Vitamin B supplementation and blood pressure in adults: an umbrella review of meta-analyses of randomized controlled trials

Q: What are the key findings of this study?

Folic acid supplementation reduced systolic blood pressure in adults, while niacin reduced both systolic and diastolic blood pressure.

Q: What is the clinical evidence from this study?

Study design: Meta-Analysis. Population: Blood pressure regulation in adults (including healthy individuals and those with cardiovascular disease, hypertension, or metabolic disorders) (n=21755). Intervention: Vitamin B supplementation (primarily Folic acid and Niacin) vs. Control / Placebo. Primary outcome: Systolic blood pressure (SBP) reduction with folic acid supplementation (WMD -1.40 mmHg, 95% CI -2.36 to -0.45, p=<0.001).

Q: What does this research mean for the field?

Folic acid supplementation modestly lowers systolic blood pressure with low certainty of evidence, while niacin lowers both systolic and diastolic blood pressure, with no significant blood pressure-lowering effects observed for other B vitamins. Novelty: ClaimNovelty.SYNTHESIS. Consensus alignment: ConsensusAlignment.NEUTRAL.

Q: What question did this study set out to answer?

To synthesize the evidence on the effects of vitamin B supplementation on systolic and diastolic blood pressure in adults through an umbrella review of meta-analyses of randomized controlled trials.

Ali Kosari; Shayesteh Fazilat; Hossein Shahinfar; Faezeh Dehghani-Tafti; Abbas Andishmand; Majid Mahmoudi Moghadam; Sepideh Soltani

doi:10.1186/s12986-026-01240-y

November 14, 2026Nutrition & MetabolismOpen Access

Vitamin B supplementation and blood pressure in adults: an umbrella review of meta-analyses of randomized controlled trials

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Key result

Folic acid supplementation reduces systolic blood pressure by ~1.4 mmHg in adults.

WMD -1.40 mmHg
95% CI -2.36 to -0.45
P<0.001
n=21,755

Why the study?

Findings from previous meta-analyses examining the effects of vitamin B supplementation on blood pressure in adults have been inconsistent.

Does vitamin B supplementation reduce systolic and diastolic blood pressure in adults?

Key Points

To synthesize the evidence on the effects of vitamin B supplementation on systolic and diastolic blood pressure in adults through an umbrella review of meta-analyses of randomized controlled trials.
Conducted a systematic search across PubMed, Scopus, Embase, Web of Science Core Collection, and Cochrane through June 2026, identifying 10 meta-analyses encompassing 26 randomized controlled trials.
Extracted effect sizes from individual trials and reanalyzed them using random-effects models to derive pooled weighted mean differences with 95% confidence intervals.
Assessed methodological quality of meta-analyses using the AMSTAR 2 tool and evaluated certainty of evidence using the GRADE approach.
Folic acid supplementation reduced SBP (WMD: −1.40 mmHg; 95% CI: −2.36 to − 0.45; I² = 59.94%; 19 studies) with low certainty of evidence, but showed no significant effect on DBP (moderate certainty of evidence).
Niacin supplementation significantly reduced both SBP (WMD: -2.84 mmHg; 95% CI: -3.47, -2.21; I² = 0) and DBP (WMD: -2.13 mmHg; 95% CI: -2.54, -1.73; I² = 0), though evidence was limited to 3 trials.

Study Design

Type

Meta-Analysis (n=21,755)

Randomization

Randomized controlled trials

Multicenter

Yes

Structured PICO

Does vitamin B supplementation reduce systolic and diastolic blood pressure in adults?

P

Population

21,755 adults across 26 randomized controlled trials (from 10 meta-analyses) including both healthy individuals and patients with cardiovascular or metabolic disorders, followed for 4 to 240 weeks.

I

Intervention

Vitamin B supplementation (folic acid 0.4 to 10 mg/day, nicotinic acid/niacin 1000 to 3000 mg/day, vitamin B6 10 mg/day, vitamin B1 300 mg/day, vitamin B2 1.6 mg/day, and vitamin B12 0.5 mg/day) for durations ranging from 4 to 240 weeks.

C

Comparator

Control group (not explicitly detailed across all pooled trials).

O

Outcome

Resting or ambulatory systolic blood pressure (SBP) and diastolic blood pressure (DBP) (in mmHg) over study durations of 4 to 240 weeks.surrogate

Main Result

Mean Difference: -1.4 (95% CI -2.36–-0.45)

p-value: p=<0.001

This umbrella review of meta-analyses demonstrates that folic acid supplementation modestly reduces systolic blood pressure by 1.40 mmHg (low certainty of evidence), while niacin reduces both systolic and diastolic blood pressure based on limited trial data.

Limitations

Uncertain long-term impact as few included trials conducted follow-up beyond six months
Moderate heterogeneity across included studies for systolic blood pressure that was not fully explained by subgroup analyses
Unmeasured confounding factors such as dietary intake, physical activity, and baseline serum vitamin B levels were not addressed in some trials
Low certainty of evidence for folic acid on SBP and limited number of trials (only 3) evaluating niacin directly
Uncertain long-term impact of vitamin B supplementation on blood pressure as few studies conducted follow-up beyond six months
Moderate heterogeneity across included studies for SBP (I² = 59.94%) not explained by subgroup analyses
Unmeasured or insufficiently reported factors such as dietary intake, physical activity, and baseline serum vitamin B levels
Evidence for niacin was limited to only three trials after excluding niacin precursors
Very high degree of overlap across the ten included meta-analyses (CCA 24.8%)

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Implication

Modest BP reductions do not support routine supplementation; extends prior meta-analyses with low-certainty data for folic acid and limited trials for niacin.

Abstract

Several meta-analyses have examined the effects of vitamin B supplementation on blood pressure, but their findings remain inconsistent. We aimed to provide a comprehensive summary of the effects of vitamin B supplementation on blood pressure in adults through an umbrella review of randomized controlled trials (RCTs). A systematic search was conducted in PubMed, Scopus, Embase, Web of Science Core Collection, and Cochrane up to June 2026. For each included meta-analysis, we extracted the effect sizes of individual RCTs and reanalyzed them using random-effects models to obtain pooled estimates with 95% confidence intervals. The certainty of evidence was assessed using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) approach. Ten meta-analyses including 26 RCTs were identified. Folic acid supplementation reduced SBP (WMD: −1.40 mmHg; 95% CI: −2.36 to − 0.45; I² = 59.94%; 19 studies) but had no significant effect on DBP. Niacin supplementation was associated with reductions in both SBP (WMD: -2.84 mmHg; 95% CI: -3.47, -2.21; I² = 0) and DBP (WMD: -2.13 mmHg; 95% CI: -2.54, -1.73; I² = 0), although evidence was limited to three trials. No significant blood pressure-lowering effects were observed for the remaining B vitamins. Folic acid supplementation may modestly lower SBP, though certainty of evidence for SBP was low. Evidence for niacin and other B vitamins remains insufficient, and further RCTs are needed.

Discussion

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Cite This Study

Kosari et al. (2026) conducted a meta-analysis in Blood pressure regulation in adults (including healthy individuals and those with cardiovascular disease, hypertension, or metabolic disorders) (n=21,755). Vitamin B supplementation (primarily Folic acid and Niacin) vs. Control / Placebo was evaluated on Systolic blood pressure (SBP) reduction with folic acid supplementation (WMD -1.40 mmHg, 95% CI -2.36 to -0.45, p=<0.001). Folic acid supplementation reduced systolic blood pressure in adults, while niacin reduced both systolic and diastolic blood pressure.

synapsesocial.com/papers/6af9ebcdd393cbc380a05038 https://doi.org/10.1186/s12986-026-01240-y

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Vitamin B supplementation and blood pressure in adults: an umbrella review of meta-analyses of randomized controlled trials

Key Points

Study Design

Structured PICO

Main Result

Limitations

Ask about this paper

Implication

Abstract

Discussion

Cite This Study

Vitamin B supplementation and blood pressure in adults: an umbrella review of meta-analyses of randomized controlled trials

Key Points

Study Design

Structured PICO

Main Result

Limitations

Ask about this paper

Implication

Abstract

Discussion

Cite This Study

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