registered in the German Clinical Trials Register (DRKS00028151). © 2025. The Author(s).

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