Homocysteine

Meta-analysis or review · 1 study linked

Studied in: Adults

8 corpus studies (cardiac cluster) + 8 (methylation cluster). No extracted RCT endpoint data. Gap.

• Effect of nutritional supports on malnutrition, cognition, function and biomarkers of Alzheimer's disease: a systematic review. (2023)

Modest effect · 4 studies linked

Studied in: Adults, Hypomagnesemia, MTHFR variant, General adult

Inverse Mg–tHcy association confirmed in large multi-ethnic general adult cohort (MESA, n=5,181, p-trend <0.001). Effect present even in non-metabolic, CVD-free adults suggesting pathway not confined to high-risk populations. Absolute magnitude modest in observational context; RCT effect sizes in deficient populatio...

• Veronese N, Pizzol D, Demurtas J, et al. (2022)
• de Oliveira Otto MC, Alonso A, Lee DH, Delclos GL, Jenny NS, Jiang R, Lima JA, Symanski E, Jacobs DR Jr, Nettleton JA (2011)
• Total, Dietary, and Supplemental Magnesium Intakes and Risk of All-Cause, Cardiovascular, and Cancer Mortality: A Systematic Review and Dose-Response Meta-Analysis of Prospective Cohort Studies. (2021)
• Zhang (2022) · not matched to a paper yet

Meta-analysis or review · 2 studies linked

23 studies in corpus; direction not consistently extractable. Theoretical basis for interaction: carnitine biosynthesis requires S-adenosylmethionine, competing with homocysteine remethylation. See OQ-019.

• Associations of circulating choline and its related metabolites with cardiometabolic biomarkers: an international pooled analysis (2021)
• Propionyl-L-carnitine therapy: effects on endothelin-1 and homocysteine levels in patients with peripheral arterial disease and end-stage renal disease. (2006)

Human trials · 1 study linked

Studied in: Adults with elevated SAH

• Lowering plasma S-Adenosylhomocysteine (SAH) in healthy adults with elevated SAH and normal homocysteine using nutritional supplementation. (2025)

Human trials · 1 study linked

• Combined nutraceutical approach to postmenopausal syndrome and vascular remodeling biomarkers. (2013)

Human trials · 1 study linked

• Low daily dose of 3 mg monacolin K from RYR reduces the concentration of LDL-C in a randomized, placebo-controlled intervention. (2016)

Human trials · 1 study linked

Studied in: Coronary artery disease

• Effects of coenzyme Q10 supplementation on inflammatory markers (high-sensitivity C-reactive protein, interleukin-6, and homocysteine) in patients with coronary artery disease (2012)

Human trials · 1 study linked

Studied in: General

28 corpus studies. Merged from duplicate cardiac/methylation cluster entries. Secondary tag: cardiac_risk_marker. Taurine's indirect relationship to homocysteine is via the transsulfuration pathway (cysteine → taurine via CDO1/CSAD diverts from homocysteine → cysteine direction), but supplemental taurine does not re...

• Biomarkers of oxidative stress, inflammation, and vascular dysfunction in inherited cystathionine β-synthase deficient homocystinuria and the impact of taurine treatment in a phase 1/2 human clinical (2019)

Meta-analysis or review · 2 studies linked

Studied in: Subfertile males, Adults

Zinc has no direct enzymatic role in methionine cycle. Homocysteine metabolism depends on folate (MTHFR), B12, and B6. li_2023 MA (folate+zinc, n=2,168) effect attributable to folate component. Not a homocysteine-lowering strategy. NOTE: Empty duplicate entry with biomarker_id 'homocysteine' (all blank fields) shoul...

• Zinc/carbon nanomaterials inhibit antibiotic resistance genes by affecting quorum sensing and microbial community in cattle manure production. (2023)
• Investigation of the clinical efficacy of Zn supplementation in improvement of oxidative stress parameters: A systematic review and dose-response meta-analysis of controlled clinical trials. (2021)

Small effect · 1 study linked

Studied in: Adult, Cvd risk, General

• Huang T, Wahlqvist ML, Xu T, Xu A, Zhang A, Li D (2018)

Human trials · 8 studies linked

Studied in: General adult, Healthy adults

Canonical entry (methylation cluster). Theoretical SAM-sparing mechanism suggests creatine should lower homocysteine — not confirmed in available RCTs. Available studies show no significant plasma homocysteine change, suggesting compensatory regulation. MTHFR 677TT subgroup unstudied.

• Differential response of muscle phosphocreatine to creatine supplementation in young and old subjects. (2002)
• Provision of folic acid for reducing arsenic toxicity in arsenic-exposed children and adults. (2021)
• Lowering plasma S-Adenosylhomocysteine (SAH) in healthy adults with elevated SAH and normal homocysteine using nutritional supplementation. (2025)
• Rehydration during exercise prevents the increase of homocysteine concentrations. (2019)
• Creatine supplementation alters homocysteine level in resistance trained men. (2015)
• Low-Dose Creatine Supplementation Lowers Plasma Guanidinoacetate, but Not Plasma Homocysteine, in a Double-Blind, Randomized, Placebo-Controlled Trial. (2015)
• +2 more studies

Human trials · Negligible effect · 3 studies linked

Studied in: General adult

• Vitamin D (2021)
• The Impact of the Dietary Intake of Vitamin B12, Folic Acid, and Vitamin D3 on Homocysteine Levels and the Health-Related Quality of Life of Levodopa-Treated Patients with Parkinson's Disease-A Pilot (2024)
• Improving the endothelial dysfunction in type 2 diabetes with chromium and vitamin D (2020)

Meta-analysis or review · Small effect · 6 studies linked

Studied in: Cardiovascular risk, Adult, Renal failure, CKD

Direct homocysteine lowering is not a reliable NAC effect despite transsulfuration pathway involvement.

• PubMed 26325010
• PubMed 22396493
• PubMed 15866356
• Effect of N-acetylcysteine administration on homocysteine level, oxidative damage to proteins, and levels of iron (Fe) and Fe-related proteins in lead-exposed workers. (2016)
• A randomized placebo-controlled pilot study of N-acetylcysteine in youth with autism spectrum disorder. (2016)
• N-acetylcysteine for chronic kidney disease: a systematic review and meta-analysis. (2021)

Human trials · 3 studies linked

Studied in: Adults overweight obese, European finnish, Lean subgroup, Healthy

Direction discordance resolved as duration-dependent: null at 8 weeks, increased in lean subgroup at 5 months. Aggregate direction = contested. Mechanistically plausible via NNMT-mediated methyl donor depletion. Duplicate cardiac-cluster entry removed; this is the canonical entry.

• Nicotinamide riboside improves muscle mitochondrial biogenesis, satellite cell differentiation, and gut microbiota in a twin study (2023)
• Safety and Metabolism of Long-term Administration of NIAGEN (Nicotinamide Riboside Chloride) in a Randomized, Double-Blind, Placebo-controlled Clinical Trial of Healthy Overweight Adults. (2019)
• NR-SAFE: a randomized, double-blind safety trial of high dose nicotinamide riboside in Parkinson’s disease (2023)