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Supplement × Supplement·Evidence index

Methylcobalamin and Vitamin B9: what the research found

PubMed indexes 8 records that name Methylcobalamin and Vitamin B9 together, either in the title or in an interaction, co-administration, or pharmacokinetic context. The key findings come first, in the authors’ own words, followed by every study with its design and PubMed link.

A summary of published research, not medical advice. A pharmacist can check any combination against your full list of medicines and supplements.

Key findings

What the studies concluded.

Reviews and human studies first. Each quote is the authors’ own conclusion about their study, not a NutriStack assessment, and a single study is not a consensus.

“A three-month supplementation with a combination of 800 mcg methylfolate and 1000 mcg methylcobalamin showed promise in lowering blood pressure and serum homocysteine levels in ESRD patients with resistant hypertension. These findings require additional exploration in larger studies.”

Salem et al. · 2026 · Human study · details

“However, vitamin B12 and folate levels may not strongly influence MCI. Routine assays for these vitamins in elderly individuals with cognitive impairment should be reconsidered in resource-constrained settings.”

Kuchipudi et al. · 2026 · Human study · details

“LDL-C levels decreased by 11.8% in homozygous carriers (95% CI: -15.8% to -7.8%, p < 0.01) and 4.8% in mixed allele carriers (95% CI: -6.8% to -2.8%, p < 0.01), with a significant between-group difference (7.0%, 95% CI: -13.0% to -1.0%, p < 0.01). Methylfolate, P5P, and methylcobalamin supplementation tailored to genetic profiles effectively reduced homocysteine and LDL-C levels in patients with specific MTHFR,…”

The research

8 studies naming Methylcobalamin and Vitamin B9.

Strongest relevance first: papers naming both substances in the title, then human trials and systematic reviews.

Efficacy of L-methylfolate and methylcobalamin in treating resistant hypertension associated with elevated serum homocysteine in hemodialysis patients.

BMC nephrology · 2026 · PMID 41580678

Clinical Trial, Phase IVRandomized Controlled Trial

“A three-month supplementation with a combination of 800 mcg methylfolate and 1000 mcg methylcobalamin showed promise in lowering blood pressure and serum homocysteine levels in ESRD patients with resistant hypertension. These findings require additional exploration in larger studies.”

Salem et al. · Authors' conclusion

Names both Methylcobalamin and Vitamin B9 in its title.

Effect of Methylfolate, Pyridoxal-5'-Phosphate, and Methylcobalamin (Soloways(TM)) Supplementation on Homocysteine and Low-Density Lipoprotein Cholesterol Levels in Patients with Methylenetetrahydrofolate Reductase, Methionine Synthase, and Methionine Synthase Reductase Polymorphisms: A Randomized Controlled Trial.

Nutrients · 2024 · PMID 38892484

Randomized Controlled Trial

“LDL-C levels decreased by 11.8% in homozygous carriers (95% CI: -15.8% to -7.8%, p < 0.01) and 4.8% in mixed allele carriers (95% CI: -6.8% to -2.8%, p < 0.01), with a significant between-group difference (7.0%, 95% CI: -13.0% to -1.0%, p < 0.01). Methylfolate, P5P, and methylcobalamin supplementation tailored to genetic profiles effectively reduced homocysteine and LDL-C levels in patients with specific MTHFR, MTR, and MTRR polymorphisms, particularly with homozygous minor…”

Pokushalov et al. · From the abstract

Names both Methylcobalamin and Vitamin B9 in its title.

Randomized controlled trial of the effect of short-term coadministration of methylcobalamin and folate on serum ADMA concentration in patients receiving long-term hemodialysis.

American journal of kidney diseases : the official journal of the National Kidney Foundation · 2010 · PMID 20430500

Randomized Controlled Trial20 participants

“Coadministration of intravenous methylcobalamin and oral folate in hemodialysis patients normalized hyperhomocysteinemia and decreased ADMA levels and arterial stiffness. We suggest that this regimen may have greater potential than folate alone to decrease cardiovascular risk in such patients.”

Koyama et al. · Authors' conclusion

Names both Methylcobalamin and Vitamin B9 in its title.

Randomized trial of methylcobalamin and folate effects on homocysteine in hemodialysis patients.

Nephron · 2002 · PMID 12021520

Clinical TrialRandomized Controlled Trial

“Oral FA (10 mg/day) supplementation appears to be an effective approach to normalize plasma tHcy in chronic HD patients; the addition of i.v. Me-Cbl (500 microg twice/week) to this regimen showed no benefit. Separately, FA corrected hyperhomocysteinemia (HtHcy), while Me-Cbl showed no change.”

Trimarchi et al. · Authors' conclusion

Names both Methylcobalamin and Vitamin B9 in its title.

Gender differences in methylcobalamin, folate, homocysteine, and hemoglobin levels among urban, community dwelling, elderly with mild cognitive impairment in a South Indian city: A cross-sectional study.

Journal of Alzheimer's disease : JAD · 2026 · PMID 41940848

Human subjects

“However, vitamin B12 and folate levels may not strongly influence MCI. Routine assays for these vitamins in elderly individuals with cognitive impairment should be reconsidered in resource-constrained settings.”

Kuchipudi et al. · From the abstract

Names both Methylcobalamin and Vitamin B9 in its title.

Pregnancy outcomes in women with epilepsy and MTHFR mutations supplemented with methylated folate and methylcobalamin (methylated B12).

Epilepsy & behavior reports · 2020 · PMID 33426516

“Their pregnancy outcomes improved with L-methylfolate and methylcobalamin supplementation. L-methylfolate and methylcobalamin supplementation merits further study in WWE who have MTHFR mutations, fertility, recurrent miscarriage and or depression histories.”

Lascar et al. · From the abstract

Names both Methylcobalamin and Vitamin B9 in its title.

Prenatal arsenic exposure and dietary folate and methylcobalamin supplementation alter the metabolic phenotype of C57BL/6J mice in a sex-specific manner.

Archives of toxicology · 2018 · PMID 29721587

Animal study

“These results suggest that prenatal iAs exposure impairs glucose metabolism in a sex-specific manner and that maternal folate/B12 supplementation may improve the metabolic phenotype in offspring. Further studies are needed to identify the mechanisms underlying these effects.”

Huang et al. · From the abstract

Names both Methylcobalamin and Vitamin B9 in its title.

Limitations

What this evidence cannot tell you.

Search-based evidence indexes have real limits, and it is worth being explicit about them:

How to read this page

A literature summary, not guidance.

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